I have a few machines with Raid 5 with LVM on top. Here is what I can share with you. You must have grub2 installed ( I believe it is default now but I always specify when installing.) your ARRAY info from mdadm -D --scan must be in your /etc/mdadm/mdadm.conf file and be accurate. When I change something, I make sure /boot/grub/device.map is accurate and up to date. I make initrd is up to date. I then run update-grub2. then I run : for i in a b c d e (for whatever drives you have); do install-grub /dev/sd$(echo $i) done
This makes sure the grub image file is installed and updated on whatever drive is the boot drive. I have run into problems with DOS compatible partitions. To overcome this I don't use DOS compatibility in fdisk anymore and use sectors for partitioning. So far works wonderfully and I don't have to have /boot separate. I have run into one instance where I couldn't boot that I haven't figured out yet. It was on a 10 disk array I was hobbling together for a SAN/NAS but just gave up and put the OS on a separate disk and now it is booting. Before I put it on the seperate disk, I did discover that some of the disk where not showing to grub from the grub emergency CL. I think one or two of the disk controllers wasn't showing. Oh and one instance that required a complete removal and install of grub for it to boot properly. If you aren't hacking stuff together much and making a lot of changes, you shouldn't have a problem. Shane On Sat, Sep 1, 2012 at 3:58 PM, Mark Allums <m...@allums.com> wrote: > On 9/1/2012 4:46 PM, Hendrik Boom wrote: > >> On Sat, 01 Sep 2012 16:02:54 -0500, Mark Allums wrote: >> >> On 9/1/2012 3:17 PM, Hendrik Boom wrote: >>> >>>> Can squeeze boot when / is on an LVM over RAID1? >>>> >>>> Can it boot if /boot is on the LVM over RAID1? >>>> >>>> Or when /boot is on a nonRAID nonLVM partition but / is on an LVM over >>>> RAID? >>>> >>>> Context: I have to remove the hard drive my / is on. The available >>>> space to move it to is on a RAID drive. >>>> >>>> The disks carrying the RAID also have small nonRAID nonLVM partitions >>>> that would be big enough for /boot, but not all of / >>>> >>>> -- hendrik >>>> >>> >>> >>> The usual practice is to put everything except /boot on LVM. /boot can >>> theoretically go on LVM too, but it's simpler to leave it out/off of >>> LVM. /boot can go on RAID, easily, though, and I always put it on a >>> RAID 1 partition. >>> >>> So, yes, squeeze can boot with / on LVM, whether over RAID or otherwise. >>> >>> Mark >>> >> >> Thanks. Will try it in the next few days. Will also install grub to the >> MBR of all my disks, so whichever gets picked at boot time will work. >> >> Is there an eaasy way to do this, so that they'll all get updated as >> necessary when aptitude installs a new kernel? Or it this not something >> that the MBR cares about? >> >> And is th association of, say, /dev/sdb with a particular hard drive >> consistent if there's no change in hardware, or does it depend on random >> boot-tine timing issues? >> >> - hendrik >> >> >> > As Tom H mentioned, on standard Squeeze, not partitioned RAID. Sorry for > the confusion. > > You should use UUIDs or labels if you wand to reliably always boot or > mount a particular partition. The /dev/sdx designations are subject to the > winds of variability in a system, and it apparently has been deemed > unnecessary to sort this out, since UUIDs and labels are available. > > Some distributions are smart enough to write the MBR to all disks in a > RAID 1, and others are not. I don't recall if Squeeze will or won't, or or > if Wheezy will, for that matter. I haven't installed either recently > enough to need to find out. > > Anybody else know? > > Mark > > > > -- > To UNSUBSCRIBE, email to > debian-user-REQUEST@lists.**debian.org<debian-user-requ...@lists.debian.org>with > a subject of "unsubscribe". Trouble? Contact > listmas...@lists.debian.org > Archive: > http://lists.debian.org/**50428500.7020...@allums.com<http://lists.debian.org/50428500.7020...@allums.com> > > -- Shane D. Johnson IT Administrator Rasmussen Equipment
