Re: How can I boost block I/O performance

[Dave Pitts]

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@xxxxxxxx              My other RV IS a Pullman (Colorado Pine).
http://www.cozx.com/~dpitts

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