On Thursday October 1, bendj095124367913213465@xxxxxxxxx wrote: > I'm setting up new linux boxes, hoping to install whatever OS I choose > to a software RAID array. > > I've got 4 identical SATA drives, and would ideally like to use RAID-10. > > I've read a bunch of slightly stale How-To docs, and have a few questions. > > (1) Can Linux boot from /boot on RAID-10? Oldest info I found said no > boot from RAID at all, then more recent docs said boot from RAID-1 > works. I found nothing on RAID-10. What's the latest sccop on this? Linux doesn't boot. Something else has to boot Linux. So the question really is: Can Lilo, or grub, or grub2 or whatever boot on RAID-10. It is possible that grub2 can or will be able to one day, but I think the safest answer to work with at the moment is "no". > > (2) As far as I can tell, none of the installers in Centos, Ubuntu or > Opensuse are RAID-10 aware. Seems like the sanest way to get setup > would be to boot from SystemRescueCD, do the partitioning and RAID > creation, then re-boot from an installer disk using the pre-setup > disks. > > Am I missing some other, simpler approach? I haven't used any of those installers in ages but I wouldn't be surprised if what you say is true. Your "sanest way" suggestion is the approach that I would probably take. > > (3) Assuming that I'll have to boot from RAID-1 (Just suspect that > RAID-10 is not yet an option for /boot, but willing to be shown > wrong!), I'm considering 3 partitioning/raid_config options, > > (a) > DISK1 DISK2 DISK3 DISK4 > [ RAID-1 /boot ] > [ RAID-1 swap ] > [ RAID-10 LVM, /root & 'other' parts ] > > (b) > DISK1 DISK2 DISK3 DISK4 > [ RAID-1 /boot ] [ RAID-1 swap ] > [ RAID-10 LVM, /root & 'other' parts ] > > (c) > DISK1 DISK2 DISK3 DISK4 > [ RAID-1 /boot ] > [ RAID-10 LVM, /root, swap & 'other' ] > > Are there any clear benefits/concerns of one config over the other? I would probably go for 'c' as it is most flexible. If, however, you are going to be hitting swap a lot, and cannot afford extra memory, 'a' might be the better option. It isn't really a lot between them. > > (4) In setting up the RAID arrays, I've got a choice of metadata > versions. It seems that the distros' installers default to "1.0", but > that "1.1" & "1.2" are both available, too. > > Should I just use the newest, 1.2? Any problems if I do? 1.2 isn't "newer". 1.0, 1.1, 1.2 are similar but put the metadata in different places. I has been suggested that we call them 1.end, 1.start and 1.offset (or something like that) and while it might be a good idea, it hasn't happened. You almost certainly want 1.0 for /boot otherwise you probably won't be able to boot. I would suggest 1.1 for your RAID10. > > (5) In whatever config is "best" in (3), above, is it still good > advice to install the bootlader into multiple MBRs? For example, if I > extend the RAID-1 over all 4-disks, then, I install the loader into > all four MBRs? Yes. Else you might be able to boot if the first device dies. Good luck, NeilBrown -- 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
