I''d like to get a concensus of how to describe ZFS RAID configs in a short-hand method. For example, single-level no RAID (1 disk) RAID-0 (dynamic stripe, > 1 disk) RAID-1 RAID-Z RAID-Z2 mutliple levels RAID-1+0 RAID-Z+0 RAID-Z2+0 Is it better to say RAID-0, striping, or dynamic striping? Is it better to say RAID-1 or mirroring? -- richard
I don''t see why you would distinguish between single-level and multiple levels. ZFS pools are always dynamically striped, I don''t see why you''d call out the degenerate case of single toplevel vdev as anything special. I would use simple terminology: Unreplicated Mirrored Single Parity RAID Double Parity RAID If people need to correlate this with traditional terminology (RAID-0, etc), then it could be placed in parentheses. But it makes more sense to take dynamic striping as a fact of life, and not differentiate a single mirror from two mirrors, etc. - Eric On Wed, Aug 09, 2006 at 02:16:40PM -0700, Richard Elling - PAE wrote:> I''d like to get a concensus of how to describe ZFS RAID configs in a > short-hand method. For example, > single-level > no RAID (1 disk) > RAID-0 (dynamic stripe, > 1 disk) > RAID-1 > RAID-Z > RAID-Z2 > > mutliple levels > RAID-1+0 > RAID-Z+0 > RAID-Z2+0 > > Is it better to say RAID-0, striping, or dynamic striping? > Is it better to say RAID-1 or mirroring? > -- richard > _______________________________________________ > zfs-discuss mailing list > zfs-discuss at opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss-- Eric Schrock, Solaris Kernel Development http://blogs.sun.com/eschrock
I''m with ya on that one. I''d even go so far as to change "single parity RAID" to "single parity block". The talk of RAID throws people off pretty easily especially when you start layering ZFS on top of things other then a JBOD. Eric Schrock wrote:> I don''t see why you would distinguish between single-level and multiple > levels. ZFS pools are always dynamically striped, I don''t see why you''d > call out the degenerate case of single toplevel vdev as anything > special. I would use simple terminology: > > Unreplicated > Mirrored > Single Parity RAID > Double Parity RAID > > If people need to correlate this with traditional terminology (RAID-0, > etc), then it could be placed in parentheses. But it makes more sense > to take dynamic striping as a fact of life, and not differentiate a > single mirror from two mirrors, etc. > > - Eric > > On Wed, Aug 09, 2006 at 02:16:40PM -0700, Richard Elling - PAE wrote: > >> I''d like to get a concensus of how to describe ZFS RAID configs in a >> short-hand method. For example, >> single-level >> no RAID (1 disk) >> RAID-0 (dynamic stripe, > 1 disk) >> RAID-1 >> RAID-Z >> RAID-Z2 >> >> mutliple levels >> RAID-1+0 >> RAID-Z+0 >> RAID-Z2+0 >> >> Is it better to say RAID-0, striping, or dynamic striping? >> Is it better to say RAID-1 or mirroring? >> -- richard
Torrey McMahon wrote:> I''m with ya on that one. I''d even go so far as to change "single parity > RAID" to "single parity block". The talk of RAID throws people off > pretty easily especially when you start layering ZFS on top of things > other then a JBOD.Agree, I still have people who think RAID == RAID-5 and get totally confused about any other description of "RAID" -- richard> Eric Schrock wrote: >> I don''t see why you would distinguish between single-level and multiple >> levels. ZFS pools are always dynamically striped, I don''t see why you''d >> call out the degenerate case of single toplevel vdev as anything >> special. I would use simple terminology: >> >> Unreplicated >> Mirrored >> Single Parity RAID >> Double Parity RAID >> >> If people need to correlate this with traditional terminology (RAID-0, >> etc), then it could be placed in parentheses. But it makes more sense >> to take dynamic striping as a fact of life, and not differentiate a >> single mirror from two mirrors, etc. >> >> - Eric >> >> On Wed, Aug 09, 2006 at 02:16:40PM -0700, Richard Elling - PAE wrote: >> >>> I''d like to get a concensus of how to describe ZFS RAID configs in a >>> short-hand method. For example, >>> single-level >>> no RAID (1 disk) >>> RAID-0 (dynamic stripe, > 1 disk) >>> RAID-1 >>> RAID-Z >>> RAID-Z2 >>> >>> mutliple levels >>> RAID-1+0 >>> RAID-Z+0 >>> RAID-Z2+0 >>> >>> Is it better to say RAID-0, striping, or dynamic striping? >>> Is it better to say RAID-1 or mirroring? >>> -- richard >