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RAID1 mirror repair completed

Posted: Thu Nov 13, 2014 10:36 pm
by embleton
Had a RAID1 hard disk failure, which required 1 disk to be replaced. But at this time I'm replacing both drives to extend the size of available storage. This means that over the last couple of days I've had to bring the system down for short periods whilst fitting hard drives, swapping them around and re-mirroring.

Sorry for the inconvenience if you've attempted to access the forums during any of these short outages. There will be a short outage tomorrow morning whilst I swap a disk around, this should then be the end of essential maintenance.

By the Board Administrator.

Re: RAID1 mirror repair completed

Posted: Fri Nov 14, 2014 3:47 pm
by embleton
Scheduled RAID1 both disks mirrored and extended to 2TB. Data was intact throughout this unscheduled and scheduled maintenance, downtime was minimal.

Re: RAID1 mirror repair completed

Posted: Sat Nov 15, 2014 4:10 am
by embleton
The Dell XPS-435MT RAID controller allows any disk to be moved around to any SATA port to maintain the mirror. Any disk that is larger than a current RAID1 disk can replace a faulty hard disk, but its advisable to re-mirror to a larger disk then replace the 2nd hard disk with the same size, type and firmware release so you have good integrity in the new RAID1 mirror.

The process is as follows:-

1. Identify faulty disk by unplugging each disk in turn until the computer fires up.
2. Replace the faulty disk with a new disk that is greater in size then that being replaced.
3. Mirror to the larger disk of the RAID1 pair from the old good disk in the pair.
4. Replace the old good disk with a 2nd hard disk with same characteristics as the replacement in 2.
5. Mirror to the 2nd disk of the same characteristics as a replacement in 2.
6. Increase the size of the RAID1 mirror and wait until that's complete.
7. Extend the last partition by available free space once the computer has been rebooted.

The process takes approximately 12 hours for each TB in the mirror, and the computer needs rebooting during each part replacement and extending size of RAID1 mirror. At each stage, you should only encounter downtime of about a couple minutes during each reboot. The system will be up and running during re-mirroring and extend the size of the RAID1 mirror. And you will not encounter any data loss during this complete process.