Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
As Maciej says, you might be hitting the limit of the disk. In your circumstance where the disk accesses are slow and the load average is going up I'd take a direct look at the IO wait. You could be spending much of your cpu cycles waiting on the disk(s). IO wait is found in the CPU section as the 'wa' field when you run vmstat or top.
This systemtap is useful in letting you know exactly which processes are utilizing the disk(s) the most if you're trying to figure out which process is causing the problem.
http://sourceware.org/systemtap/wiki/ScriptsTools?action=AttachFile&do=view&target=disktop.txt
I had to install the kernel debugging packages and systemtap to get it to work. It gives output like this...
Fri Oct 10 13:29:47 2008 , Average: 353Kb/sec, Read: 1764Kb, Write: 2Kb
UID PID PPID CMD DEVICE T BYTES
500 3425 3424 bash dm-1 R 1492302
0 3422 2037 sshd dm-1 R 260286
500 3428 3427 id dm-1 R 6944
500 3447 3446 id dm-1 R 6944
500 3445 3444 id dm-1 R 5717
500 3426 3425 xauth dm-1 R 3910
0 3424 3422 sshd dm-1 R 3846
500 3433 3425 egrep dm-1 R 3636
500 3432 3431 dircolors dm-1 R 3124
500 3430 3429 hostname dm-1 R 2751
Brandon Poyner
Network Engineer III
CCAC - College Office
412-237-3086
> -----Original Message-----
> From: drbd-user-bounces at lists.linbit.com [mailto:drbd-user-
> bounces at lists.linbit.com] On Behalf Of Maciej Bogucki
> Sent: Friday, October 10, 2008 2:06 AM
> To: Lorenzo Milesi
> Cc: drbd-user at lists.linbit.com
> Subject: Re: [DRBD-user] high load average
>
> Lorenzo Milesi wrote:
> > hi
> >
> > after 6 months of usage I'm running in this problem: high load
> average!
> > When accessing the drbd device the load flies to >1, even to 2 or 5,
> > disk access is very slow, and when drbd sync is in progress it's
> almost
> > impossible to use.
> > I've been using this configuration for many months so far, without
> big
> > problems (at least like this). Now i'm running into this issue... how
> > can i debug it?
> >
> > thanks!
> >
> Hello,
>
> Check disk utilisation. Use /iostat/ command which provides information
> about /IOPS/ and the amount of data processed during each IO. /Maybe/
> You’ve /reached Your disks barrier and You would need to add more one.
>
> Best Regards
> Maciej Bogucki
> /
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