On Mon, 2006-10-02 at 13:10 -0700, Scott Silva wrote:
Les Mikesell spake the following on 9/29/2006 11:48 AM:
On Fri, 2006-09-29 at 13:23 -0500, rado wrote:
so close yet so far or maybe that's just the way it is, I am dumb on it but gettin smarter.
the 2 ide drives diff channels of course hda and hdc each w/3 partitions hda1 2 3 hdc1 2 3.
I format hot add sda1 2 3 cat /proc/mdstat it's all there
Unless you created it with 3 members, the 3rd is added as a spare.
...# mdadm /dev/md0 1 2 -f /dev/hdc1 2 3 (fail or fault hdc
md automatically picks up sda from spare status and writes to it.
it finishes mind you hdc is still under fail status and I reboot.
when the sys comes back up, it does not pick up sda anymore but instead just runs -U on all 3 partitions
You can add /dev/hdc1 back if it didn't resync automatically.
I was under the impression that sda would be there either I missed a step somewhere or something strange going on
I don't think usb/firewire is detected early enough to be included in the raid assembly at bootup. That's why I set mine up to use 2 internal drives all the time but only periodically sync to the external drives that are then rotated offsite. And if you want to be sure everything is clean on the copy, you should stop any processes running on the mounted partition, and unmount the mount point momentarily while you fail the disk. If you don't, the contents would be the same as if the machine had crashed - probably still usable, but it could have problems.
Maybe I am too far down the message tree to get this, but I don't see how taking one drive from a raid 5 array off site does any good. One drive on a mirror gives you a backup. One drive in a raid5 just gives you a used hard drive with not much possibility to recover anything.
We talking raid 1 Scott. It actually serves a duel purpose. It's part of a backup scheme plus it's a bootable disk image
But feel free to slap some sense into me if I am too far off. I could see if you had a raid 5 array, and then mirrored that to a raid 1 with the usb drive opposite the "entire" raid5 array you would have a viable backup. But you could just as easily mount the drive and rsync to it to get the same effect.