We recently ran into a customer who was using two older seagate drives that we no longer utilize due to high failure rates. One of the drives had went and we figured we ought to just replace both drives and get them on our more reliable Western Digital counter parts. During the process we broke the mirror and yanked one of the seagate drives replacing it with a Western Digital. We then mirrored the partitions between the Seagate and WD drive. Thinking this would be enough as the drives should be replicated identically the Seagate was removed and another WD Drive was inserted. Unfortunately this did not prove to be enough as we were continually stopped from booting the machine fully. The following is the steps I utilized to correct this matter:
1) Replaced the Seagate Drive so that the server would be bootable
2) Ensure that the drive mirrors are synced
3) From start type ‘msconfig’ to open up System Configuration
4) Click into the boot tab and select Windows Secondary Plex
5) Click on ‘Set Default’ and verify that Default OS shows up next to this in the window.
From here it will prompt you to reboot the server which is alright, I went ahead and shut the machine off and yanked the Seagate drive and tested booting off of the secondary plex before proceeding with adding the WD drive back in though this should not be necessary. The server booted successfully so I rebooted once more, added the WD Drive and mirrored them once fully booted again.