Re: How can I boost block I/O performance

[Dave Pitts <dpitts@cozx.com>]

Avi Kivity wrote:

> Dave Pitts wrote:
>
>> Hello all:
>>
>> I've been trying some hacks to boost disk I/O performance mostly by 
>> changing values
>> in the /proc/sys/vm filesystem.  A vmstat display shows bursty block 
>> out counts with
>> fairly consistent interrupt counts:
>>
>> procs -----------memory---------- ---swap-- -----io---- --system-- 
>> ----cpu----
>> r  b   swpd   free   buff  cache   si   so    bi    bo   in    cs us 
>> sy id wa
>> 4  0    720  80252   1820 7077456    0    0     9   852    5    11  1 
>> 14 84  0
>
> [...]
>
>> 5  0    720  90364   1860 7067080    0    0    40 66956 17995 95384  
>> 0 17 82  0
>>
>> This test is running several NFS clients to a RAID disk storage 
>> array. I also see the
>> same behavior when running SFTP transfers. What I'd like is a more 
>> even block
>> out behavior (even at the expense of other apps as this is a file 
>> server not an app
>> server).  The values that I've been hacking are the 
>> dirty_writeback_centisecs,
>> dirty_background_ratio, etc. Am I barking up the wrong tree?
>
> No  iowait time, plenty of idle time: looks like you are network 
> bound. What time of network are you running?
>
Well, it's an 8 cpu system. Does the idle time reflect the idle time of 
all cpu's?
The network is a Gigabit Ethernet.


-- 
Dave Pitts                   PULLMAN: Travel and sleep in safety and comfort.
dpitts@cozx.com              My other RV IS a Pullman (Colorado Pine).
http://www.cozx.com/~dpitts