On Sun, 12 Aug 2012 15:17:09 -0700 Jake Thomas <thomasj10@xxxxxxxxxxxxx> wrote: > CC to linux-raid mailing list: > > Hi Neil! > > Sorry for the delayed response. I kept checking on my iPhone for a > response, and for some reason or lack thereof didn't see it. I figured > that I'd have to wait a few days for my post to go through. I started > checking over here everyday and never got a response: > http://marc.info/?l=linux-raid&m=134415164808677&w=2 . I guess I > neglected this blog. And I was out camping for a few days. > > When I do "sudo /sbin/mdadm.moved -D /dev/md127" after startup > (before it's working), it says: > > mdadm: md device /dev/md127 does not appear to be active. > > (I now moved /sbin/mdadm.moved back to /sbin/mdadm for ease of use.) > > When I do "sudo mdadm --misc --query /dev/md127", I get: > > /dev/md127: is an md device which is not active > > > I found out that I can do: > > "sudo mdadm -R /dev/md127" and that starts it up just fine and > everything is good again. (Don't have to stop it or anything.) > > I can then do: > sudo mdadm /dev/md127 -a /dev/ram0. > > However, the problem still remains that it is not started on start-up, > thus I cannot have /usr be such a raid device, which needs to be > mounted very early in startup, before any scripts get ran. Therefore I > can't just put "mdadm -R /dev/md127" in a script somewhere to fix the > issue. I even tried the raid=autodetect option at the kernel > parameters line (And yes, "mdadm_udev" was in the HOOKS line in > mkinitcpio.conf and "md_mod" and "raid0" were in the MODULES line in > mkinitcpio.conf when I built the initial ramdisk with mkinitcpio.) > I also tried doing "md=1,/dev/sda2" at the kernel line, which was > ignored, because /dev/md1 was not created. Instead, I got the regular > /dev/md127 (which is not active). Also tried "md=1,/dev/sda2,missing". > Same result. Also tried "md=1,/dev/sda2,/dev/ram0". Same result. Also > tried "md=1,/dev/ram0,/dev/sda2". Same result. Also tried > "md=1,missing,/dev/sda2". Same result. > I also tried md-mod.start_dirty_degraded=1. Still wasn't active on startup. > > After running the above two commands (before the kernel parameters > paragraph) to get the raid device going, "sudo mdadm -D /dev/md127" > gives: > /dev/md127: > Version : 1.2 > Creation Time : Wed Aug 1 19:33:20 2012 > Raid Level : raid1 > Array Size : 3144692 (3.00 GiB 3.22 GB) > Used Dev Size : 3144692 (3.00 GiB 3.22 GB) > Raid Devices : 2 > Total Devices : 2 > Persistence : Superblock is persistent > > Update Time : Sun Aug 12 13:39:56 2012 > State : clean, degraded, recovering > Active Devices : 1 > Working Devices : 2 > Failed Devices : 0 > Spare Devices : 1 > > Rebuild Status : 9% complete > > Name : archbang:0 > UUID : 31f0bda6:4cd69924:46a0e3b2:4f7e32ba > Events : 166 > > Number Major Minor RaidDevice State > 2 1 0 0 spare rebuilding /dev/ram0 > 1 8 2 1 active sync writemostly /dev/sda2 > > > Also, when I first startup, if I do: > sudo mdadm --manage /dev/md127 --remove /dev/sda2 > > I get: > mdadm: cannot get array info for /dev/md127 > > And if I do: > sudo mdadm --manage /dev/md* --remove /dev/sda2 > > I get: > mdadm: Must give one of -a/-r/-f for subsequent devices at /dev/md127 > > What's going on with the above two command outputs? > > > I will put a copy of this reply here: > http://marc.info/?l=linux-raid&m=134415164808677&w=2 > > For those of you looking at the linux-raid mailing list, I am coming > from here: http://neil.brown.name/blog/20120615073245 . > > The idea of RAID1ing with a ramdisk came from > here:https://bbs.archlinux.org/viewtopic.php?pid=493773#p493773 . If you ask a question on the blog, you get a reply on the blog. If you ask a question on linux-raid you get a reply on linux-raid.... If you ask on both.... :-) The array isn't starting at boot time because it is degraded. This suggests a problem with the boot scripts. I suspect your distro ('arch'?) is relying on "mdadm -I" being run from udev to start the arrays. This by itself isn't always enough. After all devices have been discovered you need "mdadm -Irs" or "mdadm --incremental --run --scan" to assemble any newly-degraded arrays. So in some script before it tries to mount filesystems you want something like: udevadm settle mdadm --incremental --run --scan This will have to go in a script in the initrd of course. NeilBrown
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