I have a Nexenta system that's been running fine for the last few years. Recently one of the system disks failed --- the syspool was part of a ZFS mirror.
If I configure the system's BIOS to boot from the working drive, the text GRUB ("GRUB" followed by a space) appears on the screen, and the system doesn't respond.
If I boot from a Nexenta installation CDROM and try to set the root as follows:
root (hd1,0,a)
...I get the following message from GRUB:
Filesystem type unknown, partition type 0xbf
However if I were to issue the above root command on a fresh Nexenta installation, I would see:
Filesystem type zfs, partition type 0xbf
How can I get GRUB to recognize the surviving root mirror disk, so I can boot from it? And, in the future, what procedure should I follow when a device in a root mirror fails, so that I can properly recover (and boot from any drive in the mirror pool)?
This sounds a lot like a similar issue I experienced on my Nexenta installation. I had recently done a ZFS version upgrade across both the
syspooland my other pools, but failed to re-install grub afterwards. The result was that the next power outage left grub unable to read the ZFS filesystem and the system was unbootable.There was a discussion over at Nexenta which helped me out.
Basically, I fixed it by booting from a recent Nexenta LiveCD which supported the latest ZFS version, and then running
on my syspool disk. On rebooting, the new grub could now read the disk and boot the system.