[CentOS] Re: DRBD NFS load issues

Mon Jan 7 07:12:40 UTC 2008
Jed Reynolds <lists at bitratchet.com>

Jed Reynolds wrote:
> Ugo Bellavance wrote:
>
>>
>> Can you send us the output of vmstat -n 5 5
>> when you're doing a backup?
>>
>
> This is with rsync at bwlimit=2500
>

This is doing the same transfer with SSH. The load still climbs...and 
then load drops. I think NFS is the issue.

I wonder if my NFS connection settings in client fstabs are unwise? I 
figured with beefy machine and fast networking, I could take advantage 
of large packetsizes. Bad packet sizes?

rw,hard,intr,rsize=16384,wsize=16384


top - 23:04:35 up 3 days, 10:34,  4 users,  load average: 4.08, 3.06, 2.81
Tasks: 132 total,   1 running, 131 sleeping,   0 stopped,   0 zombie
Cpu0  :  5.7% us,  1.7% sy,  0.0% ni, 72.0% id, 19.3% wa,  0.7% hi,  0.7% si
Cpu1  :  1.3% us,  3.0% sy,  0.0% ni, 38.4% id, 51.0% wa,  0.7% hi,  5.6% si
Mem:   8169712k total,  8149288k used,    20424k free,   162628k buffers
Swap:  4194296k total,      160k used,  4194136k free,  6374960k cached

then

top - 23:08:49 up 3 days, 10:39,  4 users,  load average: 0.89, 1.86, 2.38
Tasks: 129 total,   1 running, 128 sleeping,   0 stopped,   0 zombie
Cpu0  :  5.2% us,  2.8% sy,  0.0% ni, 63.7% id, 23.4% wa,  1.2% hi,  3.8% si
Cpu1  :  1.2% us,  3.2% sy,  0.0% ni, 65.9% id, 27.3% wa,  1.0% hi,  1.4% si
Mem:   8169712k total,  8149512k used,    20200k free,   141388k buffers
Swap:  4194296k total,      160k used,  4194136k free,  6388856k cached


 $ vmstat -n 5 5
procs -----------memory---------- ---swap-- -----io---- --system-- 
----cpu----
 r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us sy 
id wa
 0  0    160  18712 155060 6383956    0    0    96    45   42    70  0  
2 89  9
 0  0    160  20128 154328 6382988    0    0   421  2578 7622  2433  3  
4 64 29
 0  0    160  18192 153920 6384076    0    0   126  2498 7116  2238  3  
6 72 19
 0  1    160  22872 153684 6380640    0    0   110  2451 7065  2063  3  
4 64 28
 0  0    160  23880 153416 6379752    0    0    34  2520 7091  2506  3  
4 68 25