Re: Disable aggregation of requests

2009-02-22 Thread Or Gerlitz
Mark van Walraven wrote: > I'm afraid nothing springs to mind ... google and read and read and read > and then experiment with your own workloads. thanks, I was just checking with you any recomendation on what to read... Or. --~--~-~--~~~---~--~~ You received thi

Re: Disable aggregation of requests

2009-02-22 Thread Mark van Walraven
On Fri, Feb 20, 2009 at 09:25:37AM +0200, Or Gerlitz wrote: > Thanks a lot for sharing your experience and thoughts, any good > article/paper (e.g OLS) you can recommend on this matter? I'm afraid nothing springs to mind ... google and read and read and read and then experiment with your own work

Re: Disable aggregation of requests

2009-02-19 Thread Or Gerlitz
On Thu, Feb 19, 2009 at 9:53 PM, Mark van Walraven > > In my experience, noop works well on the initiator. On the target, > deadline is slightly better than noop on the target for the workloads > I see, on my equipment, YMMV. Thanks a lot for sharing your experience and thoughts, any good arti

Re: Disable aggregation of requests

2009-02-19 Thread Mark van Walraven
On Thu, Feb 19, 2009 at 09:28:31PM +0200, Or Gerlitz wrote: > Sorry, but why file system over block device whose scheduler being > noop is a bad idea? The noop scheduler doesn't re-order requests, so concurrent accesses to multiple files will cause lots of extra seeking and throughput collapses.

Re: Disable aggregation of requests

2009-02-19 Thread Or Gerlitz
>> Does anyone know why noop is not the default I/O scheduler? > It is a very bad idea in case of using a filesystem which is usually the > point. Sorry, but why file system over block device whose scheduler being noop is a bad idea? Or. --~--~-~--~~~---~--~~ Y

Re: Disable aggregation of requests

2009-02-19 Thread Konrad Rzeszutek
On Thu, Feb 19, 2009 at 09:13:10PM +0200, Boaz Harrosh wrote: > > Or Gerlitz wrote: > > Boaz Harrosh wrote: > >> You can select the no-op I/O elevator and you can also use direct IO > >> like with sg_dd from the sg_utils package > >> > > Does anyone know why noop is not the default I/O schedul

Re: Disable aggregation of requests

2009-02-19 Thread Boaz Harrosh
Or Gerlitz wrote: > Boaz Harrosh wrote: >> You can select the no-op I/O elevator and you can also use direct IO >> like with sg_dd from the sg_utils package >> > Does anyone know why noop is not the default I/O scheduler? > It is a very bad idea in case of using a filesystem which is usually

Re: Disable aggregation of requests

2009-02-19 Thread Boaz Harrosh
Erez Zilber wrote: >>> >> You can select the no-op I/O elevator and you can also use direct IO >> like with sg_dd from the sg_utils package >> > > I'm using noop already, but that didn't help. I'll try to ask in lkml. > > Thanks, > Erez > Using the sg3-utils package sg_dd command you can issue

Re: Disable aggregation of requests

2009-02-19 Thread Or Gerlitz
Boaz Harrosh wrote: > You can select the no-op I/O elevator and you can also use direct IO > like with sg_dd from the sg_utils package > Does anyone know why noop is not the default I/O scheduler? Or. --~--~-~--~~~---~--~~ You received this message because you

Re: Disable aggregation of requests

2009-02-19 Thread Erez Zilber
On Wed, Feb 18, 2009 at 10:09 PM, Boaz Harrosh wrote: > > Mike Christie wrote: >> Erez Zilber wrote: >>> On Tue, Feb 17, 2009 at 11:35 PM, Mike Christie >>> wrote: Erez Zilber wrote: > Hi, > > I'm running a setup of open-iscsi connected to a target. When I run > I/O from th

Re: Disable aggregation of requests

2009-02-18 Thread Boaz Harrosh
Mike Christie wrote: > Erez Zilber wrote: >> On Tue, Feb 17, 2009 at 11:35 PM, Mike Christie wrote: >>> Erez Zilber wrote: Hi, I'm running a setup of open-iscsi connected to a target. When I run I/O from the initiator (e.g using dd) with transaction size of 128kB, I somet

Re: Disable aggregation of requests

2009-02-18 Thread Mike Christie
Erez Zilber wrote: > On Tue, Feb 17, 2009 at 11:35 PM, Mike Christie wrote: >> Erez Zilber wrote: >>> Hi, >>> >>> I'm running a setup of open-iscsi connected to a target. When I run >>> I/O from the initiator (e.g using dd) with transaction size of 128kB, >>> I sometimes see that 2 128kB requests

Re: Disable aggregation of requests

2009-02-18 Thread Erez Zilber
On Wed, Feb 18, 2009 at 10:36 AM, Ulrich Windl wrote: > > On 18 Feb 2009 at 8:44, Erez Zilber wrote: > >> >> On Tue, Feb 17, 2009 at 11:35 PM, Mike Christie wrote: >> > >> > Erez Zilber wrote: >> >> Hi, >> >> >> >> I'm running a setup of open-iscsi connected to a target. When I run >> >> I/O fro

Re: Disable aggregation of requests

2009-02-18 Thread Ulrich Windl
On 18 Feb 2009 at 8:44, Erez Zilber wrote: > > On Tue, Feb 17, 2009 at 11:35 PM, Mike Christie wrote: > > > > Erez Zilber wrote: > >> Hi, > >> > >> I'm running a setup of open-iscsi connected to a target. When I run > >> I/O from the initiator (e.g using dd) with transaction size of 128kB, > >>

Re: Disable aggregation of requests

2009-02-17 Thread Erez Zilber
On Tue, Feb 17, 2009 at 11:35 PM, Mike Christie wrote: > > Erez Zilber wrote: >> Hi, >> >> I'm running a setup of open-iscsi connected to a target. When I run >> I/O from the initiator (e.g using dd) with transaction size of 128kB, >> I sometimes see that 2 128kB requests are aggregated to a sing

Re: Disable aggregation of requests

2009-02-17 Thread Mike Christie
Erez Zilber wrote: > Hi, > > I'm running a setup of open-iscsi connected to a target. When I run > I/O from the initiator (e.g using dd) with transaction size of 128kB, > I sometimes see that 2 128kB requests are aggregated to a single 256kB > request. This is rare, but it happens from time to ti

Disable aggregation of requests

2009-02-17 Thread Erez Zilber
Hi, I'm running a setup of open-iscsi connected to a target. When I run I/O from the initiator (e.g using dd) with transaction size of 128kB, I sometimes see that 2 128kB requests are aggregated to a single 256kB request. This is rare, but it happens from time to time. Can I disable this feature?