Re: Where to put logs in a RAUD 1+0 system
You might want to check the documentation on the raid mangler you are using, e.g under Sun RM6 RAID10 is referred to as RAID0+1, under DiskSuite AFAIR you can't RAID10 you must RAID01 etc Paul Watson wrote: > > 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 # -- 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 #
In article <4084073B.75F6DFFD@oninit.com>, Paul Watson <paul@oninit.com> wrote: > You might want to check the documentation on the raid mangler you > are using, e.g under Sun RM6 RAID10 is referred to as RAID0+1, under > DiskSuite AFAIR you can't RAID10 you must RAID01 etc Supposedly DS a.k.a SVM recognizes your RAID01 setup and changes it into RAID10 behind the scenes -- even though you define the metadevices as if they were RAID01. I've never attempted to verify this, mind. Karl
That's rather disturbing given the earlier comments. I think it may well be DiskSuite. Paul Watson <paul@oninit.com> wrote in message news:<4084073B.75F6DFFD@oninit.com>... > You might want to check the documentation on the raid mangler you > are using, e.g under Sun RM6 RAID10 is referred to as RAID0+1, under > DiskSuite AFAIR you can't RAID10 you must RAID01 etc