Degraded for raid 5

[fung bing kwan]

Dear all

My server is using a raid-5 (SWXCR RAID Controller) system (with tru64 and version hp unix 4.0). Before a week ago, after reboot the system, a harddisk seem was died. And I cannot mount the corresponding point. The whole Oracle db cannot be started which was located at such harddisk. It reported that the system was degraded. I was quite confusing that why only a harddisk was failed and caused the system availability failed ? (The mount point still exist, but there is nothing inside). And, what if I put another new harddisk to replace the bad one? Because other db is still running within the past week. Is the raid-5 system can re-build by itself even though there is a week time gap?

Thanks in advanced !!

Kwan
16 June 2005

[Raj_75]

Hello Kwan,

If you have RAID 5 installed and only one drive failed you can replace it without data loss. Data will be rebuilt in to the new drive using parity information in other drives.

[Mahesh Kumar Malik]

Hi

Single disk failure in RAID5 should not have any impact on your operations, unless RAID controller has also mal functioned and lost RAID configuration. In such case, its configuration can be refreshed using RAID utility available in system, system can be tested & then failed disk can be replaced.

Regards
Mahesh

[JohnYu]

A failure hard disk in RAID-5 shall not influence the system function, the only impact is the RAID is degraded, i.e., no more failure protection.

The system shall work without problem in RAID-0 mode as long as you don't have another HD failure.

The system can be back to RAID-5 mode as soon as you insert a new HD and re-build the RAID system.

I don't remember whether the system can re-build by itself or you have to set the re-build command through RAID configuration utility.

I just have one HD failure in my RAID-5 system. The system continue works while I am waiting the new HD from HP. After reciving the new HD from HP, the system back to RAID-5 mode without any problem.