On Aug 28, 2014, at 12:37 PM, Lars E. Pettersson <lars@xxxxxxxx> wrote: > On 08/28/14 20:21, Bruno Wolff III wrote: >> On Thu, Aug 28, 2014 at 11:10:54 -0700, >> Rick Stevens <ricks@xxxxxxxxxxxxxx> wrote: >>> >>> I think you need to reserve some small space on all the drives (and >>> with 3TB drives you can afford to sacrifice a few MB), use the remainder >>> as your RAID, and let the system put the boot partition in that reserved >>> space on the primary drive (the one the BIOS sees as the boot drive). >> >> I think using raid 1 (with the 1.0 header format) can work well for >> that. There can still grub issues with having a boot just work, but at >> least you have the stuff you need available. > > Yes, that was my intention, raid1 for /boot and raid6 for / Accidentally I set /boot also to raid6 :) But that can be fixed. Or do n-way raid1, which will cause /boot to have as many copies as you add member devices. > > On my old system I use 1TB disks, with /boot as raid1, and grub boot-loader installed on all disks. On that one I can boot the system from any of disks. Which is quite handy. That's still possible whether /boot is raid1 (n-way or mirror), or raid6. Anaconda will run grub2-install against all member devices that have a /boot member device (or at least it should, I have recently done 2 drive testing on this). Post install you can grep -i grub2-install /var/log/anaconda/program.log And it will show you the command used. It should list all member devices. So long as each member drive has a BIOS Boot partition, grub2-install will find it automatically and insert core.img there, as well as the specific jump code in the first 440 bytes of the (protective) MBR to find it. > The problem here seem to be that due to the disks being large (larger than 1TB) they are setup as GPT (GUID Partition Table), and they then also need a BIOS boot partition to work on non UEFI based systems (if I have understood it correctly). MBR partition entries are 32-bit so they're limited to 2TB. There's a small advantage to using GPT in that there's a backup header and table. So long as your BIOS doesn't get fussy with GPT, it's fine to use it even on 1TB drives, but it's not necessary. > So, to be able to boot from any of the disks, I need a BIOS boot partition on all disks, but anaconda seem to only install it on one of the disks (i.e. I want the exactly identical partition tables on all disks). It's messy. Again the installer should leave the user out of this entirely. You don't need a BIOS Boot that's exactly 1MB in size, so if you don't want to start from scratch but there's at least 100K free space on each member drive, you can create a BIOS boot there and then rerun grub2-install against all the drives, e.g.: grub2-install /dev/sd[abcde] To know for sure how big of a BIOS Boot you need: ls -lh /boot/grub2/i386-pc/core.img Mine's 26KB, as my boot fs is XFS, without LVM or raid. Yours will be a bit bigger to include mdraid1x.mod and raid6rec.mod and anything else that gets pulled in. I bet it's much less than 100K actually. Chris Murphy -- users mailing list users@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe or change subscription options: https://admin.fedoraproject.org/mailman/listinfo/users Fedora Code of Conduct: http://fedoraproject.org/code-of-conduct Guidelines: http://fedoraproject.org/wiki/Mailing_list_guidelines Have a question? Ask away: http://ask.fedoraproject.org
