On Thu, 6 Dec 2007, Michael Tokarev wrote: > I come across a situation where external MD bitmaps > aren't usable on any "standard" linux distribution > unless special (non-trivial) actions are taken. > > First is a small buglet in mdadm, or two. > > It's not possible to specify --bitmap= in assemble > command line - the option seems to be ignored. But > it's honored when specified in config file. i think neil fixed this at some point -- i ran into it / reported essentially the same problems here a while ago. > The thing is that when a external bitmap is being used > for an array, and that bitmap resides on another filesystem, > all common distributions fails to start/mount and to > shutdown/umount arrays/filesystems properly, because > all starts/stops is done in one script, and all mounts/umounts > in another, but for bitmaps to work the two should be intermixed > with each other. so i've got a debian unstable box which has uptime 402 days (to give you an idea how long ago i last tested the reboot sequence). it has raid1 root and raid5 /home. /home has an external bitmap on the root partition. i have /etc/default/mdadm set with INITRDSTART to start only the root raid1 during initrd... this manages to work out later when the external bitmap is required. but it is fragile... and i think it's only possible to get things to work with an initrd and the external bitmap on the root fs or by having custom initrd and/or rc.d scripts. -dean - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
