Search Results

Search found 16947 results on 678 pages for 'kernel programming'.

Page 451/678 | < Previous Page | 447 448 449 450 451 452 453 454 455 456 457 458  | Next Page >

  • How do you manage updates without a staging environment: CentOS 6.3

    - by Gregg Leventhal
    I am managing about 20 servers, many of them virtual. They are almost all different purpose, and none are clustered. I have a distributed LAMP stack, a few application servers, some build servers, a few KVM hosts. They are CentOS 6.3 mostly with a few Ubuntu (unfortunately). I don't have the resources to setup a staging environment where I can have duplicates of my machines and test updates before rolling them out. I am taking file backups. What I want to know is how you are approaching backing up your Linux systems. I assume you don't just do yum update, but then how are you choosing the packages worthy of updating? When (if ever) are you updating the kernel, etc.. How do you test updates without a staging environment? Snapshot and hope for the best?

    Read the article

  • iPhone memory management

    - by Prazi
    I am newbie to iPhone programming. I am not using Interface Builder in my programming. I have some doubt about memory management, @property topics in iPhone. Consider the following code @interface LoadFlag : UIViewController { UIImage *flag; UIImageView *preview; } @property (nonatomic, retain) UIImageView *preview; @property (nonatomic, retain) UIImage *flag; @implementation @synthesize preview; @synthesize flag; - (void)viewDidLoad { flag = [UIImage imageNamed:@"myImage.png"]]; NSLog(@"Preview: %d\n",[preview retainCount]); //Count: 0 but shouldn't it be 1 as I am retaining it in @property in interface file preview=[[UIImageView alloc]init]; NSLog(@"Count: %d\n",[preview retainCount]); //Count: 1 preview.frame=CGRectMake(0.0f, 0.0f, 100.0f, 100.0f); preview.image = flag; [self.view addSubview:preview]; NSLog(@"Count: %d\n",[preview retainCount]); //Count: 2 [preview release]; NSLog(@"Count: %d\n",[preview retainCount]); //Count: 1 } When & Why(what is the need) do I have to set @property with retain (in above case for UIImage & UIImageView) ? I saw this statement in many sample programs but didn't understood the need of it. When I declare @property (nonatomic, retain) UIImageView *preview; statement the retain Count is 0. Why doesn't it increase by 1 inspite of retaining it in @property. Also when I declare [self.view addSubview:preview]; then retain Count increments by 1 again. In this case does the "Autorelease pool" releases for us later or we have to take care of releasing it. I am not sure but I think that the Autorelease should handle it as we didn't explicitly retained it so why should we worry of releasing it. Now, after the [preview release]; statement my count is 1. Now I don't need UIImageView anymore in my program so when and where should I release it so that the count becomes 0 and the memory gets deallocated. Again, I am not sure but I think that the Autorelease should handle it as we didn't explicitly retained it so why should we worry of releasing it. What will happen if I release it in -(void) dealloc method In the statement - flag = [UIImage imageNamed:@"myImage.png"]]; I haven't allocated any memory to flag but how can I still use it in my program. In this case if I do not allocate memory then who allocates & deallocates memory to it or is the "flag" just a reference pointing to - [UIImage imageNamed:@"myImage.png"]];. If it is a reference only then do i need to release it. Thanks in advance.

    Read the article

  • Windows 7 freezing unexpectedly

    - by Thomas Deutsch
    I have a Windows 7 computer here, which is freezing between 2 times a day and 1 time every second day. I see no problem, no special drivers, no special Apps are open, no encryption or something like that. Apps usually open then are Firefox, Thunderbird, Eclipse and maybe Office. Computer is just freezing. No Reboot, no shutdown, no bluescreen and no error. User has to hardreset it. Eventlog shows me an kernel error saying it has been unexpected rebooted due to an fatal error, but no statement about what kind of error happended. Anyone an idea what it can be? Chkdisk should be ok (currently, I run it a second time).

    Read the article

  • Is giving read permissions on /etc/shadow to apache user a wise decision from security point of view?

    - by Czar
    I have to use PAM authentication for DAV SVN, but when everything is configured as specified in mod_auth_pam documentation, authentication does not work. After some research I realized, that for this to work, httpd should be running under root user (which I don't like and won't implement) or apache user (under which httpd is running by default) should have permissions to read /etc/shadow file. So there is a pair of questions connected to each other which I want to ask: Is giving this permition to apache user a wise decision from security point of view? If answer to the first question is "yes", what is the correct way to do so? For now I've done following: groupadd shadow usermod -G shadow apache chmod g+r /etc/shadow Another way I can come up with is using acl: setfacl -m u:apache:r /etc/shadow Note: OS is Fedora 14 x86_64 (kernel: 2.6.35.11) httpd v2.2.17 mod_auth_pam v1.1.1

    Read the article

  • Impossible to stop raid device

    - by Traroth
    I'm trying to stop a RAID disk in order to replace it by a new one, as this one is not working properly. I'm typing mdadm --stop /dev/md1, and I'm getting an error message: mdadm: fail to stop array /dev/md1: Device or resource busy I'm getting this message even if I reboot the server, and I can't see a process that could cause this. The server is working under a Debian with a 2.6.18-4-amd64 kernel. Could you help? Edit: Mote details about what my colleague tried out. After unmounting sda1, the command mdadm --remove /dev/md0 /dev/sda1 worked. But now, we still have an error message after mdadm --remove /dev/md1 /dev/sda5: mdadm: hot remove failed for /dev/sda5: Device or resource busy I still don't understand completly how the different partitions are mounted, so I suppose there is something I don't understand in the currenct situation...

    Read the article

  • Task managment for team

    - by Kartoch
    I'm looking for a web application to manage tasks (not necessary programming-oriented) for a small team. It must be easy to setup and maintain. It must offer file upload and mail users in case of a change. There is hundred of solutions available but most are too complex for what we want or are not "stable" (not updated since a long time, not very well programmed). i was wondering if stack overflow's folks have some recommendations...

    Read the article

  • Horrible VMware keyboard shortcuts

    - by rshimoda
    Hello, I'm a VMware user and far too often I use keyboard shortcuts while programming. However, this has proved to be quite distressing as sometimes the VMware gets hold of it and turns off / pauses (ctrl+Z) the virtual machine. Is there a way to disable keyboard shortcuts on VMware? Has anyone here ever found a workaround?

    Read the article

  • rsync doesn't use delta transfer on first run

    - by ockzon
    I'm trying to synchronize a large local directory (with a batch file using rsync 3.0.7 on Cygwin, Windows 7 x64, 30k files, 200gb size) to a remote server (Debian x64 with kernel 2.6, rsyncd 3.0.7) over a slow internet connection (90kbyte/s upload). I know almost all files are identical and I verified that using md5sum locally and remotely. However when executing rsync from my local machine every file gets transferred completely for the first time. When I terminate the batch file after a few transfers and run it again then the already transferred files are skipped. But as soon as it gets to a file not yet transferred it uploads the file as a whole again instead of noticing that the checksum is the same locally and remotely. The batch file calling rsync looks like this (backslashes and line brakes added here for readability): c:\cygwin\bin\rsync.exe --verbose --human-readable --progress --stats \ --recursive --ignore-times --password-file pwd.txt \ /cygdrive/d/ftp/data/ \ rsync://[email protected]:33400/data/ | \ c:\cygwin\bin\tee.exe --append rsync.log I experimented using the following parameters in varying combinations but that didn't help either: --checksum --partial --partial-dir=/tmp/.rsync-partial --compress

    Read the article

  • Serial port data availability problem

    - by harry
    Hello Evryone. I am new to this type of programming..i just want some help...regarding what to do when u need to extract the data from the serial port..and how to check that tha data is available in the serial port..so that no data loss is there....

    Read the article

  • What is the relationship between domNode and htmlelement?

    - by Turtle
    Hello, I am confused about the two terms. What is the difference in browser-side javascript programming? I use dojo as framework. And there is only the concept of domNode. But browser debugger always told me something as htmlelement. Are they just the same thing with different names, or with some subtle differences? Thanks.

    Read the article

  • Where can I find a good software implementation plan template?

    - by Corpsekicker
    This is not "programming" related as much as it is "software engineering" related. I am required to produce an implementation for additional functionality to a complete system. All I am armed with is knowledge of the existing architecture and a functional spec with visual requirements, user stories and use cases. Is there a standardised way to go about this? I suck at documentation.

    Read the article

  • ip routes to specific interface

    - by user65053
    I am trying to figure out how to get all traffic to 10.8.78.* to connect using interface ppp0 when available how would I properly handle this (centos) and can I fall back on eth0 when pp0 is not up? /sbin/route -n Kernel IP routing table Destination Gateway Genmask Flags Metric Ref Use Iface 69.19.219.69 0.0.0.0 255.255.255.255 UH 0 0 0 ppp0 10.0.1.0 0.0.0.0 255.255.255.0 U 0 0 0 eth0 169.254.0.0 0.0.0.0 255.255.0.0 U 0 0 0 eth0 0.0.0.0 10.0.1.1 0.0.0.0 UG 0 0 0 eth0

    Read the article

  • Can somebody link me to some code where there is a fantastic or a nice use of Inheritance

    - by Soham
    I strongly believe that, reading code and reading good code is key to great programming. If not one of the many. I had been facing some problems in visualizing and having a "feel" of using inheritance to better my code architecture. Can somebody give me some link to good code to emulate, where folks have used inheritance in an absolute "kung-fooey ruthless" manner [in a good way]

    Read the article

  • How to tell if linux disk IO is causing excessive (> 1 second) application stalls

    - by noahz
    I have a Java application performing a large volume (hundreds of MB) of continuous output (streaming plain text) to about a dozen files a ext3 SAN filesystem. Occasionally, this application pauses for several seconds at a time. I suspect that something related to ext3 vsfs (Veritas Filesystem) functionality (and/or how it interacts with the OS) is the culprit. What steps can I take to confirm or refute this theory? I am aware of iostat and /proc/diskstats as starting points. Revised title to de-emphasize journaling and emphasize "stalls" I have done some googling and found at least one article that seems to describe behavior like I am observing: Solving the ext3 latency problem Additional Information Red Hat Enterprise Linux Server release 5.3 (Tikanga) Kernel: 2.6.18-194.32.1.el5 Primary application disk is fiber-channel SAN: lspci | grep -i fibre 14:00.0 Fibre Channel: Emulex Corporation Saturn-X: LightPulse Fibre Channel Host Adapter (rev 03) Mount info: type vxfs (rw,tmplog,largefiles,mincache=tmpcache,ioerror=mwdisable) 0 0 cat /sys/block/VxVM123456/queue/scheduler noop anticipatory [deadline] cfq

    Read the article

  • Upgrading PHP 5.1 to 5.3 on Linux Server

    - by nicorellius
    I trying to find the best way to upgrade from PHP 5.1 to 5.3. The CRM software I am running on this server requires this upgrade or else I probably wouldn't even perform it, because it seems like it's going to be perhaps trickier than I hoped it would be. Being still new to the programming world, these routine upgrades are still worrisome to me. I am running apache 2.2.6 (Fedora), PHP 5.1.6 and MySQL 5.0.27 on this server.

    Read the article

  • Is Odersky serious with "bills !*&^%~ code!" ?

    - by stacker
    In his book programming in scala (Chapter 5 Section 5.9 Pg 93) Odersky mentioned this expression "bills !*&^%~ code! In the footnote on same page: "By now you should be able to figure out that given this code,the Scala compiler would invoke (bills.!*&^%~(code)).!()." That's a bit to cryptic for me, could someone explain what's going on here?

    Read the article

  • Objects With No Behavior

    - by Patrick Donovan
    I've been teaching myself object oriented programming and I'm thinking about a situation where I have an object "Transaction", that has quite a few properties to it like account, amount, date, currency, type, etc. I never plan to mutate these data points, and calculation logic will live in other classes. My question is, is it poor Python design to instantiate thousands of objects just to hold data? I find the data far easier to work with embedded in a class rather than trying to cram it into some combination of data structures.

    Read the article

  • How would you explain your job to a 5-year old?

    - by Canavar
    Sometimes it's difficult to define programming to people. Especially too old or too young people can not understand what I do to earn money. They think that I repair computers, or they want to think that I (as an engineer) build computers at work. :) It's really hard to tell people that you produce something they can't touch. Here is a funny question, how would you explain your job to a 5-year-old?

    Read the article

  • Best Python IDE for my situation

    - by ChrisC
    I want to write a database app in Python, using SQLite and wxPython. My only "experience" is 1 class on basic C++ console programming and OOP concepts. Which IDE would be best for my situation? In case it matters, I only need my new program to run on Windows, and I do want to make it "portable". Thank you.

    Read the article

< Previous Page | 447 448 449 450 451 452 453 454 455 456 457 458  | Next Page >