Re: question on vinum

From: Chuck Swiger (cswiger_at_mac.com)
Date: 10/27/04

  • Next message: Dave Horsfall: "Re: question on vinum" 
    Date: Wed, 27 Oct 2004 08:05:10 -0400
To: miha@ghuug.org

    Mikhail P. wrote:
    > On Wednesday 27 October 2004 05:33, secmgr wrote:
    [ ... ]
    >> If you want to do that, then you want raid5. If either a concat or
    >> stripe set looses a drive, the data will need to be restored.
    >
    > Are there known methods/techniques to restore data from failed concat or
    > stripe volumes?

    Certainly. It's known as "taking a backup", perhaps to a tape drive or some
    other form of storage. If you don't have a backup, and you lose a disk in a
    RAID-0 config, you will effectively lose all of the data.

    [ ... ]
    > Does striping require an additional drive too?

    No.

    > Or it is very similar to
    > concat, except for it stores data across all the spindles?

    Yes, that's right.

    > Does it also mean that it is harder to recover stripped volume?

    The question isn't well-phrased: you can't recover data from either if you
    lose a drive.

    > As for raid5 - it requires an additional drive. Are there any requirements for
    > the drive? E.g. would it work as having 3 x 200GB for stripe + additional
    > 20GB drive that will be used for control blocks?

    No. All of the drives need to be the same size. With RAID-5, which drive is
    used to hold parity data rotates on a stripe-by-stripe basis to balance out
    the load.

    > And what happens here if
    > 20GB drive fails - will I be able to rebuild it and continue using raid?

    You can rebuild a RAID-5 volume if a single drive fails without losing data. 

    -- 
-Chuck
_______________________________________________
freebsd-stable@freebsd.org mailing list
http://lists.freebsd.org/mailman/listinfo/freebsd-stable
To unsubscribe, send any mail to "freebsd-stable-unsubscribe@freebsd.org"
  • Next message: Dave Horsfall: "Re: question on vinum"

    Relevant Pages