Re: [gentoo-user] How does grub assemble a RAID1 for / ??
Try appending md=3,/dev/sdb3,/dev/sdc3 to the kernel command line parameters. On 04/04/2010 01:45 AM, Albert Hopkins wrote: On Sat, 2010-04-03 at 16:07 -0700, Mark Knecht wrote: The install is complete but it won't boot. grub finds the kernel and starts booting but then I get the typical VFS file sync error as the kernel starts looking for the install on /dev/md3. What I'm not understanding is how does the boot process get the information required to assemble the RAID device. GRUB does not assemble raid. That's why it only works with RAID1. By your own account, GRUB has succeeded, therefore GRUB is not the problem. The problem is the kernel The kernel assembles RAID by looking for partitions of with the Linux RAID partition type, finding out what kind of RAID they are, and assembling them (according to their RAID volume UUID). You apparently only have one RAID volume. It's probably being assigned to /dev/md0, yet you are passing root=/dev/md3.. not sure why you are doing that. -- Xavier Parizet YaGB : http://gentooist.com GPG :C7DC B10E FC21 63BE B453 D239 F6E6 DF65 1569 91BF signature.asc Description: OpenPGP digital signature
Re: [gentoo-user] How does grub assemble a RAID1 for / ??
On Sun, Apr 4, 2010 at 2:57 AM, Xavier Parizet x...@gentooist.com wrote: Try appending md=3,/dev/sdb3,/dev/sdc3 to the kernel command line parameters. Thanks. Tried that one last night but no luck, although it does change the message to Unknown-block(9,3) from Unknown-block(9,0). Cheers, Mark
Re: [gentoo-user] How does grub assemble a RAID1 for / ??
On Sat, 3 Apr 2010 16:07:06 -0700, Mark Knecht wrote: The install is complete but it won't boot. grub finds the kernel and starts booting but then I get the typical VFS file sync error as the kernel starts looking for the install on /dev/md3. What I'm not understanding is how does the boot process get the information required to assemble the RAID device. By hand in the non-RAID install I do this: keeper ~ # mdadm -A /dev/md3 /dev/sdb3 /dev/sdc3 mdadm: /dev/md3 has been started with 2 drives. keeper ~ # cat /proc/mdstat Personalities : [raid1] md3 : active raid1 sdb3[0] sdc3[1] 52436092 blocks super 1.1 [2/2] [UU] unused devices: none keeper ~ # but when I try to boot the RAID install it says it cannot find /dev/md3. You need to set the partition type for the RAIDed partitions to Linux raid autodetect. You'll probably then find that the kernel sets the RAID as /dev/md0, not md3. -- Neil Bothwick You want us to do WHAT? - Ancient Chinese wall engineer. signature.asc Description: PGP signature
Re: [gentoo-user] How does grub assemble a RAID1 for / ??
On Sat, 2010-04-03 at 16:07 -0700, Mark Knecht wrote: The install is complete but it won't boot. grub finds the kernel and starts booting but then I get the typical VFS file sync error as the kernel starts looking for the install on /dev/md3. What I'm not understanding is how does the boot process get the information required to assemble the RAID device. GRUB does not assemble raid. That's why it only works with RAID1. By your own account, GRUB has succeeded, therefore GRUB is not the problem. The problem is the kernel The kernel assembles RAID by looking for partitions of with the Linux RAID partition type, finding out what kind of RAID they are, and assembling them (according to their RAID volume UUID). You apparently only have one RAID volume. It's probably being assigned to /dev/md0, yet you are passing root=/dev/md3.. not sure why you are doing that.
Re: [gentoo-user] How does grub assemble a RAID1 for / ??
On Sat, Apr 3, 2010 at 4:37 PM, Neil Bothwick n...@digimed.co.uk wrote: On Sat, 3 Apr 2010 16:07:06 -0700, Mark Knecht wrote: The install is complete but it won't boot. grub finds the kernel and starts booting but then I get the typical VFS file sync error as the kernel starts looking for the install on /dev/md3. What I'm not understanding is how does the boot process get the information required to assemble the RAID device. By hand in the non-RAID install I do this: keeper ~ # mdadm -A /dev/md3 /dev/sdb3 /dev/sdc3 mdadm: /dev/md3 has been started with 2 drives. keeper ~ # cat /proc/mdstat Personalities : [raid1] md3 : active raid1 sdb3[0] sdc3[1] 52436092 blocks super 1.1 [2/2] [UU] unused devices: none keeper ~ # but when I try to boot the RAID install it says it cannot find /dev/md3. You need to set the partition type for the RAIDed partitions to Linux raid autodetect. You'll probably then find that the kernel sets the RAID as /dev/md0, not md3. -- Neil Bothwick Tried changing root=/dev/md0. No change. The actual failure message is the fairly standard VFS - Unable to mount root fs on unknown-block(9,0) I can control this using (for instance) title /dev/sda1 Gentoo Linux 2.6.33-gentoo-RAID root (hd0,0) kernel (hd0,0)/boot/bzImage-2.6.33-gentoo-RAID root=/dev/md3 md=3,1,/dev/sdb3,/dev/sdc3 which changes the message to 'unknown-block(9,3)' Since the mknod command for md devices is always 9 1 or 9 3 those match up. Is this saying that the special file thing for 9,0 and 9,3 are missing at boot time? As I posted in the first post the partitions are marked as autodetect, but if it matters I did that late in the process after the RAID was built. keeper ~ # fdisk -l /dev/sdb /dev/sdc Disk /dev/sdb: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0xa06ef201 Device Boot Start End Blocks Id System /dev/sdb1 1 14 112423+ 83 Linux /dev/sdb2 16 538 4200997+ 82 Linux swap / Solaris /dev/sdb3 544707152436160 fd Linux raid autodetect Disk /dev/sdc: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Disk identifier: 0x2ab15637 Device Boot Start End Blocks Id System /dev/sdc1 1 14 112423+ 83 Linux /dev/sdc2 16 538 4200997+ 82 Linux swap / Solaris /dev/sdc3 544707152436160 fd Linux raid autodetect keeper ~ # Answering Albert - I did it with /dev/md3 because that's how the install guide did it: mknod /dev/md3 b 9 3 mdadm --create /dev/md3 --level=1 --raid-devices=2 /dev/sda3 /dev/sdb3 From fstab: /dev/md3 / ext3 noatime 0 1 From grub.conf: title Gentoo root (hd0,0) kernel /boot/kernel root=/dev/md3 Granted, my kernel line is a little different: root (hd0,0) kernel (hd0,0)/boot/bzImage-2.6.33-gentoo-RAID root=/dev/md3 but I didn't make it up. I just followed the guide. I set the same RAID kernel options as shown in the guide but maybe there is some other requirement not shown in the guide but actually required? The CONFIG_RAID_ATTRS is not discussed for instance:: keeper / # cat /usr/src/linux/.config | grep RAID CONFIG_RAID_ATTRS=m # CONFIG_BLK_DEV_3W__RAID is not set # CONFIG_SCSI_AACRAID is not set # CONFIG_MEGARAID_NEWGEN is not set # CONFIG_MEGARAID_LEGACY is not set # CONFIG_MEGARAID_SAS is not set # CONFIG_SCSI_PMCRAID is not set CONFIG_MD_RAID0=y CONFIG_MD_RAID1=y # CONFIG_MD_RAID10 is not set # CONFIG_MD_RAID456 is not set keeper / # Thanks! - Mark
