elevators and sw raid
Is there a particular elevator that generally works best with software raid-1? (More generally, what is the relationship, if any, between elevators and sw raid?) -- -Eric 'shubes' --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
Re: elevators and sw raid
Maybe http://www.otisworldwide.com/ ? (Sorry, couldn't resist.) Side track: What does the word "elevator" mean in the context of RAID? Alan On Tue, Sep 28, 2010 at 8:59 AM, Eric Shubert wrote: > Is there a particular elevator that generally works best with software > raid-1? > > (More generally, what is the relationship, if any, between elevators and sw > raid?) > > -- > -Eric 'shubes' > > --- > PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us > To subscribe, unsubscribe, or to change your mail settings: > http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss > --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
Re: elevators and sw raid
Alan Dayley wrote: Maybe http://www.otisworldwide.com/ ? (Sorry, couldn't resist.) Side track: What does the word "elevator" mean in the context of RAID? Alan On Tue, Sep 28, 2010 at 8:59 AM, Eric Shubert <mailto:e...@shubes.net>> wrote: Is there a particular elevator that generally works best with software raid-1? (More generally, what is the relationship, if any, between elevators and sw raid?) -- -Eric 'shubes' --- Ha! In the linux kernel, the I/O scheduler is referred to as the elevator. It can be set to one of 4 values in the 2.6 kernel using the elevator= kernel parameter at boot time. Each block device's scheduler is determined by the value in /sys/block//queue/scheduler $ cat /sys/block/sda/queue/scheduler noop anticipatory deadline [cfq] You can change a device's elevator on the fly by doing: # echo deadline >/sys/block/sda/queue/scheduler I'm just wondering which value gives the best performance when using software raid-1, or if the choice depends more on the type of load that's being processed. -- -Eric 'shubes' --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
Re: elevators and sw raid
On Tue, Sep 28, 2010 at 11:15 AM, Eric Shubert wrote: > Alan Dayley wrote: > >> Maybe http://www.otisworldwide.com/ ? >> >> (Sorry, couldn't resist.) >> >> Side track: What does the word "elevator" mean in the context of RAID? >> Ha! >> > > In the linux kernel, the I/O scheduler is referred to as the elevator. It > can be set to one of 4 values in the 2.6 kernel using the elevator= kernel > parameter at boot time. Each block device's scheduler is determined by the > value in /sys/block//queue/scheduler > $ cat /sys/block/sda/queue/scheduler > noop anticipatory deadline [cfq] > > You can change a device's elevator on the fly by doing: > # echo deadline >/sys/block/sda/queue/scheduler > > I'm just wondering which value gives the best performance when using > software raid-1, or if the choice depends more on the type of load that's > being processed. > > Thank you, Eric. I did not know about that kernel setting. Alan --- PLUG-discuss mailing list - PLUG-discuss@lists.plug.phoenix.az.us To subscribe, unsubscribe, or to change your mail settings: http://lists.PLUG.phoenix.az.us/mailman/listinfo/plug-discuss
