On Mon, Jun 30, 2008 at 11:43 AM, Akhilesh Mritunjai <[EMAIL PROTECTED]> wrote: >> I'll probably be having 16 Seagate 15K5 SAS disks, >> 150 GB each. Two in HW raid1 for the OS, two in HW >> raid 1 or 10 for the transaction log. The OS does not >> need to be on ZFS, but could be. > > Whatever you do, DO NOT mix zfs and HW RAID. > > ZFS likes to handle redundancy all by itself. It's much smarter than any HW > RAID and when does NOT like it when it detects a data corruption it can't fix > (i.e. no replicas). HW RAID's can't fix data corruption and that leads to a > very unhappy ZFS. > > Let ZFS handle all redundancy.
If you are dealing with a high-end storage array[1] that does RAID-5, you probably want to do RAID-5 on there, as well as mirroring with ZFS. This allows disk replacements to be done using only the internal paths of the array. If you push the rebuild of a 1 TB disk to the server, it causes an unnecessary amount of traffic across shared[2] components such as CHIPP processors[3], inter-switch-links, etc. Mirroring then allows zfs to have the bits needed to self-heal. 1. Typically as physically large as the combined size of your fridge, your mom's fridge, and those of your three best friends that are out of college and have a fridges significantly larger than a keg. 2. "Shared" as in one server's behavior can and may be somewhat likely to affect the performance of another. 3. Assuming Hitachi -- Mike Gerdts http://mgerdts.blogspot.com/ _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
