Search Results

Search found 8250 results on 330 pages for 'dunn less'.

Page 282/330 | < Previous Page | 278 279 280 281 282 283 284 285 286 287 288 289  | Next Page >

• Exchange-Server Query

  - by Rudi Kershaw

  First, a little background. I've recently been taken on as a web and software developer for a small company, who has no other in-house IT support. They've been asking my opinion on lots of IT subjects that are quite far out of my comfort zone. I'm definitely not a network admin. Their IT consultancy contractor is pushing them to upgrade their dedicated exchange server, even though it seems like the one they currently have has a lot of life left in it and is running problem free. They say it's "coming to the natural end of it's life". They want to install a monster with a Xeon E5-2420, 32GB RAM, 2x 1TB HDDs, Windows Server 2012 and Microsoft Exchange 2010. They want to charge a small fortune for it. Basically, this system seems massively over the top seeing as it won't be doing anything else other than running as an exchange server for a company with less than 25 email accounts. My employers also have a file server system in-house that hosts three web apps, an SQL server, their local domain, print server and shared folders. That machine is using the same specs as the proposed new one, and it is barely using any of it's potential. I asked if Microsoft Exchange 2010 could be installed on their file server, but they said that MS Exchange can't run on the same system as an SQL server because for some reason they will eat up each others resources (even though the SQL server isn't touching 1% of the current system's CPU or RAM). My question is really, are they trying to rip my employers off? Could MS Exchange be installed on their other server (on a virtual instance or not), or does the old one even need replacing at all? Going with their current suggestion will cost the company in excess of £6k, and it seems entirely unnecessary. I apologies, because I know this is probably a little thin on details, but if I carry on I could end up writing a massive essay that no-one will want to read. I've been doing my research, but I'm not knowledgeable enough make any hard decisions. Let me know if you need any more details. Thank you for any help you can offer. Further Details: The new exchange would need to support Outlook Web App, 25 users, a few public mailboxes, and email exchange with Blackberries.

  Read the article

• networked storage for a research group, 10-100 TB

  - by Marc

  this is related to this post: http://serverfault.com/questions/80854/scalable-24-tb-nas-for-research-department but perhaps a little more general. Background: We're a research lab of around 10 people who do a lot of experiments that involve taking pictures at one of several lab setups and then analyzing it an one of several lab computers. Each experiment may produce 2 or 3 GB of data, and we are generating data at the rate of about 10 TB/year. Right now, we are storing the data on a 6-bay netgear readynas pro, but even with 2 TB drive, this only gives us 10 TB of storage. Also, right now we are not backing up at all. Our short term backup plan is to get a second readynas, put it in a different building and mirror the one drive onto the other. Obviously, this is somewhat non-ideal. Our options: 1) We can pay our university $400/ TB /year for "backed up" online storage. We trust them more than we trust us, but not a whole lot. 2) We can continue to buy small NASs and mirror them between offices. One limit, although stupid, is that we don't have an unlimited number of ethernet jacks. 3) We can try to implement our own data storage solution, which is why I'm asking you guys. One thing to consider is that we're a very transient population and none of us are network administration experts. I will probably be here only another year or so, and graduate students, who are here the longest, have a 5-6 year time scale. So nothing can require expert oversight. Our data transfer rates are low - most of the data will just sit on the server waiting for someone to look at it once or twice - so we don't need a really high speed system. Given these contraints, can someone recommend a fairly low-cost, scalable, more or less turn key shared data storage system with backup in a separate physical location. Does such a thing exist or should we just pay the university to take care of it for us? As a second question, our professor just got tenure and is putting together a budget. Here the goal is to ask for as much as you can and hope you get a fraction of it. So the same question, minus the low-cost. Without budget constraints, can you recommend a scalable turn-key backed up storage system. Thanks

  Read the article

• How to tune system settings for mongoDB on Linux?

  - by jsh

  Trying to squeeze a lot out of one question here -- please bear with me. Although the MongoDB man pages make several useful recommendations about system settings like ulimit (http://docs.mongodb.org/manual/reference/ulimit/), and other production factors (http://docs.mongodb.org/manual/administration/production-notes/) they seem mysteriously silent on things like virtual memory and swap settings. The closest we get to a hint is that "...the operating system’s virtual memory subsystem manages MongoDB’s memory..." (http://docs.mongodb.org/manual/faq/fundamentals/#does-mongodb-require-a-lot-of-ram). Running the same job - high writes and high reads on about 10,000,000 records in a single collection -- on my 4-processor, 4GB RAM macbook and an 8-core ubuntu box with 64GB RAM I saw dramatically WORSE read performance on the linux box with factory settings, and could hear the disk constantly spinning, indicating high I/O and presumably swapping. Yes, other things were happening on the box, but there was plenty of free RAM, disk space, etc.; furthermore, I did not see evidence that Mongo was expanding to take advantage of all that free RAM as it is touted to do. Linux box default settings were as follows: vm.swappiness =60 vm.dirty_background_ratio = 10 vm.dirty_ratio = 20 vm.dirty_expire_centisecs =3000 vm.dirty_writeback_centisecs=500 I hazarded some guesses looking at docs and blogs for other types of databases (Oracle, MYSQL, etc.), experimented, and adjusted as below. vm.swappiness=10 vm.dirty_background_ratio=5 vm.dirty_ratio=5 vm.dirty_writeback_centisecs=250 vm.dirty_expire_centisecs=500 I saw some immediate apparent improvements in read time. However, when I ran my test jobs again, read performance continued to be painfully sluggish during heavy writes. Then, I REBUILT the collection from an available data source - and suddenly I can read at 1ms or less per record WHILE doing the write job! So the question is really two-fold: 1) What are appropriate VM settings for MongoDB on Linux? 2) (bonus) Does Mongo do some checking or optimization with the OS while data is being built? In other words, if I have built a large data set with suboptimal VM or I/O settings, does Mongo make assumptions during the memory-mapping process that will fail to take advantage of optimizations down the road? Obviously I don't fully grok memory mapping under the hood (I was hoping I wouldn't have to). Any help appreciated...thanks! -j

  Read the article

• NFS4 / ZFS: revert ACL to clean/inherited state

  - by Keiichi

  My problem is identical to this Windows question, but pertains NFS4 (Linux) and the underlying ZFS (OpenIndiana) we are using. We have this ZFS shared via NFS4 and CIFS for Linux and Windows users respectively. It would be nice for both user groups to benefit from ACLs, but the one missing puzzle piece goes thusly: Each user has a home, where he sets a top-level, inherited ACL. He can later on refine permissions for the contained files/folders iteratively. Over time, sometimes permissions need to be generalized again to avoid increasing pollution of ACL entries. You can tweak the ACL of every single file if need be to obtain the wanted permissions, but that defeats the purpose of inherited ACLs. So, how can an ACL be completely cleared like in the question linked above? I have found nothing about what a blank, inherited ACL should look like. This usecase simply does not seem to exist. In fact, the solaris chmod manpage clearly states A- Removes all ACEs for current ACL on file and replaces current ACL with new ACL that represents only the current mode of the file. I.e. we get three new ACL entries filled with stuff representing the permission bits, which is rather useless for cleaning up. If I try to manually remove every ACE, on the last one I get chmod A0- <file> chmod: ERROR: Can't remove all ACL entries from a file Which by the way makes me think: and why not? In fact, I really want the whole file-specific ACL gone. The same holds for linux, which enumerates ACEs starting with 1(!), and verbalizes its woes less diligently nfs4_setacl -x 1 <file> Failed setxattr operation: Unknown error 524 So, what is the idea behind ACLs under Solaris/NFS? Can they never be cleaned up? Why does the recursion option for the ACL setting commands pollute all children instead of setting a single ACL and making the children inherit? Is this really the intention of the designers? I can clean up the ACLs using a windows client perfectly well, but am I supposed to tell the linux users they have to switch OS just to consolidate permissions?

  Read the article

• git, egit, submodules, and symlinks -- how should shared sub-projects be handled in eclipse?

  - by Autophil

  Here's the situation. I have a few git projects with a directory structure layed out more or less like this: simpleproj app www admin demo lib model orm view model user blah ... storeproj app www about mobile fbapp lib model orm view model user message cart product merchant Each directory in "lib" contains a separate project, either created in-house or forked, all of which use git for source control. So I figured I should make them submodules of my projects, right? Well, we've been moving toward eclipse + egit, because some of our windows guys not used to a CLI need something they can use without being scared of screwing things up. Anyway, the problem is, egit doesn't support submodules. So, my solution has been a rather crude one involving symlinks... lets say my directory structure on my dev box is generally layed out like this: ~/projects/ bigproj .git app lib model (- ~/lib/model/src/) orm (- ~/lib/orm/src/) neatproj .git app lib view (- ~/lib/view/src/) oldproj .git app lib orm (- ~/lib/orm/src/) ~/lib/ model .git src README.md orm .git src COPYING view .git src ...the symlinks link inside of directory with the git repo, so eclipse doesn't get confused, and everything sort of works. On my machine, I can update the libs from anywhere and all projects will be updated (needing to be committed again of course). Each project stores a separate copy of the contents of the symlinked directories within "lib" -- but only when staged from within eclipse. After committing from eclipse and moving back to the CLI, git sees that a bunch of files have been removed and a few symlinks have been created. Of course this is acceptable also, probably more so than keeping a separate history of the libs for each project... but eclipse and CLI git obviously need to be on the same page so tons of files aren't vanishing and reappearing. So this brings me to my question. I'd like to know how to either: get eclipse+egit to see the symlinks as symlinks if git will somehow handle them properly*, or get the CLI git to treat them as non-symlinks. Or, if there's a better way to do this, I'm all ears. Hope this all made sense! :D Note: tried to tag this as git-submodules, but was not allowed :( * should I make them relative or absolute? Either way it's a mess. Also will symlinks will work on windows? i know there's something similar but you need a 3rd party tool to manage them AFAIK, i doubt these would translate well.

  Read the article

• Start a software company offshore

  - by Mascarpone

  Hello Everybody, I own a small, very young, EU based (Italy) company, and among other things, we sell IT solutions. I have a degree in applied mathematics, and I mainly deal with user interfaces, embedded systems, automation and web applications. You can say that I'm an enlightened entrepreneur because I work only with open source software (OS, IDE, I release under BSD , ... everything is free as in freedom), I give high importance to post sales services and customer satisfaction, plus I think I'm the best boss someone could desire (LOL), as I have google in mind when I think about IT workers rights. But the most beautiful thing is that, although everybody advised us not to use open source, is that we are quite profitable!!! (for the sixth trimester in a row). Now I offshore most of the work to an Indian company. I divide the work in modules and I outsource the longer or more trivial ones. I spend a lot of time defining the specifications and I leave the hard work to them. Using productivity bonuses, a lot of prototypes and third-party audits I think that my software has reached a very good quality level. I would like to start my own software development company, in order to improve control over process and cut costs. Obviously I can't afford the cost of labor in the EU, so I thought about opening a company in Asia. What I need Is: 1) Cheap labor - I can afford to give productivity bonuses and higher than average wages and stay profitable just because labor is cheap. 2) Many talents - I need a good level of tertiary education, and a good number of graduates, so I can hire junior developers and train and teach them according to my needs and philosophies (e.g.: open source mind) 3) Good infrastructure - buildings, transport, internet, .... everything that a company might need. I thought about 3 possible candidates: 1) India - I already work with indian people, I know that they are realiable and speak a good english. Big cities are too expensive, but maybe a small city like lucknow http://en.wikipedia.org/wiki/Lucknow could suits my needs. 2) China - They say it's cheaper than India, but I everytime I worked with a chineese company the language was a big barrier. They work hard, are somewhat skilled and cheap but maybe it's a risky path. Plus I feel a little uncofortable with their lack of human rights. 3) Philippines - Same as china: cheaper than india, but maybe less educated. Where do you think it's the best place to start a software company? Any reading or book to advise? thank you very much

  Read the article

• I have been told to accept one error with Memtest86+

  - by DustByte

  Bought a new computer back in August with 4x4 GB RAM. Had problems with the RAM. They sent me four new sticks, which also generated errors. Singled out four sticks (from the eight I now had) that didn't generate any errors. Discovered by coincident a new RAM error last week (this time no BSOD). Contacted the company. According to them there have been issues with a bad stock from last summer so I got two tested 8 GB sticks sent to me. Been running Memtest86+ over the weekend. After 20 hours I got an error (see attached photo). The test has now been running for 37 hours but so far only this one error. I contacted the company where I bought the computer. They wrote back: I wouldn't worry about hat one fail. We have had similar situations here whereby it passes numerous times but then fails once. We think it's an issue with memtest, after all memory is faulty or it isn't so you can't really have it pass a few times, fail the next time around and then pass again! Please trust me on this and continue with the memory we sent you and if your problems continue we'll look at getting it replaced again. I gather from other forum posts that many people do not accept a single error. What could this single error signify, faulty RAM or a glitch in the MEMTEST program (or other)? Update: From the helpful comments below I conclude that an occasional (and rare) "random" error could occur and be acceptable, but repeated errors at the same address would indicate malfunction. Memtest has now run for 45 hours and I still have only one error. For everyone's information, I will keep running the test. In less than two days I am going away for a month. I will most likely leave Memtest running. As I do not have a UPS there is a risk that a power outage will ruin the experiment. The computer is a desktop so I cannot bring it with me (which would curiously have exposed it to more cosmic rays as I will be flying ;)).

  Read the article

• Clamdscan scans file in 0 seconds

  - by SupaCoco

  I have to run clamav on large files. I was wondering which command was the fastest between clamscan and clamdscan. But it seems that clamdscan is not working properly: it scans file larger than 1 GB. Could you guys help me find why the heck clamdscan isn't working ? Between clamscan and clamdscan which one is less resource consuming ? I run ClamAV 0.97.8/18037 on Ubuntu 12.04.3 LTS. Please find below the execution result of both commands: clamscan myfile.zip ----------- SCAN SUMMARY ----------- Known viruses: 2864504 Engine version: 0.97.8 Scanned directories: 0 Scanned files: 1 Infected files: 0 Data scanned: 0.00 MB Data read: 1024.16 MB (ratio 0.00:1) Time: 9.145 sec (0 m 9 s) clamdscan myfile.zip /home/ubuntu/workspace/benchmark/myfile.zip: OK ----------- SCAN SUMMARY ----------- Infected files: 0 Time: 0.000 sec (0 m 0 s) And here are the clamav log file: Wed Oct 30 10:26:32 2013 -> Received POLLIN|POLLHUP on fd 4 Wed Oct 30 10:26:32 2013 -> Got new connection, FD 9 Wed Oct 30 10:26:32 2013 -> Received POLLIN|POLLHUP on fd 5 Wed Oct 30 10:26:32 2013 -> fds_poll_recv: timeout after 5 seconds Wed Oct 30 10:26:32 2013 -> Received POLLIN|POLLHUP on fd 9 Wed Oct 30 10:26:32 2013 -> got command CONTSCAN /home/ubuntu/workspace/benchmark/myfile.zip (51, 7), argument: /home/ubuntu/workspace/benchmark/myfile.zip Wed Oct 30 10:26:32 2013 -> mode -> MODE_WAITREPLY Wed Oct 30 10:26:32 2013 -> Breaking command loop, mode is no longer MODE_COMMAND Wed Oct 30 10:26:32 2013 -> Consumed entire command Wed Oct 30 10:26:32 2013 -> Number of file descriptors polled: 1 fds Wed Oct 30 10:26:32 2013 -> fds_poll_recv: timeout after 3600 seconds Wed Oct 30 10:26:32 2013 -> THRMGR: queue (single) crossed low threshold -> signaling Wed Oct 30 10:26:32 2013 -> THRMGR: queue (bulk) crossed low threshold -> signaling Wed Oct 30 10:26:32 2013 -> /home/ubuntu/workspace/benchmark/myfile.zip: OK Wed Oct 30 10:26:32 2013 -> Finished scanthread Wed Oct 30 10:26:32 2013 -> Scanthread: connection shut down (FD 9) Wed Oct 30 10:26:32 2013 -> THRMGR: queue (single) crossed low threshold -> signaling Wed Oct 30 10:26:32 2013 -> THRMGR: queue (bulk) crossed low threshold -> signaling

  Read the article

• How to make Windows 7 use the internet connection that I specify

  - by user138957

  I have a LAN adapter and a USB wireless internet connection. When both connected windows 7 always uses the USB. I tried changing the metric values but no luck. Let me explains the steps I took. Currently automatic metric on all adapters. LAN connected. ipconfig shows that it is connected to the correct ip/dns/gateway etc. IPv4 Route table shows Metric 24 Then connected USB. ipconfig shows USB connectivity then LAN in that order. Internet is now through USB. IPv4 Route table shows Metric 4249 for LAN and USB is 41. Gateway for USB shows "on-link". netstat -rn shows USBDEVICE on top. Changed LAN metric to 5 and now the route table shows LAN as 9 (not sure why it added 4) and USB as 41. netstat shows LAN then USB. ipconfig shows LAN then USB. But still connection is through USB. How do I know? Task manager shows utilization only through USB as well as speed is showing around 1mbps rather than LANs 10mbps. How can I get win7 use LAN while USB is connected. I am just trying to use USB as a backup just in case I lose LAN connection. Please help!! I thought i will make USB metric manually to say 10. But it says I have to reconnect for it to be effective. Currently USB still shows below LAN and still has 9 and 41 in the table. Disconnected USB. Table shows LAN metric as 24 (Not sure why it got changed from 9 and setting got reverted by to automatic) Reconnected USB. Now in the setting still shows 10 and the route table shows 11 for USB and LAN shows 4249 (settings shows 4245, 4 less)) For some reason restarting USB is resetting LAN setting when reconnected. Thanks

  Read the article

• System won't boot: Gigabyte HD 7790 1GB OC GPU issue or Corsair VS550 PSU issue?

  - by MGOwen

  Installed a new GPU, and PC won't boot. Turn it on and: No monitor signal at all (tried HDMI and VGA via DVI, on 2 working monitors). CPU and GPU fans DO spin, but No system beeps, no sounds from drives (they might make a small noise in the first 1 second or so, but there's definitely no OS loading or anything like that) If hit "power off" button it turns off immediately (no holding down for 3 seconds like usual) If I put my old HD 5670 GPU back in, everything works fine. But (plot twist!) card is not totally dead. My friend put it in his PC, and it works fine (he even played a game for 15 minutes, no issues). He has a Corsair TX850 850W and a Gigabyte MB. So my main theory is: the GPU isn't getting enough power from the PSU. But is it: Bad PSU? Seems unlikely, since it works fine with the other GPU. Also, the PSU Is brand new and 550W (single 42A/504W 12V rail). Overkill for this GPU. Corsair is a decent brand, but maybe just mine is faulty? Bad GPU? Could it be drawing more power than it should be, somehow, or something? Supposedly HD 7790 needs only 21A/75W on the 12v rail, though this one is factory overclocked a bit... but should that triple the power requirement? Something else? Could there be a motherboard incompatibility somehow? Both MB and GPU are less than a year old and PCI Express 3.0 x16. Things I've tried: Re-seating the video card Testing PC with old GPU (works fine, same PCIe slot). Checked AMD's stated amp/watt requirements of a 7790 and my PSU (see above). My PSU can output twice the amps (single rail) and 5x the Wattage a 7790 needs. Here are the full specs: Gigabyte HD 7790 1GB OC GPU Corsair VS550 550W PSU 4GB RAM AsRock H61M U3S3 motherboard i3-2100 500GB SATA HDD (2007-ish) blu-ray drive (new) PCI 802.11g card Edit: Motherboard BIOS Update seems to have fixed it. (If anyone has same problem and it doesn't work, comment here).

  Read the article

• A gigabit network interface is CPU-limited to 25MB/s. How can I maximize the throughput?

  - by netvope

  I have a Acer Aspire R1600-U910H with a nForce gigabit network adapter. The maximum TCP throughput of it is about 25MB/s, and apparently it is limited by the single core Intel Atom 230; when the maximum throughput is reached, the CPU usage is about 50%-60%, which corresponds to full utilization considering this is a Hyper-threading enabled CPU. The same problem occurs on both Windows XP and on Ubuntu 8.04. On Windows, I have installed the latest nForce chipset driver, disabled power saving features, and enabled checksum offload. On Linux, the default driver has checksum offload enabled. There is no Linux driver available on Nvidia's website. ethtool -k eth0 shows that checksum offload is enabled: Offload parameters for eth0: rx-checksumming: on tx-checksumming: on scatter-gather: on tcp segmentation offload: on udp fragmentation offload: off generic segmentation offload: off The following is the output of powertop when the network is idle: Wakeups-from-idle per second : 61.9 interval: 10.0s no ACPI power usage estimate available Top causes for wakeups: 90.9% (101.3) <interrupt> : eth0 4.5% ( 5.0) iftop : schedule_timeout (process_timeout) 1.8% ( 2.0) <kernel core> : clocksource_register (clocksource_watchdog) 0.9% ( 1.0) dhcdbd : schedule_timeout (process_timeout) 0.5% ( 0.6) <kernel core> : neigh_table_init_no_netlink (neigh_periodic_timer) And when the maximum throughput of about 25MB/s is reached: Wakeups-from-idle per second : 11175.5 interval: 10.0s no ACPI power usage estimate available Top causes for wakeups: 99.9% (22097.4) <interrupt> : eth0 0.0% ( 5.0) iftop : schedule_timeout (process_timeout) 0.0% ( 2.0) <kernel core> : clocksource_register (clocksource_watchdog) 0.0% ( 1.0) dhcdbd : schedule_timeout (process_timeout) 0.0% ( 0.6) <kernel core> : neigh_table_init_no_netlink (neigh_periodic_timer) Notice the 20000 interrupts per second. Could this be the cause for the high CPU usage and low throughput? If so, how can I improve the situation? As a reference, the other computers in the network can usually transfer at 50+MB/s without problems. A computer with a Core 2 CPU generates only 5000 interrupts per second when it's transferring at 110MB/s. The number of interrupts is about 20 times less than the Atom system (if interrupts scale linearly with throughput.) And a minor question: How can I find out what is the driver in use for eth0?

  Read the article

• Recover strategy single bad sector in moricon

  - by Damon

  This week, my harddisk made me an early christmas present in the form of a single defect sector. To make up for the puny size of the present, it chose a sector inside moricons.dll for that. This means that now the system takes about 5 minutes to boot before Windows gives up and moves on, and there's 2 dozen scary "critical failure" entries in the system log after every boot, which is annoying. OK, admittedly, I shouldn't complain, it could be worse, the bad sector could be in ntldr... SMART info more or less indicates (for what SMART can indicate anyway) that the drive is mostly OK. Soft Read Error Rate has a score of 96, and Current Pending Sector Count has a raw value of 8, which translates to a score of 100. Acronis DriveMonitor makes this an issue (lowering the overall rating to 75%), HDD Health calls it "excellent", giving an overall rating of 95% (which is what this harddisk from day one). No single score is below 95 (power on hours and spin up count), and most are 100 anyway. Well, whatever, I've seen drives with perfect SMART values fail from one second to the other, and drives with moderate values work for years. So, I'm inclined not to put too much weight into that overall. TL;DR Now... to the problem: I don't feel like trashing the disk just yet (that's planned with a new OS install upgrading to Win7 early next year, independently of this issue), but in the mean time, I would still like to have a smoothly running system again. Therefore, I feel tempted to tamper with it, but before I render my system entirely unusable (since I've never done this before), I'd like to verify that my planned procedere is likely to suceed in having a working system again: Copy moricons.dl_ from the Windows install disk, rename it to moricons.zip, and unzip it. This gives an intact 5.1.2600.2180 version (the broken one is 5.1.2600.5512 - but I guess this makes not much of a difference, since it's an icon-only DLL, and an outdated copy should work better than one that can't be read) Run chkdsk /r /f` which will "repair" the file (i.e. delete the file without asking, tell the drive to remap the sector, and toss some unreadable junk into a file with a hexadecimal number) Hopefully Windows still boots after this (is that a reasonable expectation, or do I need to have something like BartPE ready? -- but then again, what's that good for in case chkdsk has nuked the entire file system...) Delete the junk file generated by chkdsk, copy the new DLL to %windir%\system32 Reboot. Pray. Maybe I just shouldn't touch anything, since it still kind of works... if annoying, but it works. Unsure... But, is there anything fundamentally wrong with the planned approach? Is this a sensible approach at all?

  Read the article

• What is the probable failure - no BSOD, no event log, monitors sleeping, force reboot required

  - by Tyler

  Every 3 to 15 days, my PC freezes. This typically happens when the computer is idle, I'm coming home from work, back from vacation, etc. It's never happened while using my computer. The monitors are in power save mode The Caps Lock light on the (wireless) keyboard doesn't work Ctrl-alt-del has no effect, mouse (wireless) has no effect The hardware reset button and single press of power putton have no effect Computer does not appear on the network No BSOD, no memory dump Event logs have no errors or indications of problems near the time of crash. Only messages after reboot indicating that there was a reboot without a clean shutdown. Windows is set to never put the computer to sleep (just the display) Here are the vital stats of the build: OS Windows 8 Pro 64-bit CPU Intel i5-2400 Mobo Intel BOXDP67DE Micro ATX GPU MSI N460GTX Cyclone768D5/OC RAM CORSAIR XMS3 8GB (2 x 4GB) CMX8GX3M2A1333C9 PSU SeaSonic X Series X650 Gold System Drive Samsung 840 Pro 256 GB SSD Data Drive 2 x Western Digital WD20EARS 2TB in hardware RAID 1 Optical Lite-On DVD burner IHAS424-98 And here is the story of how the problem developed and what I've done to diagnose: January 2011, system built with Windows 7 64-bit, runs great. March 2011, Intel replaced the mobo because of the bad sata controllers. October 2012, upgrade to Windows 8 (problems start shortly after). January 2013, system freezes and causes network to fail for the whole house. Unplug the network cable and other devices and PCs can use the internet. Plug it back in, internet goes away for everyone. Reboot and everything is fine. March 2013, install Intel Gigabit CT PCI-E NIC, disable mobo nic in bios. Network strangeness goes away. Freezes are less frequent. Memtest shows no problems (20 passes). Early June 2013, replace Antec PSU with SeaSonic PSU. Mid June 2013, replace OCZ Vertex 2 SSD with Samsung SSD. Late June 2013, get frustrated and hope the community has some good ideas (I'm running out of budget to replace parts). My next plan of attack is setting "Turn off display" to Never and using a screen saver to see how that reacts on the next freeze. It makes me sad to waste power for up to 15 days though. Has anyone out there seen a problem like this? Any ideas on what kind of malfunction would act this way? Ideas of other diagnostic steps to take?

  Read the article

• iotop for Linux kernel 2.6.18

  - by Lightsauce

  So it has to come to my attention that iotop isn't availalbe for 2.6.18 since it's less than 2.6.20 and requires Python 2.6+. I've done some research and came across this article: http://lserinol.blogspot.com/2009/09/io-usage-per-process-on-linux.html According to this, if these process have io stats in /proc/pid#/io (where pid# is the process #) it's doable regardless of the kernel version. So, in reality, I could upgrade Python to 2.6 and test out iotop. However, my flavor of Linux, CentOS release 5.5 (Final), only supports Python 2.4.3-44.el5 currently. If I were to do uninstall from yum, it doesn't look so pretty. It ends up wanting to uninstall 235 packages, most of which are very important! I read in one place, online (I forget the URL from yesterday), that you can install Python 2.6+ parallel to this one, and have the rpm install for iotop use that. Well, I didn't choose that route. I figured, what the heck, lets write iotop (not copying it, but reverse engineering it without actually looking at it's code/it in use) in bash. I thought it would just grab the /proc/pid#/io file and parse stats. So I wrote a script to grab the top 10 rchar, wchar, read_bytes, and write_bytes by collecting all these stats from all the /proc/pid#/io files, sorting them by each metric, then grabbing the top 10 highest values. The conclusion, the data seems completely useless. Does anybody know any resources for advanced Linux where I can figure out how to take these /proc/pid#/ directories and figure out what the heck they are doing with io on the disk? My main goal is to figure out what exactly is causing high load on my disk. I just know it's on the / partition (/dev/sda2 in this case), and I'm not really sure how to narrow it down without the help of iotop. If I run iostat to grab metrics for 1 minute, every second, the first result it gives me shows a high 'kB_read/s', so that makes me think, it's reading mostly. However, if I watch the update it gives me every second, it's actually just showing values for kB_wrtn/s. This makes me think the initial value iostat gives me is misleading.

  Read the article

• What Sort of Server Setup Am I Likely to Need? - School A/V streaming

  - by DeathMagus

  My prior experience with servers has generally been limited to home file-sharing servers, low-traffic web-servers, and the like. This leaves me with the technical knowledge of how to set up a system, but little experience in terms of scaling said system. My current project, however, has me as the technical lead in setting up a school for online audio and video streaming. The difficulty I'm running into is that I don't quite have the experience to guess what they'll need, and they don't have the experience to tell me - so I've tried to ask as many pertinent questions about what they want to do with their server, and here's what I found out: About 1000 simultaneous users, and hoping to expand (possibly significantly) Both video and audio streaming, at obviously the highest quality possible Support for both live and playlist-based streaming. Probably only one channel, but as it's an educational opportunity, I imagine letting them have a few more wouldn't hurt. No word on whether they're locked into Windows or whether Linux is acceptable. Approximate budget - $7000. It may actually be about $2k less than this, because of a mishap with another technology firm (they ordered a $7000 DV tape deck for some reason, and now the company wants them to pay a 30% restocking fee). The tentative decisions I've already made: I'm planning on using Icecast 2 for my streaming server, fed by VLC Shoutcast encoding. Since the school already has a DMZ set up, I plan on placing the Icecast server in there, and feeding it through their intranet from a simple workstation computer in their studios. This system isn't in any way mission critical - it's an education tool (they're a media magnet school), so I figure redundancy is not worthwhile to them from a cost:benefit perspective. What I don't know is this: How powerful of a server will I need? What is likely to be my major throttle - bandwidth? How can I mitigate that? Will I need anything special for the encoding workstation other than professional video and audio capture cards and a copy of VLC? Are there any other considerations that I'm simply missing? Thanks a lot for any help - if there's more information you need, let me know and I'll tell you all I can.

  Read the article

• cd Command Linux and Mystery Flags

  - by Jason R. Mick

  Platform: CentOS 6.2 Shell:tcsh I'm playing around with cd for a BASH script, and noticed the wondrous cd - option, but was left with many questions... Why the cd -? Isn't this redundant with cd ..? EDIT [As FatalError points out, these two commands don't do the same things... so the answer is "no"] Can you delve farther back into your history with - flag, a la in a browser? e.g. When I type cd -, it takes me to my previous directory, but then if I enter that command again, it takes me to the directory I just came from, creating a sort of loop. Is a shorthand for going back multiple levels supported?EDITI realize I can go back with cd .., but was hoping this could be a gateway to a less verbose deep back, e.g. cd -3 vs. cd ../../../ ... hopefully that clarifies what I'm asking....EDIT2As to the current feedback, while .. is a special directory, I don't see a reason why the built-in cd to the terminal couldn't use a shorthand for ../../ ... ../ e.g. cd ..5 or why the built-in also couldn't have a history (a la auto pushd/popd) that could be turned on and used like cd -3. I get that this could be somewhat of security/privacy risk, but I don't see how it's any worst than storing a command history, which most shells/terminals do. The manpage for cd, accessible via man cd and help cd (it's the same for either command), only lists -L and -P flags. However when I type in cd --help it outputs Usage: cd [-plvn][-|<dir>].. Am I right in assuming the other flags and the - (back) option are nonstandard? What are the -n and -v flags for? Both seem to take me back to my home directory, that's all I've been able to figure out via experimentation. A quick read on web resources [1][2] offered just the same sort of info that the man page did and didn't answer my questions. Note: The second Linux-centric resource above claimed cd only had two options (obviously not true in current CentOS) hence my assumption that this functionality could be non-standard.

  Read the article

• MongoDB and datasets that don't fit in RAM no matter how hard you shove

  - by sysadmin1138

  This is very system dependent, but chances are near certain we'll scale past some arbitrary cliff and get into Real Trouble. I'm curious what kind of rules-of-thumb exist for a good RAM to Disk-space ratio. We're planning our next round of systems, and need to make some choices regarding RAM, SSDs, and how much of each the new nodes will get. But now for some performance details! During normal workflow of a single project-run, MongoDB is hit with a very high percentage of writes (70-80%). Once the second stage of the processing pipeline hits, it's extremely high read as it needs to deduplicate records identified in the first half of processing. This is the workflow for which "keep your working set in RAM" is made for, and we're designing around that assumption. The entire dataset is continually hit with random queries from end-user derived sources; though the frequency is irregular, the size is usually pretty small (groups of 10 documents). Since this is user-facing, the replies need to be under the "bored-now" threshold of 3 seconds. This access pattern is much less likely to be in cache, so will be very likely to incur disk hits. A secondary processing workflow is high read of previous processing runs that may be days, weeks, or even months old, and is run infrequently but still needs to be zippy. Up to 100% of the documents in the previous processing run will be accessed. No amount of cache-warming can help with this, I suspect. Finished document sizes vary widely, but the median size is about 8K. The high-read portion of the normal project processing strongly suggests the use of Replicas to help distribute the Read traffic. I have read elsewhere that a 1:10 RAM-GB to HD-GB is a good rule-of-thumb for slow disks, As we are seriously considering using much faster SSDs, I'd like to know if there is a similar rule of thumb for fast disks. I know we're using Mongo in a way where cache-everything really isn't going to fly, which is why I'm looking at ways to engineer a system that can survive such usage. The entire dataset will likely be most of a TB within half a year and keep growing.

  Read the article

• How to unmangle PDF format into a usable text or spreadsheet document?

  - by Chuck

  Upon requesting some daily/hourly sales data from a coworker who is responsible for such requests, I was given a series of PDF files. The point of sale program that is used, for some reason, answers requests for this type of information in the form of PDF files. The issue: The PDF files look to be in a format that should easily be copy and pasted into a spreadsheet. There are three columns that look to be neatly organized across two pages. When copy/pasting the first page, all three columns from the PDF's first page are dumped into a single column consisting of the Date followed by the Hours for the transactions on that day. The end of this Date/Time information is followed by all of the Total Sales values that should be attached a Date and Time of the transaction. (NOTE: There are no duplicated Dates in the Date column, ie, Multiple transactions for a day only have one yyyy/mm/dd listed for the first row but not the following rows.) While it was a huge pain, it was possible to, in about four or five steps, get the single column of data broken out into three columns that matched the PDF. The second page of the PDF file, when attempting to copy/paste into a spreadsheet, creates a single column with the first third of the cells being the Dates from the PDF, the second third of the cells being the Hours of the transactions and the final third of the cells being filled with the Total Sales. After the copy/paste there is no way to figure out which Hours belong to which Dates or Total Sales due to the lack of the duplicated Dates in the Date column as mentioned above. My PDF-fu is next to non-existent. I've just now started to work with PDF editors and some www.convertmyPDFforfree.com websites, so far, with absolutely nothing remotely coming anywhere near usable output. (Both methods have so far done nothing but product blank documents.) Before I go back and pester my co-worker into figuring out a way to create a report in some other format than PDF, is there any method by which to take the data that looks to be formatted correctly in a PDF and copy/paste it into a spreadsheet that will look the same? I appreciate any help that can be made available. The sales data isn't so sensitive that I couldn't part with a bit to let somebody actually see what it is that needs to be dealt with, just let me know. The PDF's are less than 100kb each so sending them shouldn't be a burden to any interested party.

  Read the article

• How to format and where to put the SPF TXT record?

  - by YellowSquirrel

  EDIT I think I more or less understand the syntax and, anyway, Google is giving, in the link below, the syntax needed. My question is really where to put that stuff. Should I quote every field? The whole line? :) I've set up Google apps for my domain: I've registered the domain with Google by adding the CNAME Google asked and I've apparently succesfully setup the MX Google mail servers. So far I haven't yet a dedicated server: I'm just having a domain at a registrar. Now I want to activate SPF and I'm confused. In the following short webpage: http://www.google.com/support/a/bin/answer.py?answer=178723 it is written that I must add a TXT record containing: v=spf1 include:_spf.google.com ~all Where should I enter this? Should this go in the zone (?) file, like I did for the CNAME and the MX records? So far I have something like this: @ 10800 IN A 217.42.42.42 @ 10800 IN MX 5 ASPMX3.GOOGLEMAIL.COM. @ 10800 IN MX 5 ASPMX2.GOOGLEMAIL.COM. @ 10800 IN MX 3 ALT2.ASPMX.L.GOOGLE.COM. @ 10800 IN MX 3 ALT1.ASPMX.L.GOOGLE.COM. @ 10800 IN MX 1 ASPMX.L.GOOGLE.COM. google8a70835987f31e34 10800 IN CNAME google.com. Does adding the SPF TXT record mean I should literally have something like that: @ 10800 IN A 217.42.42.42 @ 10800 IN MX 5 ASPMX3.GOOGLEMAIL.COM. @ 10800 IN MX 5 ASPMX2.GOOGLEMAIL.COM. @ 3600 IN TXT "v=spf1 include:_spf.google.com ~all" @ 10800 IN MX 3 ALT2.ASPMX.L.GOOGLE.COM. @ 10800 IN MX 3 ALT1.ASPMX.L.GOOGLE.COM. @ 10800 IN MX 1 ASPMX.L.GOOGLE.COM. google8a70835987f31e34 10800 IN CNAME google.com. I made that one up and included right in the middle to show how confused I am. What I'd like to know is the exact syntax and where/how I should put this TXT record.

  Read the article

• Windows 2003 Server Caching

  - by pablomedok

  We're experiencing almost everyday table index corruption on Windows Server 2003. We are running an old application which uses DBF/CDX tables. Everything was fine for ages, but 6 months after we've installed Advantage Database Server (which allows access to some tables to our website) we started to get index corruption problems. And we don't know whom to blame. We've tried to exclude all possible causes of this corruption. Now all users work in terminal mode - so no network problems can cause that, OpLocks also can't be a reason. We changed hardware, network cards, switches, reainstalled Server and even moved to new dedicated server. The only thing we can't exclude is ADS - because it should be working. Is that possible that local read/write caching that causes that problem? E.g. one user or process uses cached data, later another user/process changes it, and later the first user changes it again without knowing about the first change. Is it possible theoretically? Is it possible that this problem is caused by imporper file server or caching settings? Is it possible that normal users use non-cached data and ADS is using cached data? Or vice versa? Is it possible that each terminal user has its own cache? Or maybe the problem is about RAID caching somehow interfering with Windows Server caching? Or maybe there are some special settings for Windows Server for working with DBF tables that are being written simultaneously by several terminal users? Maybe there is a way to turn off caching for some certain files to check it? Sometimes we get index crash twice a day, sometimes everything is fine for 5 days in a row. Today only one user was working in the evening with the database (usually there are 30-50 users are working simultaneously on working hours). So it's almost zero load on server. , Syncronization with website is performed every 5 minutes during work hours and every 15 minutes in the evening and on weekend. We've done file access auditing and it shows that during website syncroniztions ADS server opens the table and index files for ReadEA and WriteEA though it performs only SELECT queries. ADS does UPDATE/INSERT queries but less freqently - not during regular synchronizations, but only when an order is placed by website visitor). Please help me. We are struggling with this problem for almost a year and still can't find any pattern or any clue about this problem. Here is my previous qestion about this issue on DBA: http://dba.stackexchange.com/questions/8646/foxpro-dbf-index-corruption

  Read the article

• Melting Laptop Power Supply Tip

  - by AlReece45

  Several (6-7) months ago, my laptop power supply cord got a cut in it and stopped working. Having gotten cheap (and short) power supplies in the past, I decided to buy 2 brand new ones from the manufacturer (ASUS). Now, I used my laptop a little less than usual between February and March. During that time I noticed a few times that the power supply, even though plugged in, did not provide power. Often the computer would just off on me. I figured it was just that one power supply being bad. I had left the alternate at my parent's house in another state and asked them to ship it to me. Now, at work the other day I wanted to get a file off the of hard disk. So I booted it up, knowing that it had a low battery, plugged it in. During the first 2 minutes of use, I was told that the battery was low and I should plug it in. I unplugged it, inspected the end (Being plugged in, this was suspicious), and decided I shouldn't plug it back in-- the plastic on the tip was melting from the heat of the metal on the tip. The computer had simply booted up and I had the file-manager open. It had not been on for more than 10 hours. Now I know that computers tend to get pretty hot. However, the melting point of plastic is usually above 200C.. so that's much hotter than the computer should be generating. I went and bought a THIRD power supply. This time a universal one from Best Buy (it was very fast to buy and test). I tried it out on the computer and it's tip is melting as well. My older laptop that uses the universal power supply uses it perfectly (has been about a week and a part of use now). I have tried using the computer without the battery, with the same effect. Obviously, this is not a problem with the power supply. My room mate and I being trained computer techs were contemplating taking the computer apart and desoldering and resoldering on the power tip. (The computer is about 6 months out of its 2-year warranty). We're hoping that will correct the issue as I would prefer to devote my money on a Good Desktop rather than yet ANOTHER $1200+ laptop. Is there any thing I'm missing here that might cause the the tip on the power unit to melt?

  Read the article

• Slow WLAN file transfer between server and tablet

  - by user266985

  My file server is running Ubuntu 12.04 and I'm sharing files from it over samba. It is connected via gigabit ethernet. My desktop, running Windows 8.1, is also connected via gigabit ethernet. I can transfer files between the two and completely saturate that gigabit pipe. However, I just got a Surface Pro 2, and I'm trying to stream HD movies from my server to the device over WiFi. For some reason, I can't break much past 1.5MB/s transferring files over the network. I've tried streaming through XBMC and a standard file copy; no difference. To add the confusion, if I connect to my guest network and then use my VPN server (installed on the router) to access the file server, I get around 3.2MB/s. I've been running diagnostics to determine the root and I think I've found it but I have no idea what is causing it or how to fix it. Router: Asus RT-N66U Surface Pro 2 Network Card: Marvell Avastar 350N (Driver 19/09/2013 v14.69.24044.150) InSSIDer: Link Score: 100 Co-Channels: 0 Overlapping: 0 5GHz Network Channel: 48+44 iperf File Server as Server; Surface Pro 2 as Client - TCP Performance: Acceptable ------------------------------------------------------------ Server listening on TCP port 5001 TCP window size: 85.3 KByte (default) ------------------------------------------------------------ [ 4] local 192.168.0.90 port 5001 connected with 192.168.0.56 port 57367 [ ID] Interval Transfer Bandwidth [ 4] 0.0- 1.0 sec 10.1 MBytes 84.7 Mbits/sec [ 4] 1.0- 2.0 sec 10.4 MBytes 87.6 Mbits/sec [ 4] 2.0- 3.0 sec 10.6 MBytes 88.8 Mbits/sec [ 4] 3.0- 4.0 sec 10.7 MBytes 89.5 Mbits/sec [ 4] 4.0- 5.0 sec 10.1 MBytes 84.4 Mbits/sec [ 4] 5.0- 6.0 sec 10.2 MBytes 85.8 Mbits/sec [ 4] 6.0- 7.0 sec 7.04 MBytes 59.1 Mbits/sec [ 4] 7.0- 8.0 sec 10.8 MBytes 90.2 Mbits/sec [ 4] 8.0- 9.0 sec 10.6 MBytes 89.1 Mbits/sec [ 4] 9.0-10.0 sec 8.62 MBytes 72.3 Mbits/sec [ 4] 0.0-10.0 sec 99.2 MBytes 83.1 Mbits/sec iperf Surface Pro 2 as Server, File Server as Client Performance: Poor ------------------------------------------------------------ Client connecting to 192.168.0.56, TCP port 5001 TCP window size: 22.9 KByte (default) ------------------------------------------------------------ [ 3] local 192.168.0.90 port 40233 connected with 192.168.0.56 port 5001 [ ID] Interval Transfer Bandwidth [ 3] 0.0- 1.0 sec 1.50 MBytes 12.6 Mbits/sec [ 3] 1.0- 2.0 sec 1.50 MBytes 12.6 Mbits/sec [ 3] 2.0- 3.0 sec 1.50 MBytes 12.6 Mbits/sec [ 3] 3.0- 4.0 sec 1.25 MBytes 10.5 Mbits/sec [ 3] 4.0- 5.0 sec 1.62 MBytes 13.6 Mbits/sec [ 3] 5.0- 6.0 sec 1.50 MBytes 12.6 Mbits/sec [ 3] 6.0- 7.0 sec 1.38 MBytes 11.5 Mbits/sec [ 3] 7.0- 8.0 sec 1.50 MBytes 12.6 Mbits/sec [ 3] 8.0- 9.0 sec 1.50 MBytes 12.6 Mbits/sec [ 3] 9.0-10.0 sec 1.62 MBytes 13.6 Mbits/sec [ 3] 0.0-10.1 sec 15.0 MBytes 12.4 Mbits/sec For some reason, it gets capped and I haven't got a clue why. Any suggestions? Edit: My link speed is reported as 270Mbps by Windows. I'm less than two metres from the router with a clear line of sight.

  Read the article

• Will spreading your servers load not just consume more recourses

  - by Saif Bechan

  I am running a heavy real-time updating website. The amount of recourses needed per user are quite high, ill give you an example. Setup Every visit The application is php/mysql so on every visit static and dynamic content is loaded. Recourses: apache,php,mysql Every second (no more than a second will just be too long) The website needs to be updated real-time so every second there is an ajax call thats updates the website. Recourses: jQuery,apache,php,mysql Avarage spending for single user (spending one minute and visited 3 pages) Apache: +/- 63 requests / responsess serving static and dynamic content (img,css,js,html) php: +/- 63 requests / responses mysql: +/- 63 requests / responses jquery: +/- 60 requests / responses Optimization I want to optimize this process, but I think that maybe it would be just the same in the end. Before implementing and testing (which will take weeks) I wanted to have some second opinions from you guys. Every visit I want to start off with having nginx in the front and work as a proxy to deliver the static content. Recources: Dynamic: apache,php,mysql Static: nginx This will spread the load on apache a lot. Every Second For the script that loads every second I want to set up Node.js server side javascript with nginx in te front. I want to set it up that jquery makes a request ones a minute, and node.js streams the data to the client every second. Recources: jQuery,nginx,node.js,mysql Avarage spending for single user (spending one minute and visited 3 pages) Nginx: 4 requests / responsess serving mostly static conetent(img,css,js) Apache: 3 requests only the pages php: 3 requests only the pages node.js: 1 request / 60 responses jquery: 1 request / 60 responses mysql: 63 requests / responses Optimization As you can see in the optimisation the load from Apache and PHP are lifted and places on nginx and node.js. These are known for there light footprint and good performance. But I am having my doubts, because there are still 2 programs extra loaded in the memory and they consume cpu. So it it better to have less programs that do the job, or more. Before I am going to spend a lot of time setting this up I would like to know if it will be worth the while.

  Read the article

• How to move partition with Users to a new SATA controller?

  - by Al Kepp

  Our current situation: X79 chipset. Windows 7 installed on SATA SSD running on Marvell controller. C:\Users contains just Public and computer-name folders, all the other users are created in E:\Users. That partition is on two HDD's running on an Intel RAID controller. (The motherboard has got two SATA/RAID onboard controllers.) The goal is: Without reinstallation, I want to move SSD to a standard SATA controller. Then I want to get rid of RAID1, and move one HDD to the same internal Intel SATA controller and the current E:\Users move to that new place. I want it to stay as E:\users, but I need to reinstall the HDD to let it work in SATA mode without RAID. So I face several problems. I am sure all are solvable with free software utilities, but I don't know how exactly to do it. I can see the particular problems: I have got all users at E:\Users. When I turn off that E:\ disk, I won't be able to login to Windows. I need at least one admin account to be placed back at C:\users. The current C: runs on standard 120 GB SSD, but it is connected to a Marvell SATA/RAID controller. I am affraid the Windows won't let me put it to Intel SATA controller due to hardware/licence check, and I won't be able to use standard W7 recovery disk either, because there probably isn't marvel SATA/RAID driver on it. I haven't tried anything yet, because I am affraid I can end up with computer not working at all. (I want to move it to a standard ICH10 Intel SATA controller to let us have no problems in future with it. I think it is not very safe when we use any nonstandard hardware to boot the computer.) I need to somehow backup current E:\ disk and restore it to a new E:. I hope this will be the easy part (as long as the admin account will reside on C:). The E: RAID array is very large, but it is almost empty (less than 100 GB of data.) So I can make the partition smaller so it can easily fit to a single SATA HDD.

  Read the article

• How does an NTP host switch among the various modes?

  - by James A. Rosen

  The NTPv3 RFC describes five operating modes: Symmetric Active (1): A host operating in this mode sends periodic messages regardless of the reachability state or stratum of its peer. By operating in this mode the host announces its willingness to synchronize and be synchronized by the peer. Symmetric Passive (2): This type of association is ordinarily created upon arrival of a message from a peer operating in the symmetric active mode and persists only as long as the peer is reachable and operating at a stratum level less than or equal to the host; otherwise, the association is dissolved. However, the association will always persist until at least one message has been sent in reply. By operating in this mode the host announces its willingness to synchronize and be synchronized by the peer. Client (3): A host operating in this mode sends periodic messages regardless of the reachability state or stratum of its peer. By operating in this mode the host, usually a LAN workstation, announces its willingness to be synchronized by, but not to synchronize the peer. Server (4): This type of association is ordinarily created upon arrival of a client request message and exists only in order to reply to that request, after which the association is dissolved. By operating in this mode the host, usually a LAN time server, announces its willingness to synchronize, but not to be synchronized by the peer. Broadcast (5): A host operating in this mode sends periodic messages regardless of the reachability state or stratum of the peers. By operating in this mode the host, usually a LAN time server operating on a high-speed broadcast medium, announces its willingness to synchronize all of the peers, but not to be synchronized by any of them. It seems to me, though, that any host except a leaf node would probably be in several modes. For example, I might have a local area network with three NTP servers, each in Symmetric Active (1) mode with respect to one another. They would also each be clients (3) of one of the many public stratum two time servers. Lastly, they would all server as servers (4) to the many local clients. Is the point that they're only in a given mode for a moment during the synchronization? If so, how does a host know to switch? I'm only looking for enough depth here to discuss the issue in an educated manner, not to write a custom time server.

  Read the article

< Previous Page | 278 279 280 281 282 283 284 285 286 287 288 289  | Next Page >