Boot MirrorDisk Fails

[Learn_1]

Just wanted to confirm that what would be the procedure when one of the system mirror disk fail(from which system has booted) and we do not have a spare one at the moment.the buddy mirror disk takes over the system and system is working.But when we go to check the disk via ioscan or go for swap info it just keep looking for these things. i wanted to know whether we will have to run any command or procedure so that system just keep working accordingly till we have the spare disk to replace it with the failed mirror disk.similarly if we reboot the system with the one mirror system disk failed the system boots properly and shows everthing according i.e. the result of the ioscan and swapinfo command.we have 2 swap partitions on the system disk and are mirrored.
So the real question is whether i will have to run any command to stabilize the system to keep functioning without rebooting in case when one mirror disk fail from which system was booted up.

[Michael Tully]

The system will run fine as long as the secondary disk does not fail. If a primary disk fails it automatically goes to the secondary. That's how mirrorDisk/UX works. If you attempt to reboot you will encounter a problem as the system will attempt to boot from your primary disk. You would need to change the primary boot disk. You can have a look at the 'setboot' from which I cam sure you can it to the secondary disk. The man page will explain it. In answer to your question, the system will run fine, and there is no need to reboot. Most of the internal disks are hot swappable these days. If it is an older model you may have to shutdown.

[David Holbrook]

Assume the original drive is C: and the mirror is on the drive the system sees as D:, to simplify the question. You must create a boot floppy , formatted unde NT, and put the boot files (boot.ini, ntdetect.com, ntldr) on this disk. Next you must go in and modify the boot.ini file on the floppy so that it points to the second drive in the mirror (D: in the example) so the system will boot to the second half of the mirror. This is boot disk only needed to boot when the primary drive fails, but is also a useful tool to verify that the second drive is still good.

If I read your question right, you have a bad drive, but can still boot, so the primary drive appears to be functioning correctly, and the problem must be with the mirror drive. Assuming this is correct, you might want to try breaking the mirror, wiping the bad part of the mirror drive, and then re-create the mirror and see if that solves the problem. I have had mirror drives get "out of sync" so to speak, which causes the mirror to show up as bad, and this has cured the issue. In any event, make sure you correctly identify which drive the problem is on before you break the mirror, and create the boot disk AND TEST IT OUT before you do anything to the mirror. Also a very good idea to have a COMPLETE backup of the drive before you do anything, just in case you make a mistake. :)

HTH

David