Re: Where to put logs in a RAUD 1+0 system
"Art S. Kagel" <kagel@bloomberg.net> wrote in message news:<pan.2004.04.02.08.20.02.153746.1445@bloomberg.net>... > On Thu, 01 Apr 2004 03:57:48 -0500, Andy Kent wrote: > > I mostly agree with Andy, put everything on the single RAID10 array. If the > server were to be heavily loaded with update activity then perhaps you could > make a case for reserving one pair of drives for a mirror (RAID1) to contain > just the ROOTDB and LOGSDB. But if the load will not be high, I would not > bother. > > Art S. Kagel > > PS: Remember to stripe the 5 mirrored pairs not the other way around. Hi Art, You lost me here, what exactly did you mean by "PS: Remember to stripe the 5 mirrored pairs not the other way around."? > > > I'm about to configure a brand new, fast RAID 1+0-based system which will > > use logged sbspaces. Conventional (JABOD-based) wisdom tells me to put the > > logs on a separate device to the busy storage spaces. But, on a 5-disk > > array, does this idea justify holding back one disk for the logs and just > > configuring RAID 1+0 on the other four? Is it worth it or is the idea simply > > too messy? The system will be quite lightly loaded but the sbspaces could > > make up the bulk of the activity and could actually be written more than > > read. > > > > If we went for just sticking the whole lot in a single array, is there any > > point in putting teh logs outside rootdbs? > > > > Many thanks, > > > > > > Andy Kent > > Bristol, UK > >
You want to mirror then stripe not the other way round. If you do the latter then a single disk failure on both stripes will take out the entire disk. If you mirror first the system has more redundancy. If in doubt the draw it:-)) DNix wrote: > > "Art S. Kagel" <kagel@bloomberg.net> wrote in message news:<pan.2004.04.02.08.20.02.153746.1445@bloomberg.net>... > > On Thu, 01 Apr 2004 03:57:48 -0500, Andy Kent wrote: > > > > I mostly agree with Andy, put everything on the single RAID10 array. If the > > server were to be heavily loaded with update activity then perhaps you could > > make a case for reserving one pair of drives for a mirror (RAID1) to contain > > just the ROOTDB and LOGSDB. But if the load will not be high, I would not > > bother. > > > > Art S. Kagel > > > > PS: Remember to stripe the 5 mirrored pairs not the other way around. > > Hi Art, > You lost me here, what exactly did you mean by "PS: Remember to stripe > the 5 mirrored pairs not the other way around."? > > > > > > I'm about to configure a brand new, fast RAID 1+0-based system which will > > > use logged sbspaces. Conventional (JABOD-based) wisdom tells me to put the > > > logs on a separate device to the busy storage spaces. But, on a 5-disk > > > array, does this idea justify holding back one disk for the logs and just > > > configuring RAID 1+0 on the other four? Is it worth it or is the idea simply > > > too messy? The system will be quite lightly loaded but the sbspaces could > > > make up the bulk of the activity and could actually be written more than > > > read. > > > > > > If we went for just sticking the whole lot in a single array, is there any > > > point in putting teh logs outside rootdbs? > > > > > > Many thanks, > > > > > > > > > Andy Kent > > > Bristol, UK > > > -- Paul Watson # Oninit Ltd # Growing old is mandatory Tel: +44 1436 672201 # Growing up is optional Fax: +44 1436 678693 # Mob: +44 7818 003457 # www.oninit.com #