On Sep 11, 2008, at 5:16 PM, A Darren Dunham wrote: > On Thu, Sep 11, 2008 at 04:28:03PM -0400, Jim Dunham wrote: >> >> On Sep 11, 2008, at 11:19 AM, A Darren Dunham wrote: >> >>> On Thu, Sep 11, 2008 at 10:33:00AM -0400, Jim Dunham wrote: >>>> The issue with any form of RAID >1, is that the instant a disk >>>> fails >>>> out of the RAID set, with the next write I/O to the remaining >>>> members >>>> of the RAID set, the failed disk (and its replica) are instantly >>>> out >>>> of sync. >>> >>> Does raidz fall into that category? >> >> Yes. The key reason is that as soon as ZFS (or other mirroring >> software) >> detects a disk failure in a RAID >1 set, it will stop writing to the >> failed disk, which also means it will also stop writing to the >> replica of >> the failed disk. From the point of view of the remote node, the >> replica >> of the failed disk is no longer being updated. >> >> Now if replication was stopped, or the primary node powered off or >> panicked, during the import of the ZFS storage pool on the secondary >> node, the replica of the failed disk must not be part of the ZFS >> storage >> pool as its data is stale. This happens automatically, since the ZFS >> metadata on the remaining disks have already given up on this >> member of >> the RAID set. > > Then I misunderstood what you were talking about. Why the restriction > on RAID >1 for your statement?
No restriction. I meant to say, RAID 1 or greater. > Even for a mirror, the data is stale and > it's removed from the active set. I thought you were talking about > block parity run across columns... > > -- > Darren > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss Jim Dunham Engineering Manager Storage Platform Software Group Sun Microsystems, Inc. work: 781-442-4042 cell: 603.724.2972 _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
