Re: GPT + RAID + boot
Sven Hartge writes: PaulNM writes: Thank you both for your help -- your suggestions were exactly what I needed (I delayed responding until I was confident I had everything working). I'm puzzled as to why parted refers to these partition types as "flags" -- seeing that when using the program, and when reading the documentation, coupled with the fact that bios_grub doesn't turn up in the man page (but only in info), and that disks using MBR actually can have a boot flag on a partition, certainly helped send me off in the wrong direction! But again, thank you both for helping me navigate through this one. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/1b8uuh5aas@snowball.wb.pfeifferfamily.net
Re: GPT + RAID + boot
Joe Pfeiffer wrote: > My goal here is to be able to have a bootable, running system in the > event of a disk failure. I've been running two disks in a RAID-1 > configuration, with grub installed on both disks, for some time. My > /etc/mdadm/mdadm.conf is essentially empty, as mdadm has been > successfully finding my RAID partitions and assembling my arrays at > boot time without it. > I've gotten a new 3TB disk (to replacing an old, failing disk), so I'm > setting up my first GPT partition table. > On my old (MBR) disk, parted shows my first partition as > 1 32.3kB 1500GB 1500GB primary boot, raid > and I'm able to boot successfully. > On my new (GPT) disk, I am only able to install grub if I've set the > bios_grub flag (note that this flag doesn't appear in the man page, > though it does appear in the documentaiton at > http://www.gnu.org/software/parted/manual/parted.html#set) on my > partition. If I set the boot or legacy_boot flags, I get > snowball:518$ sudo grub-install /dev/sdb > /usr/sbin/grub-setup: warn: This GPT partition label has no BIOS Boot > Partition; embedding won't be possible!. > /usr/sbin/grub-setup: error: embedding is not possible, but this is required > for cross-disk install. > Unfortunately, I don't seem to be able to set both the bios_grub and > the raid flags at the same time. If I set the bios_grub flag, > printing the partition table shows no raid flag; if I set the raid > flag, printing the partition table shows no bios_grub flag. Attention! Don't EVER set the bios_grub flag on ANY partition not specially added to be a "BIOS Boot Partition". If you add this flag to your main data partition, installing GRUB _WILL_ destroy the data on this partition by overwriting it. The "BIOS Boot Partition" is a replacement for the empty sectors 1 to 62 GRUB uses with an MBR-based disk layout to embed its stage 1.5. Those sectors are used with the GPT and thus you need a specially created place to put the initial stages of GRUB. Solution: Create a small (1MiB is enough) separate partition on _each_ of your disks and then continue to install GRUB via "grub-install /dev/sdX" as you would do with a MBR-based disk. (To be safe, be sure to create this little partition below 2TiB.) S° -- Sigmentation fault. Core dumped. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/dabmmeil9...@mids.svenhartge.de
Re: GPT + RAID + boot
On 01/07/2014 03:20 PM, Joe Pfeiffer wrote: snip > > Booting with the bios_grub flag set, my raid array isn't assembled > properly: the partition with bios_grub set isn't added into the array > (fortunately, my other disk is good!). > > So: how can I go about setting up my new disk so I will have a two-disk > RAID array if both disks are good, and be able to boot with a degraded > array in the event of either disk failing? > Well, bios_grub and raid aren't flags. They're partition types. The gpt layout doesn't have as much spare room in it as the older mbr. Creating a small bios_grub partition gives some space for grub to install parts of itself. You need to create a small (recommend 1MB) partition for bios_grub, then the rest of the drive can be a linux raid partition. - PaulNM -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/52cc79c5.6010...@paulscrap.com
GPT + RAID + boot
My goal here is to be able to have a bootable, running system in the event of a disk failure. I've been running two disks in a RAID-1 configuration, with grub installed on both disks, for some time. My /etc/mdadm/mdadm.conf is essentially empty, as mdadm has been successfully finding my RAID partitions and assembling my arrays at boot time without it. I've gotten a new 3TB disk (to replacing an old, failing disk), so I'm setting up my first GPT partition table. On my old (MBR) disk, parted shows my first partition as 1 32.3kB 1500GB 1500GB primary boot, raid and I'm able to boot successfully. On my new (GPT) disk, I am only able to install grub if I've set the bios_grub flag (note that this flag doesn't appear in the man page, though it does appear in the documentaiton at http://www.gnu.org/software/parted/manual/parted.html#set) on my partition. If I set the boot or legacy_boot flags, I get snowball:518$ sudo grub-install /dev/sdb /usr/sbin/grub-setup: warn: This GPT partition label has no BIOS Boot Partition; embedding won't be possible!. /usr/sbin/grub-setup: error: embedding is not possible, but this is required for cross-disk install. Unfortunately, I don't seem to be able to set both the bios_grub and the raid flags at the same time. If I set the bios_grub flag, printing the partition table shows no raid flag; if I set the raid flag, printing the partition table shows no bios_grub flag. Booting with the bios_grub flag set, my raid array isn't assembled properly: the partition with bios_grub set isn't added into the array (fortunately, my other disk is good!). So: how can I go about setting up my new disk so I will have a two-disk RAID array if both disks are good, and be able to boot with a degraded array in the event of either disk failing? -- "Erwin, have you seen the cat?" -- Mrs. Shroedinger -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/1bfvoz35op@snowball.wb.pfeifferfamily.net
