On Sat, Mar 9, 2013 at 9:31 PM, Hugo Mills <h...@carfax.org.uk> wrote: > Some time ago, and occasionally since, we've discussed altering the > "RAID-n" terminology to change it to an "nCmSpP" format, where n is the > number of copies, m is the number of (data) devices in a stripe per copy, > and p is the number of parity devices in a stripe. > > The current kernel implementation uses as many devices as it can in the > striped modes (RAID-0, -10, -5, -6), and in this implementation, that is > written as "mS" (with a literal "m"). The mS and pP sections are omitted > if the value is 1S or 0P. > > The magic look-up table for old-style / new-style is: > > single 1C (or omitted, in btrfs fi df output) > RAID-0 1CmS > RAID-1 2C > DUP 2CD > RAID-10 2CmS > RAID-5 1CmS1P > RAID-6 1CmS2P > > The following patch set modifies userspace tools to accept C/S/P formats > in input (mkfs and the restriper). The older formats are also accepted. It > also prints the newer formats by default in btrfs fi df, with an option to > show the older format for the traditionalists. > > I'm not sure whether we should omit the 1C in btrfs fi df output, or > make it explicit even in the "single" case. > > Hugo. > > Hugo Mills (5): > Use nCmSpP format for mkfs > Move parse_profile to utils.c > Convert balance filter parser to use common nCmSpP replication-level > parser > Change output of btrfs fi df to report new (or old) RAID names > Add man page description for nCmSpP replication levels > > cmds-balance.c | 23 +++------ > cmds-filesystem.c | 135 > +++++++++++++++++++++++++++++++++++++++++++-------- > man/btrfs.8.in | 9 ++++ > man/mkfs.btrfs.8.in | 24 ++++++++- > mkfs.c | 35 ++++--------- > utils.c | 94 +++++++++++++++++++++++++++++++++++ > utils.h | 1 + > 7 files changed, 258 insertions(+), 63 deletions(-) > > -- > 1.7.10.4 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majord...@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html
I vote make it explicit to give people a chance to understand the new way it works even with just one device. The idea for this new naming scheme is great, I like it!! Will btrfs allow for things like 2C10SP2 too? Basically two RAID6 arrays with 12 drives each (10 for data, 2 for parity), if I understand it right with the entire array being mirrored to another one. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
