0
votes
1answer
540 views

Input/output error reading USB backup drive on CentOS 6.4

I'm suddenly seeing some strange behaviour on our USB backup drive that doesn't make sense to me: (2013-10-21 14:58:23 [root@newdc /]$ cd /mnt/backup/ (2013-10-21 14:59:03 [root@newdc backup]$ ls -la ...
2
votes
4answers
3k views

Flush-0:n processes causing massive bottleneck

I have a LAMP cluster that shares files via NFS and occasionally one of them will be stricken for a while when mysterious flush processes start appearing. Can anyone help me? The only way to resolve ...
2
votes
2answers
4k views

jbd2/dm-0-8 consuming all I/O

What is jbd2/dm-0-8 and why It is consuming all my I/O usage and causing I/O wait? Is there anyway to disable this? Bonnie++ results: http://pastebin.com/iQCWP1qp $ sudo hdparm -t /dev/sda1 ...
-1
votes
3answers
2k views

iostat shows 100% utilization - what can be done to improve performance?

I have dedicated web server with CentOS. Recently, I get very high server load, probably caused due to IO bottleneck. iostat -mx 3 shows: avg-cpu: %user %nice %system %iowait %steal %idle ...
1
vote
0answers
424 views

I/O error on non-existent device?

Getting the following in /var/log/messages: Sep 17 10:38:53 server1 kernel: end_request: I/O error, dev sde, sector 0 Sep 17 10:38:53 server1 kernel: end_request: I/O error, dev sde, sector 63 Sep 17 ...
1
vote
3answers
370 views

Extremely High Hard Disk Reading Usage

My VPS configuration is as follows: H.D.D = 25GB RAM = 256MB OS : CentOS 5.5 I received an email from server provider showing that my VPS H.D.D read usage is 137GB in one day. I have installed ...
0
votes
1answer
681 views

I/O Xen Server on disk filesystem ext4

I have a Xen Server 6.0 and one disk (2TB) report I/O error my vm is Centos 6.2 (filesystem ext4) end_request: I/O error, dev xvdc, sector 896084224 end_request: I/O error, dev xvdc, sector 896084312 ...
2
votes
2answers
302 views

Detecting Disk Writes Linux

my webserver running centos 5.7 is showing quite a lot of disk write activity which I cannot explain really. I run a few websites on this server with the help of nginx and php-fpm and xcache. On the ...
0
votes
4answers
573 views

How can I get a list of Programs doing Disk IO?

I have a server (running CentOS 5) and I need to figure out which programs (MySQL, Apache, etc) are doing the most Disk I/O? Is there a command that will allow me to calculate an average over time?
6
votes
4answers
226 views

Frequently accessed files and I/O usage

I'm curious, from a performance standpoint, is there an advantage in storing all files in one directory versus having each file in a separate directory? I'm not concerned about organization. Also, ...