Re: [Bacula-users] minimize iowait

2008-12-11 Thread John Drescher
On Thu, Dec 11, 2008 at 3:01 PM, John Drescher wrote: >> In the example you given here >> http://forums.gentoo.org/viewtopic-t-709075-highlight-.html >> >> md1 has a chunk size of 256K vs md2 has 64K is that something I can >> set? is there a preferred chunk size ? Can that be changed or is that >

Re: [Bacula-users] minimize iowait

2008-12-11 Thread John Drescher
> In the example you given here > http://forums.gentoo.org/viewtopic-t-709075-highlight-.html > > md1 has a chunk size of 256K vs md2 has 64K is that something I can > set? is there a preferred chunk size ? Can that be changed or is that > system hardware set only? > You set this when you create t

Re: [Bacula-users] minimize iowait

2008-12-11 Thread Lukasz Szybalski
On Thu, Dec 11, 2008 at 12:55 PM, John Drescher wrote: >> 1. SO I have done the strip size to 2048 which gave me a performance >> boost from 30mb/s to 104mb/s on a bs=1M >> > I find that bigger stripe sizes (than the default 64k) give you worse > write performance and higher iowait but better read

Re: [Bacula-users] minimize iowait

2008-12-11 Thread John Drescher
> 1. SO I have done the strip size to 2048 which gave me a performance > boost from 30mb/s to 104mb/s on a bs=1M > I find that bigger stripe sizes (than the default 64k) give you worse write performance and higher iowait but better read performance on large files. > > 2. What would be a difference

Re: [Bacula-users] minimize iowait

2008-12-11 Thread Lukasz Szybalski
On Thu, Dec 11, 2008 at 9:47 AM, John Drescher <[EMAIL PROTECTED]> wrote: >> Software raid5 using mdadm >> > If this happens during writes. Take a look at the following forum post of > mine. > > http://forums.gentoo.org/viewtopic-p-5307393.html#5307393 > > Also follow the link to the place where I

Re: [Bacula-users] minimize iowait

2008-12-11 Thread John Drescher
> Software raid5 using mdadm > If this happens during writes. Take a look at the following forum post of mine. http://forums.gentoo.org/viewtopic-p-5307393.html#5307393 Also follow the link to the place where I show benchmarks: http://forums.gentoo.org/viewtopic-t-709075-highlight-.html Also if

Re: [Bacula-users] minimize iowait

2008-12-11 Thread Lukasz Szybalski
On Thu, Dec 11, 2008 at 3:51 AM, Pasi Kärkkäinen <[EMAIL PROTECTED]> wrote: > On Wed, Dec 10, 2008 at 04:38:58PM -0600, Lukasz Szybalski wrote: >> On Wed, Dec 10, 2008 at 4:06 PM, John Drescher <[EMAIL PROTECTED]> wrote: >> > On Wed, Dec 10, 2008 at 4:10 PM, Lukasz Szybalski <[EMAIL PROTECTED]> >>

Re: [Bacula-users] minimize iowait

2008-12-11 Thread Pasi Kärkkäinen
On Wed, Dec 10, 2008 at 04:38:58PM -0600, Lukasz Szybalski wrote: > On Wed, Dec 10, 2008 at 4:06 PM, John Drescher <[EMAIL PROTECTED]> wrote: > > On Wed, Dec 10, 2008 at 4:10 PM, Lukasz Szybalski <[EMAIL PROTECTED]> wrote: > >> Hello, > >> My bacula server is pretty busy, and I notice that at times

Re: [Bacula-users] minimize iowait

2008-12-10 Thread Lukasz Szybalski
On Wed, Dec 10, 2008 at 4:06 PM, John Drescher <[EMAIL PROTECTED]> wrote: > On Wed, Dec 10, 2008 at 4:10 PM, Lukasz Szybalski <[EMAIL PROTECTED]> wrote: >> Hello, >> My bacula server is pretty busy, and I notice that at times the IOwait >> reaches 40%. >> >> Currently I use: top, free, iostat -k 5

Re: [Bacula-users] minimize iowait

2008-12-10 Thread John Drescher
On Wed, Dec 10, 2008 at 4:10 PM, Lukasz Szybalski <[EMAIL PROTECTED]> wrote: > Hello, > My bacula server is pretty busy, and I notice that at times the IOwait > reaches 40%. > > Currently I use: top, free, iostat -k 5 /dev/md5 > > Are there any tools/commands on linux that can tell me what is the >