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  • Should I Return My iPhone?

    - by Daniel
    got an iPhone 3G S about 20 days ago. That means I can return it no problem for the next 10 days. Should I return it, wait about 6 weeks, and get the iPhone 4.0 instead? I also put about $25 towards accessories but I could probably sell them for $15. Is it worth it not having it for those 6 weeks? Or should I just go with the free update, keep my screen protectors and case, and "survive" without the phone. What new features will come with the phone? My understanding is that most of the features will be part of the upgrade. My other option will probably be to give it back and then when they make the official announcement, buy the 3G S for maybe $99 if they drop the price that much.

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  • Dell Dimension running Fedora12 does a "Sleeping Beauty" and I am not a "handsome prince"!

    - by Jim Dobbs
    Dell Dimension 2350 with a Pentium IV processor and integrated video and network chips running Fedora12 does a "Sleeping Beauty" and I, apparently, am not am not a "handsome prince"! The system puts video and network to sleep and it will not wakeup. I have heard of this problem on laptops, but this is a tower. Any ideas or help is appreciated. I tried to ping the network card from another system and ping fails. The logs indicate that the system continues to be active. Pressing keyboard short-cut keys makes the disk light blink but neither the video or network card comes alive. Failing all else, are there any Linux commands that I could schedule in cron to pulse video and network adapters hourly that will keep them awake? Or, should I wait on Fedora13? Before this machine, I built a Dimension 2400 with Pentium IV and it had the same problem. Fedora9 on the same hardware is fine.

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  • C - circular character buffer w/ pthreads

    - by Matt
    I have a homework assignment where I have to implement a circular buffer and add and remove chars with separate threads: #include <pthread.h> #include <stdio.h> #define QSIZE 10 pthread_cond_t full,/* count == QSIZE */ empty,/* count == 0 */ ready; pthread_mutex_t m, n; /* implements critical section */ unsigned int iBuf, /* tail of circular queue */ oBuf; /* head of circular queue */ int count; /* count characters */ char buf [QSIZE]; /* the circular queue */ void Put(char s[]) {/* add "ch"; wait if full */ pthread_mutex_lock(&m); int size = sizeof(s)/sizeof(char); printf("size: %d", size); int i; for(i = 0; i < size; i++) { while (count >= QSIZE) pthread_cond_wait(&full, &m);/* is there empty slot? */ buf[iBuf] = s[i]; /* store the character */ iBuf = (iBuf+1) % QSIZE; /* increment mod QSIZE */ count++; if (count == 1) pthread_cond_signal(&empty);/* new character available */ } pthread_mutex_unlock(&m); } char Get() {/* remove "ch" from queue; wait if empty */ char ch; pthread_mutex_lock(&m); while (count <= 0) pthread_cond_wait(&empty, &m);/* is a character present? */ ch = buf[oBuf]; /* retrieve from the head of the queue */ oBuf = (oBuf+1) % QSIZE; count--; if (count == QSIZE-1) pthread_cond_signal(&full);/* signal existence of a slot */ pthread_mutex_unlock(&m); return ch; } void * p1(void *arg) { int i; for (i = 0; i < 5; i++) { Put("hella"); } } void * p2(void *arg) { int i; for (i = 0; i < 5; i++) { Put("goodby"); } } int main() { pthread_t t1, t2; void *r1, *r2; oBuf = 0; iBuf = 0; count=0; /* all slots are empty */ pthread_cond_init(&full, NULL); pthread_cond_init(&empty, NULL); pthread_mutex_init(&m, NULL); pthread_create(&t1, NULL, p1, &r1); pthread_create(&t2, NULL, p2, &r2); printf("Main"); char c; int i = 0; while (i < 55) { c = Get(); printf("%c",c); i++; } pthread_join(t1, &r1); pthread_join(t2, &r2); return 0; } I shouldn't have to change the logic much at all, the requirements are pretty specific. I think my problem lies in the Put() method. I think the first thread is going in and blocking the critical section and causing a deadlock. I was thinking I should make a scheduling attribute? Of course I could be wrong. I am pretty new to pthreads and concurrent programming, so I could really use some help spotting my error.

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  • Unnecessary Java context switches

    - by Paul Morrison
    I have a network of Java Threads (Flow-Based Programming) communicating via fixed-capacity channels - running under WindowsXP. What we expected, based on our experience with "green" threads (non-preemptive), would be that threads would switch context less often (thus reducing CPU time) if the channels were made bigger. However, we found that increasing channel size does not make any difference to the run time. What seems to be happening is that Java decides to switch threads even though channels aren't full or empty (i.e. even though a thread doesn't have to suspend), which costs CPU time for no apparent advantage. Also changing Thread priorities doesn't make any observable difference. My question is whether there is some way of persuading Java not to make unnecessary context switches, but hold off switching until it is really necessary to switch threads - is there some way of changing Java's dispatching logic? Or is it reacting to something I didn't pay attention to?! Or are there other asynchronism mechanisms, e.g. Thread factories, Runnable(s), maybe even daemons (!). The answer appears to be non-obvious, as so far none of my correspondents has come up with an answer (including most recently two CS profs). Or maybe I'm missing something that's so obvious that people can't imagine my not knowing it... I've added the send and receive code here - not very elegant, but it seems to work...;-) In case you are wondering, I thought the goLock logic in 'send' might be causing the problem, but removing it temporarily didn't make any difference. I have added the code for send and receive... public synchronized Packet receive() { if (isDrained()) { return null; } while (isEmpty()) { try { wait(); } catch (InterruptedException e) { close(); return null; } if (isDrained()) { return null; } } if (isDrained()) { return null; } if (isFull()) { notifyAll(); // notify other components waiting to send } Packet packet = array[receivePtr]; array[receivePtr] = null; receivePtr = (receivePtr + 1) % array.length; //notifyAll(); // only needed if it was full usedSlots--; packet.setOwner(receiver); if (null == packet.getContent()) { traceFuncs("Received null packet"); } else { traceFuncs("Received: " + packet.toString()); } return packet; } synchronized boolean send(final Packet packet, final OutputPort op) { sender = op.sender; if (isClosed()) { return false; } while (isFull()) { try { wait(); } catch (InterruptedException e) { indicateOneSenderClosed(); return false; } sender = op.sender; } if (isClosed()) { return false; } try { receiver.goLock.lockInterruptibly(); } catch (InterruptedException ex) { return false; } try { packet.clearOwner(); array[sendPtr] = packet; sendPtr = (sendPtr + 1) % array.length; usedSlots++; // move this to here if (receiver.getStatus() == StatusValues.DORMANT || receiver.getStatus() == StatusValues.NOT_STARTED) { receiver.activate(); // start or wake up if necessary } else { notifyAll(); // notify receiver // other components waiting to send to this connection may also get // notified, // but this is handled by while statement } sender = null; Component.network.active = true; } finally { receiver.goLock.unlock(); } return true; }

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  • How likely can my data be recovered after Windows CHKDSK performed on a degraded RAID 5 array?

    - by chrisling106
    Hello there, We have a RAID 5 setup with 3 SATA disks, #2 went down as reported on the pre-POST screen. Unfortunately, for some reason out of my control, the system was rebooted with a degraded RAID :-O Windows XP (64-bit) loaded, CHKDSK ran automatically and done its recovery! From that point onwards, the following error prompts every time even in Safe Mode: lsass.exe - The endpoint format is invalid I took those 3 disks to the data recovery expert and need to wait at least 2-4 days for results. There are 2 VMs on multiple files stored in this RAID 5 array, and there's no backup! Sorry, I just inherited the system from an ex-staff who has left the company 2 months before I joined. How likely the data can be recovered?

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  • Can you make torrents start downloading only AFTER the previous torrent has finished downloading in uTorrent?

    - by Sammy
    If I have multiple downloads I can have them all download simultaneously or pause one and let the other download and then when the 1st is done I manually pause it and have the second download, afterward I let both seed for a while. But How can I set it so that the 2nd torrent will start downloading only after the 1st has finished. And is it possible to have the 1st pause seeding after it has finished downloading. I have nothing against seeding but I want to wait till all my downloads are done before sole seeding. If these things aren't possible in uTorrent is there another client that handles these things?

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  • "Brute force attempt" on sending multiple emails

    - by bretddog
    While testing to send multiple emails, I successfully sent about 100 emails (with a 20KB pdf attachment), to the same email-address (my own), and they were all received. But on next attempt, my cPanel account was blocked, due to a "brute force attempt". Are there any special precautions I need to take when sending bulk emails? I simply looped through below code without pause for each email. What type of alert could that give on the email server, and how should I avoid it? client = New SmtpClient(smtp, Convert.ToInt32(port)) AddHandler client.SendCompleted, AddressOf OnAsyncSendComplete client.Credentials = New System.Net.NetworkCredential(usn, psw) client.SendAsync(mail, token) Should I wait for SendComplete event for each email before sending the next?

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  • TFTP PUT Failing Across Hosts

    - by Jason
    I have a TFTP server installed on a CentOS host. /etc/xinetd.d/tftp: service tftp { disable = no socket_type = dgram protocol = udp wait = yes user = root server = /usr/sbin/in.tftpd server_args = -c -s /var/lib/tftpboot per_source = 11 cps = 100 2 flags = IPv4 } If I try to PUT a file from a remote host to the host running the TFTP server, I get Transfer Timed Out - however, it does create the file in /var/lib/tftpboot but the file is empty. If I tftp from the tftp server to itself (localhost) and PUT a file, it works fine. I have verified that SELinux is disabled and IPTables are turned off. I can connect from the remote hosts with no issue - just seems to be the PUT I have issue with: [root@SVR01 TEST]# tftp 10.100.2.15 tftp> status Connected to 10.100.2.15. Mode: netascii Verbose: off Tracing: off Literal: off Rexmt-interval: 5 seconds, Max-timeout: 25 seconds tftp>

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  • Dell Dimension 2350 with a Pentium IV processor and integrated video and network chips running Fedor

    - by Jim Dobbs
    Dell Dimension 2350 with a Pentium IV processor and integrated video and network chips running Fedora12 does a "Sleeping Beauty" and I, apparently, am not am not a "handsome prince"! The system puts video and network to sleep and it will not wakeup. I have heard of this problem on laptops, but this is a tower. Any ideas or help is appreciated. I tried to ping the network card from another system and ping fails. The logs indicate that the system continues to be active. Pressing keyboard short-cut keys makes the disk light blink but neither the video or network card comes alive. Failing all else, are there any Linux commands that I could schedule in cron to pulse video and network adapters hourly that will keep them awake? Or, should I wait on Fedora13? Before this machine, I built a Dimension 2400 with Pentium IV and it had the same problem. Fedora9 on the same hardware is fine.

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  • Is SYN flooding still a threat?

    - by Rob
    Well recently I've been reading about different Denial of Service methods. One method that kind of stuck out was SYN flooding. I'm a member of some not-so-nice forums, and someone was selling a python script that would DoS a server using SYN packets with a spoofed IP address. However, if you sent a SYN packet to a server, with a spoofed IP address, the target server would return the SYN/ACK packet to the host that was spoofed. In which case, wouldn't the spoofed host return an RST packet, thus negating the 75 second long-wait, and ultimately failing in its attempt to DoS the server?

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  • How to notify client about updated UpdatePanel content on server side

    - by csh1981
    I have a problem with UpdatePanel.Update() which works initially but then stops. I have tumbled with this problem for some time and some background is needed so please read ahead. I have an ASP.net application in which I have a subpage that display computed information in graphs. Each graph is embedded in an UpdatePanel. The graph is a user control that uses the standard asp:Chart for display. My task is to enable this page with AJAX capabilities so the page is responsive during postbacks. When I access this page from another page, during the initial page rendering, I use a wait dialog for each graph and a pageload event on the client side. In the client event, a hidden button is clicked which a server event handles (the hidden button is inside an UpdatePanel so the postback is asynchronous). Each graph is computed and the UpdatePanels are in turn updated with the Chart content. This is done using UpdatePanel.Update. And it is successful. However, I also have some RadioButtons on the page. These are dynamically created. The purpose of them is to switch graph type --- to show the same data in a different way. Same type of time consuming computation is needed in order to do so. I subscribe on each RadioButton's OnCheckedChanged event and the postback is asynchronous since the radiobuttons are inside an UpdatePanel. In the server event handler I determine the type of graph and use this as an input to the Chart control. I then remove the old Chart control from my Panel and adds new Chart and then I call UpdatePanel.Update(). But with no success. Nothing happens, no errors, nothing. Why is this?? I think this is strange because if I compute every Chart data in the initial rendering instead of using the "Wait dialog"-solution described earlier then I can select graph types successfully and all subsequent AJAX requests work as intended. Also, the same code (computing the chart, removal, and adding the Chart control to Panel and UpdatePanel.Update()) is hit during the initial rendering of the page, and it works only the first time. Here is the method that computes the graph and adds it to the panel and update the UpdatePanel: public void UpdateGraph(GraphType type, GraphMapper mapper) { //Panel is the content of UpdatePanelGraph's Panel.Controls.Clear(); chart = new Chart(type, mapper); //Computation happens inside here panel.Controls.Add(chart); //UpdatePanelGraph is in UpdateMode Conditional and has //ChildrenAsTriggers set to false UpdatePanelGraph.Update(); } I really need a way for these radiobuttons to work, possible using some clientside JavaScript or another way of handling things on the server side. I have thought about using a JavaScript postback call on the UpdatePanel instead of the UpdatePanel.Update(). However, the issue I have here is how to notify the client side when the server side is finished with computing the graph? An plausible explanation of the strange behavior is also much appreciated. Any help appreciated, thanks

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  • Browser extension (or other software) to delay page load

    - by Doug Harris
    The alt text to today's comic at xkcd.com (strip below) says: After years of trying, I broke this habit in a day by decoupling the action and the neurological reward. I set up a simple 30-second delay I had to wait through, in which I couldn't do anything else, before any new page or chat client would load (and only allowed one to run at once). The urge to check all those sites magically vanished--and my 'productive' computer use was unaffected. (bold is my emphasis) Does anybody know of a browser extension or other software that will add this sort of delay? I've seen extensions which simply block sites, but not a delay like this.

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  • windows server secondary plex or windows server default

    - by shiva
    I am new to handling issues on server. when my system tried to reboot I could see two installables to boot from. windows server 2012- current os windows server secondary plex. So when ever there is a system restart the system it stops at this screen. And since I am connecting to this server using RDP I have to wait for the hetzner console to click on of the os to boot. Even though the current os is set as default and time given is 30 sec, it still waits for a user input. So I want to know which of the two should I be using to boot and I just want one os.

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  • IBM x3620 Server takes a long time to boot past UEFI to OS

    - by Joel Coel
    I have a pair of IBM System x3620 servers. These servers do fine once they finally reach the point where the operating system takes over, but it takes them forever to get past the new-fangled UEFI boot system... a good five minutes or so; maybe longer. I haven't timed it, but it's the kind of thing where you go get a cup of coffee while you wait and it's still going when you come back. Normally the only time I shut these down is for a monthly maintenance cycle (usually just windows updates), and so it's not a big deal. But in the case where I might have an outage I'd sure like to get that 5 minutes back. Is there anything I can do to tell them to just go ahead and boot already?

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  • make sure i've configured dns correctly

    - by user22817
    Hi, On my server with Windows Server 2008, i've added a new zone with my new domain: biografica.ro. I've added a name server for it: ns.biografica.ro and the ip of the server. Also i added two A hosts for ns.biografica.ro and www.biografica.ro. I've also defined first that name server on the site where i bought the domain and pointed it to my ip. Now, i understood that i have to wait 24-48 hours for this new domain to be available online. Question: - is this a way to check on the server that i've succesfully configured it? For instance: nslookup biografica.ro or nslookup www.biografica.ro or ping www.biografica.ro do not work locally, on the server... Can you give me an advice? Thanks.

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  • Mysql Master-ColdMaster

    - by enedebe
    I explain my case: I'm at Amazon AWS and I want to be fault tolerant on a entire region failure. My basic problem is to have the db in sync with 2 regions. My options: Master-Master (high lag) Hand made sync every 5 minutes Master-ColdMaster?! (copy on the fly but Master won't wait the other region commit) In my system we could afford loosing a piece of data (we're not a bank) the last inserts in the db, but we could not afford more than 10 minutes of downtime. The database is small and the level of inserts is low, and I wouldn't affect the normal usage waiting other region commit. Is the 3 solution posible? And the most important, once the primary fail how we can detect and change the rol between master-coldmaster -- coldmaster-master ? Is there any clean-mode to restore between failure? Thank's!

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  • Windows 8 - Synaptics driver - Mouse keeps freezing

    - by KickAss
    I have Win-8 Pro installed on my Dell XPS. This has Synaptic PS/2 Port TouchPad. As I upgraded the Laptop from Win7 to Win8 all my factory Mouse software (along with other preinstalled software) was all deleted. So for the mouse, I installed Windows 8/7/XP/Vista 64/32-bit Edition v16.3.15.1. Problem - every few seconds (or minutes at times), the mouse freezes. Windows is still working, it's just the mouse. I have to wait 5-15 seconds before the mouse works again. I thought this was because the Synaptic Driver I am installing is not Win-8 compatible but this is not the case. It seems the mouse freezes when Windows is working, loading or opening new programs/windows. I have the same problem in my other Laptop which has upgraded Win8 pro. This is a Dell Studio. What's causing this?

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  • Setup a automatic server reboot on when a particular service fails

    - by user1179459
    I am running linux based server (centos 6.0) with cpanle and WHM, I have critical website running with a chat server which uses a openfire as the chat server backend server, i have monitored last few weeks this service crashes quite often, i have no way of knowing that, and i have to wait till the next day to restart the server. (and this can only be fixed by using server reboot as its got to do with some java memory problem) is there a way i can setup a monitoring service to the server and if this service goes down server itself will reboot ? is this something possible or is there a better way to overcome this problem ?

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  • window.requestFileSystem fails/events firing multiple times in PhoneGap Cordova 3

    - by ezycheez
    cordova 3.1.0-0.2.0 Droid Razr M Android 4.1.2 Windows 7 New to PhoneGap/Cordova. Running one of the filesystem demos from http://docs.phonegap.com/en/3.1.0/cordova_file_file.md.html#File. Using "cordova run android" to compile the code and run it on the phone attached via USB. Problem #1: When the app first starts I get alert("1") twice and then nothing else. Problem #2: When I kick of the code via the button onclick I get the following alert pattern: 1, 2, 2, 3, 3, 4, 6, 5, 7, 4, 6, 5, 7. Some of that makes sense based on the code flow but most of them are firing twice. I'm suspecting problem #2 is being caused by some asynchronous calls hanging out from the first attempt but no matter how long I wait those events don't fire until I kick of the code via the button. So why is the requestFileSystem call failing even though it is waiting for deviceready and why is the other code getting intermingled? Any thoughts are appreciated. <!DOCTYPE html> <html> <head> <title>FileReader Example</title> <script type="text/javascript" charset="utf-8" src="cordova.js"></script> <script type="text/javascript" charset="utf-8"> // Wait for device API libraries to load // document.addEventListener("deviceready", onDeviceReady, false); // device APIs are available // function onDeviceReady() { alert("1"); window.requestFileSystem(LocalFileSystem.PERSISTENT, 0, gotFS, fail); } function gotFS(fileSystem) { alert("2"); fileSystem.root.getFile("readme.txt", null, gotFileEntry, fail); } function gotFileEntry(fileEntry) { alert("3"); fileEntry.file(gotFile, fail); } function gotFile(file) { alert("4"); readDataUrl(file); alert("5"); readAsText(file); } function readDataUrl(file) { alert("6"); var reader = new FileReader(); reader.onloadend = function (evt) { console.log("Read as data URL"); console.log(evt.target.result); }; reader.readAsDataURL(file); } function readAsText(file) { alert("7"); var reader = new FileReader(); reader.onloadend = function (evt) { console.log("Read as text"); console.log(evt.target.result); }; reader.readAsText(file); } function fail(error) { alert("8"); console.log(error.code); } </script> </head> <body> <h1>Example</h1> <p>Read File</p> <button onclick="onDeviceReady();">Read File</button> </body> </html>

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  • Parity Initialization after putting in two new disks

    - by lbanz
    All my firmware is up to date on the server and the controllers. Storage crashed over the weekend. I rebooted it and it detected that I put in two new disks last week (I did check that both disk completed the rebuilding process last week). After it booted into the OS I see that it gave me an information message. After 18 hours it is at 54% so it is looking healthy. But I need to replace 5 more disk in the msa. Should I wait for this message to finish before replacing more disks? 785 Background parity initialization is currently queued or in progress on Logical Drive 1 (15.0 TB, RAID 5). If background parity initialization is queued, it will start when I/O is performed on the drive. When background parity initialization completes, the performance of the logical drive will improve.

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  • How to add delay in autologin

    - by raj
    I enabled autologin in my system (CentOS 6.2) for that I edited this file /etc/gdm/custom.conf In that I entered this code [daemon] AutomaticLoginEnable=true AutomaticLogin=test Here test means one account name, for that account autologin is working but the problem is not possible to logout. That is because everytime while I logout it will go to gdm(graphical display manager) and there it Again checks for account test. It is available right so it will again login to same account. Here I want add delay, that means it should wait for sometime, If no one login to any other account, then only test account will log. how to add delay?

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  • How to invert scroll wheel in certain applications using AutoHotkey?

    - by endolith
    I want to be able to modify the scrolling/middle click behavior for individual apps on Windows 7, so that the scroll to zoom direction is always consistent across apps. This script makes the middle button act as a hand tool in Adobe Acrobat, for instance: ; Hand tool with middle button in Adobe Reader #IfWinActive ahk_class AdobeAcrobat Mbutton:: #IfWinActive ahk_class AcrobatSDIWindow Mbutton:: Send {Space down}{LButton down} ; Hold down the left mouse button. KeyWait Mbutton ; Wait for the user to release the middle button. Send {LButton up}{Space up} ; Release the left mouse button. return #IfWinActive (It would be great if this could be adapted to allow "throwing" the document, too, like in Android or iPhone interfaces, but I don't know if it's possible to control scrolling that precisely) How do I invert the scroll wheel--zoom direction?

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  • GNOME/KDE Linux entirely in RAM?

    - by František Žiacik
    Hi. I'd like to have very responsive linux but I also like modern, elegant and functional desktops like gnome or kde, not the lightweight ones like xfce or lxde. Once I tried PuppyLinux and was impressed by the responsivity when I clicked an application. In my Ubuntu, it bothers me much when I click chromium and must wait 5 seconds of disk flashing until main window appears. Or evolution or anything else. Is it possible to make GNOME or KDE run entirely in RAM like PuppyLinux (of course, I mean frequently used applications and services, not all) if you have enough of it? I don't care if boot time is longer. I tried using "preload" but it didn't help much.

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  • Laptop overheating within minutes of start up

    - by Spik330
    I have a Dell Windows 7 Home Prem with an I7-720QM. More information on the computer can be found here http://www.dell.com/support/home/us/en/04/product-support/servicetag/51CVCN1/configuration The Problem I am having is the computer will over heat unnaturally fast. From the time it takes from boot to when i can run my diagnostic tools which takes about two minutes the cpu temp is 86c after a few more minutes the cpu temp will reach 100 and the computer will black screen shut down. In total the the laptop can only be run for 3-5 minutes before completely shutting off. During this time there is nothing extensive running. After the laptop shuts down you have to wait for it to cool down or it will shut off even faster sometimes 7-15 seconds well still in the boot screen. Does anyone know what could be the problem maybe a sensor or is the computer fried?

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  • How can a single disk in a hardware SATA RAID-10 array bring the entire array to a screeching halt?

    - by Stu Thompson
    Prelude: I'm a code-monkey that's increasingly taken on SysAdmin duties for my small company. My code is our product, and increasingly we provide the same app as SaaS. About 18 months ago I moved our servers from a premium hosting centric vendor to a barebones rack pusher in a tier IV data center. (Literally across the street.) This ment doing much more ourselves--things like networking, storage and monitoring. As part the big move, to replace our leased direct attached storage from the hosting company, I built a 9TB two-node NAS based on SuperMicro chassises, 3ware RAID cards, Ubuntu 10.04, two dozen SATA disks, DRBD and . It's all lovingly documented in three blog posts: Building up & testing a new 9TB SATA RAID10 NFSv4 NAS: Part I, Part II and Part III. We also setup a Cacit monitoring system. Recently we've been adding more and more data points, like SMART values. I could not have done all this without the awesome boffins at ServerFault. It's been a fun and educational experience. My boss is happy (we saved bucket loads of $$$), our customers are happy (storage costs are down), I'm happy (fun, fun, fun). Until yesterday. Outage & Recovery: Some time after lunch we started getting reports of sluggish performance from our application, an on-demand streaming media CMS. About the same time our Cacti monitoring system sent a blizzard of emails. One of the more telling alerts was a graph of iostat await. Performance became so degraded that Pingdom began sending "server down" notifications. The overall load was moderate, there was not traffic spike. After logging onto the application servers, NFS clients of the NAS, I confirmed that just about everything was experiencing highly intermittent and insanely long IO wait times. And once I hopped onto the primary NAS node itself, the same delays were evident when trying to navigate the problem array's file system. Time to fail over, that went well. Within 20 minuts everything was confirmed to be back up and running perfectly. Post-Mortem: After any and all system failures I perform a post-mortem to determine the cause of the failure. First thing I did was ssh back into the box and start reviewing logs. It was offline, completely. Time for a trip to the data center. Hardware reset, backup an and running. In /var/syslog I found this scary looking entry: Nov 15 06:49:44 umbilo smartd[2827]: Device: /dev/twa0 [3ware_disk_00], 6 Currently unreadable (pending) sectors Nov 15 06:49:44 umbilo smartd[2827]: Device: /dev/twa0 [3ware_disk_07], SMART Prefailure Attribute: 1 Raw_Read_Error_Rate changed from 171 to 170 Nov 15 06:49:45 umbilo smartd[2827]: Device: /dev/twa0 [3ware_disk_10], 16 Currently unreadable (pending) sectors Nov 15 06:49:45 umbilo smartd[2827]: Device: /dev/twa0 [3ware_disk_10], 4 Offline uncorrectable sectors Nov 15 06:49:45 umbilo smartd[2827]: Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error Nov 15 06:49:45 umbilo smartd[2827]: # 1 Short offline Completed: read failure 90% 6576 3421766910 Nov 15 06:49:45 umbilo smartd[2827]: # 2 Short offline Completed: read failure 90% 6087 3421766910 Nov 15 06:49:45 umbilo smartd[2827]: # 3 Short offline Completed: read failure 10% 5901 656821791 Nov 15 06:49:45 umbilo smartd[2827]: # 4 Short offline Completed: read failure 90% 5818 651637856 Nov 15 06:49:45 umbilo smartd[2827]: So I went to check the Cacti graphs for the disks in the array. Here we see that, yes, disk 7 is slipping away just like syslog says it is. But we also see that disk 8's SMART Read Erros are fluctuating. There are no messages about disk 8 in syslog. More interesting is that the fluctuating values for disk 8 directly correlate to the high IO wait times! My interpretation is that: Disk 8 is experiencing an odd hardware fault that results in intermittent long operation times. Somehow this fault condition on the disk is locking up the entire array Maybe there is a more accurate or correct description, but the net result has been that the one disk is impacting the performance of the whole array. The Question(s) How can a single disk in a hardware SATA RAID-10 array bring the entire array to a screeching halt? Am I being naïve to think that the RAID card should have dealt with this? How can I prevent a single misbehaving disk from impacting the entire array? Am I missing something?

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