Re: Oracle and Raid5

On Thu, 17 Sep 1998 02:40:49 -0400, Em Pradhan <empradhan_at_dplus.net> wrote:

>Hi
>I have RAID 5 in one of the site and as per RAID 5 vendor if any one of the drive
>fails you can swap the disk (replace the disk with new disk) provided your parity
>protection is On. Under this condition data will be written to new disk
>automatically and for time being system will run in degraded mode.
>So far I never found any documentation to prove that . If any one have an
>experience
>that a disk can be pulled out of RAID 5 and put back in with out requiring any
>configuration
>please let me know.. also if there exists any documentation let me know pls..
>thanks (TIA)
>
>
>Craig Munday wrote:

It depends on what RAID5 box you have; *each vendor's product has different capabilities*. With HP AutoRAID you can hot swap out disks, fans, power units, and controllers. I tested disks, fans, and power units. It works as promised, no reconfiguration, no problems. The array marks all disk with a code. It knows where it was installed what condition it was in when removed. HP AutoRAID boxes can also be configured for Active Spare. The equivalent of one disk is reserved in case of a disk failure. If a disk fails, it is rebuilt from parity to the Active Spare. Once rebuilt, there is no degradation in performance. If another disk should fail before you replace the disk, disk requests are serviced from parity with reduced performance. Another disk failure, I guess that makes three, would result in data loss. If you want to see what happens when you pull out a disk, You might want to pull one out. Before you go production of course, and with a good backup. I did, it was fun and gave me piece of mind.

--
Ken Walters
kwalters_at_pbs.org
DBA
Public Braodcasting Service
kwalters_at_pbs.org Received on Thu Sep 17 1998 - 08:44:10 CDT