Michael Christie wrote:
Hi there all,I need your help. I have a supermicro server which was running Freebsd 7.1 with 2 SATA drives. I have had G mirror running on the server. I needed to do a full reinstall of freebsd but was unable to disengage the mirror at the time. When installing Freebsd, on to the drives i see i have AD4 AD6 and AR0 on the disk label, i have installed the new free bsd in AD4, and the system would not boot. I have come across this before where i have to remove AR0 to default the drive, i can remember reading a thread on how to use “fix it” and using the live cd. I have google but cannot find it
You do understand that 'ar0' is an ATARAID mirror and nothing to do with gmirror at all? gmirror uses device names like /dev/mirror/gm0 typically.
Please is there any one here that can refresh my memory and tell me how to remove gmirror from my drives so i can do a fresh install,.
You don't need to remove gmirror per-se. If you do a fresh install on top of what you have, it will set up the drive you install on as a stand-alone disk. In fact, you can take one of a gmirror'd pair and just tweak the device names in /etc/fstab and run it as a plain disk pretty easily without reinstalling at all. There will be gmirror metadata blocks on disk, but these wont have any effect unless you mount partitions on the gmirror device. To remove those metadatablocks, just do
# gmirror clear /dev/mirror/gm0 (or whatever your gmirror device is called) -- obviously *not* while the gmirror is active. You may need to allow writes to an active underlying partition by # sysctl kern.geom.debugflags=16 The ATARAID mirror you seem to have picked up inadvertently is very similar to a gmirror RAID in the way it works, except that it won't generally have the nice behaviour for replacing blown hot-swap drives without having to reboot the system.In any case, you can just ignore /dev/ar0 and mount partitions from /dev/ad4 instead, equivalently as for the gmirror case. To remove ar0, just do:
# atacontrol delete ar0 Either of these are fairly safe to do while the system is up and running. Also, I suspect that your system is not booting for a different reason than you think. You'ld have to tell us the exact error message you see in order to get a definitive answer, but given what you've described two pretty likely problems are: * Early stage boot blocks can't find the kernel image. In this case you'll be dumped at the loader prompt and asked to give the device name and path to read the kernel from -- typically something like(ad,0)/boot/kernel/kernel
(you can use the 'ls' command in the loader to see what available devices there are to try booting from). * Can't mount root partition. Generally this means that /etc/fstab contains incorrect data. In this case, you can probably boot to single user, remountthe root partition read-write and then edit /etc/fstab
These are not impossibly difficult things to deal with, but neither are they entirely trivial, and if you're a beginner and you don't care about what's currently on the disk, you might find it more productive just to reinstall over the top of the previous contents. Cheers, Matthew -- Dr Matthew J Seaman MA, D.Phil. 7 Priory Courtyard Flat 3 PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate Kent, CT11 9PW
Description: OpenPGP digital signature