All, For the last couple of days our big fileserver dakar has been down due to failure to boot correctly. The symptom is that you'd get a grub command line, no grub menu and the typical well documented manual boot commands did not work. This started from (I believe) a zpool upgrade command. This is a fairly innocuous command that just updates the on disk zpool/zfs format to match newer kernels and zfs drivers as they are released. Something went wrong. In conversing with the experts on the IRC channel(s) "thats not supposed to do that" was invoked a couple of times. I urge caution for any planned upgrades our zfs systems until this is better understood. And note: you can zpool/zfs upgrade all the data pools til the cows come home - this problem only manifests on the root pool (rpool) where latest and greatest zfs should be close to irrelevant. Its a grub/boot issue and thus only relevant on the rpool. I now know a bit more about booting solaris and will try and prepare a document later. -- Hunter Matthews Unix Administrator Office: Bldg 240 Room 2139 Argonne National Labs, MCS Key: F0F88438 / FFB5 34C0 B350 99A4 BB02 9779 A5DB 8B09 F0F8 8438 Never take candy from strangers. Especially on the internet. [Sharing with the wider group of sysadmins --Craig]