Converting to raid1 from a bare partition structure: Overview: Starting system: 1 drive: /dev/sda Materials: 2 spare drives Finished system: 2 drives, all partitions RAID1, original /dev/sda as spare
- Insert spare drive as /dev/sdb
- Find out what the existing partition structure is:
root@kepler:~# fdisk -l Disk /dev/sda: 160.0 GB, 160000000000 bytes 255 heads, 63 sectors/track, 19452 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000a29dc Device Boot Start End Blocks Id System /dev/sda1 * 1 18660 149879808 83 Linux /dev/sda2 18660 19453 6367233 5 Extended /dev/sda5 18660 19453 6367232 82 Linux swap / Solaris Disk /dev/sdb: 160.0 GB, 160041885696 bytes 255 heads, 63 sectors/track, 19457 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Disk /dev/sdb doesn't contain a valid partition table root@kepler:~#
- Now create a compatible (NOT exact) structure on the target. Note that I definitely prefer a /boot partition on it's own, se we're going to fix that too -- use your favorite partitioning tool, and create a result that looks something like this:
root@kepler:~# fdisk -l Disk /dev/sda: 160.0 GB, 160000000000 bytes ((**UNMODIFIED**)) 255 heads, 63 sectors/track, 19452 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x000a29dc Device Boot Start End Blocks Id System /dev/sda1 * 1 18660 149879808 83 Linux /dev/sda2 18660 19453 6367233 5 Extended /dev/sda5 18660 19453 6367232 82 Linux swap / Solaris Disk /dev/sdb: 160.0 GB, 160041885696 bytes ((**New Partitions**) 255 heads, 63 sectors/track, 19457 cylinders Units = cylinders of 16065 * 512 = 8225280 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdb1 1 36 289138+ fd Linux raid autodetect /dev/sdb2 37 18659 149589247+ fd Linux raid autodetect /dev/sdb3 18660 19452 6369772+ 5 Extended /dev/sdb5 18660 19452 6369741 fd Linux raid autodetect root@kepler:~#
- Construct degraded raidsets for each of the new partitions
root@kepler:# mdadm --create /dev/md0 --level=1 --raid-devices=2 missing /dev/sdb1 mdadm: Note: this array has metadata at the start and may not be suitable as a boot device. If you plan to store '/boot' on this device please ensure that your boot-loader understands md/v1.x metadata, or use --metadata=0.90 Continue creating array? y mdadm: Defaulting to version 1.2 metadata mdadm: array /dev/md0 started. root@kepler:# mdadm --create /dev/md1 --level=1 --raid-devices=2 missing /dev/sdb2 mdadm: Note: this array has metadata at the start and may not be suitable as a boot device. If you plan to store '/boot' on this device please ensure that your boot-loader understands md/v1.x metadata, or use --metadata=0.90 Continue creating array? y mdadm: Defaulting to version 1.2 metadata mdadm: array /dev/md1 started. root@kepler:# mdadm --create /dev/md2 --level=1 --raid-devices=2 missing /dev/sdb5 mdadm: Note: this array has metadata at the start and may not be suitable as a boot device. If you plan to store '/boot' on this device please ensure that your boot-loader understands md/v1.x metadata, or use --metadata=0.90 Continue creating array? y mdadm: Defaulting to version 1.2 metadata mdadm: array /dev/md2 started. root@kepler:# - Verify correct creation of degraded raidsets:
root@kepler:~# cat /proc/mdstat Personalities : [raid1] md2 : active raid1 sdb5[1] 6368705 blocks super 1.2 [2/1] [_U] md1 : active raid1 sdb2[1] 149588151 blocks super 1.2 [2/1] [_U] md0 : active raid1 sdb1[1] 289126 blocks super 1.2 [2/1] [_U] unused devices: root@kepler:~# - Format file systems onto the md devices as appropriate:
root@kepler:~# mke2fs /dev/md0 mke2fs 1.41.12 (17-May-2010) Filesystem label= OS type: Linux Block size=1024 (log=0) Fragment size=1024 (log=0) Stride=0 blocks, Stripe width=0 blocks 72288 inodes, 289124 blocks 14456 blocks (5.00%) reserved for the super user First data block=1 Maximum filesystem blocks=67633152 36 block groups 8192 blocks per group, 8192 fragments per group 2008 inodes per group Superblock backups stored on blocks: 8193, 24577, 40961, 57345, 73729, 204801, 221185 Writing inode tables: done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 36 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. root@kepler:~# mke2fs -j /dev/md1 mke2fs 1.41.12 (17-May-2010) Filesystem label= OS type: Linux Block size=4096 (log=2) Fragment size=4096 (log=2) Stride=0 blocks, Stripe width=0 blocks 9355264 inodes, 37397037 blocks 1869851 blocks (5.00%) reserved for the super user First data block=0 Maximum filesystem blocks=4294967296 1142 block groups 32768 blocks per group, 32768 fragments per group 8192 inodes per group Superblock backups stored on blocks: 32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 4096000, 7962624, 11239424, 20480000, 23887872 Writing inode tables: done Creating journal (32768 blocks): done Writing superblocks and filesystem accounting information: done This filesystem will be automatically checked every 38 mounts or 180 days, whichever comes first. Use tune2fs -c or -i to override. root@kepler:~# mkswap /dev/md2 mkswap: /dev/md2: warning: don't erase bootbits sectors on whole disk. Use -f to force. Setting up swapspace version 1, size = 6368700 KiB no label, UUID=eddc5aa2-35ad-45f1-97db-41a9fb76dbab root@kepler:~# - Copy filesystem data ... in this case, we are copying a root filesystem, and we do NOT want to copy any of the operating system special directories' contents... so we will use 'cp -a' for each NON-system directory in root... e.g. :
root@kepler:/# ls / bin dev home lib lost+found mnt opt root selinux sys usr vmlinuz boot etc initrd.img lib64 media oldkepler proc sbin srv tmp var //Note we omit dev lost+found mnt sys proc tmp //Note: be careful with /media & contents as well root@kepler:/# cp -a bin home lib opt root selinux usr vmlinuz boot etc initrd.img lib64 media oldkepler sbin srv var /mnt
- Create the directories we did not copy in step 6 so they are present
when boot the operating system onto the new drives ... and remember to fix up the modes so they're right too root@kepler:/mnt# mkdir dev mnt sys proc tmp root@kepler:/mnt# cd / root@kepler:/# ls -ldah dev mnt sys proc tmp drwxr-xr-x 17 root root 3.0K Dec 14 08:54 dev drwxr-xr-x 13 root root 4.0K Dec 14 09:49 mnt dr-xr-xr-x 119 root root 0 Dec 11 14:56 proc drwxr-xr-x 13 root root 0 Dec 11 14:56 sys drwxrwxrwt 2 root root 4.0K Dec 14 09:50 tmp root@kepler:/# cd - /mnt root@kepler:/mnt# chmod 755 dev mnt sys ; chmod 777 tmp ; chmod +t tmp ; chmod 555 proc root@kepler:/mnt# ls -ldah dev mnt sys proc tmp drwxr-xr-x 2 root root 4.0K Dec 14 09:48 dev drwxr-xr-x 2 root root 4.0K Dec 14 09:48 mnt dr-xr-xr-x 2 root root 4.0K Dec 14 09:48 proc drwxr-xr-x 2 root root 4.0K Dec 14 09:48 sys drwxrwxrwt 2 root root 4.0K Dec 14 09:48 tmp root@kepler:/mnt#
- Copy/move any other partitions if you are rearranging your partition layout in this process.
In this example, I am breaking boot out to it's own partition root@kepler:/mnt# ls -ldah boot drwxr-xr-x 3 root root 4.0K Dec 14 08:52 boot root@kepler:/mnt# mv boot bootold ; mkdir -m0744 boot ; ls -ldah boot drwxr--r-- 2 root root 4.0K Dec 14 10:48 boot root@kepler:/mnt# mount /dev/md0 /mnt/boot root@kepler:/mnt# mv bootold/* boot/ root@kepler:/mnt# rmdir bootold
- Generate the appropriate /etc/mdadm/mdadm.conf file in the new root
root@kepler:/mnt# mdadm --detail --scan >>/mnt/etc/mdadm/mdadm.conf root@kepler:/mnt# cat /mnt/etc/mdadm/mdadm.conf # mdadm.conf # # Please refer to mdadm.conf(5) for information about this file. # # by default, scan all partitions (/proc/partitions) for MD superblocks. # alternatively, specify devices to scan, using wildcards if desired. DEVICE partitions # auto-create devices with Debian standard permissions CREATE owner=root group=disk mode=0660 auto=yes # automatically tag new arrays as belonging to the local system HOMEHOST # instruct the monitoring daemon where to send mail alerts MAILADDR root # definitions of existing MD arrays # This file was auto-generated on Fri, 14 Dec 2012 08:52:15 -0600 # by mkconf 3.1.4-1+8efb9d1+squeeze1 ARRAY /dev/md0 metadata=1.2 name=kepler:0 UUID=766506ff:e42e6a66:ce138bda:4a066256 ARRAY /dev/md1 metadata=1.2 name=kepler:1 UUID=688eed4a:2d64e8bc:e5e6cce4:ec26897e ARRAY /dev/md2 metadata=1.2 name=kepler:2 UUID=20b9a69a:7ac619bc:e7814e3a:2de54ae0 root@kepler:/mnt#
- Fix the /etc/fstab in the target root
Before: root@kepler:/mnt/etc# cat fstab # /etc/fstab: static file system information. # # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID= as a more robust way to name devices # that works even if disks are added and removed. See fstab(5). # # proc /proc proc defaults 0 0 # / was on /dev/sda1 during installation UUID=6b9da7ff-3f61-4d6c-b8b2-d010641e918c / ext3 errors=remount-ro 0 1 # swap was on /dev/sda5 during installation UUID=9a0cfe1c-0801-45b1-83ab-b870185be9d9 none swap sw 0 0 /dev/scd0 /media/cdrom0 udf,iso9660 user,noauto 0 0 root@kepler:/mnt/etc# After: root@kepler:/mnt/etc# cat fstab # /etc/fstab: static file system information. # # Use 'blkid' to print the universally unique identifier for a # device; this may be used with UUID= as a more robust way to name devices # that works even if disks are added and removed. See fstab(5). # # proc /proc proc defaults 0 0 # / was on /dev/sda1 during installation /dev/md1 / ext3 errors=remount-ro 0 1 /dev/md0 /boot ext2 errors=remount-ro 0 1 # swap was on /dev/sda5 during installation /dev/md2 none swap sw 0 0 /dev/scd0 /media/cdrom0 udf,iso9660 user,noauto 0 0 root@kepler:/mnt/etc#
- Edit target /boot/grub/device.map
Before: (hd0) /dev/disk/by-id/scsi-1ATA_ST3160812AS_5LSEGGJL After (hd0) /dev/sda (hd1) /dev/sdb ----note: you MAY want to keep the '/dev/disk/by-id/' naming, but you will need to do further edits of /boot/grub/device.map as you proceed with the steps below - Chroot into new target, reinstall grub, update grub.cfg / rebuild initrd
root@kepler:/mnt/boot/grub# mount --bind /dev /mnt/dev root@kepler:/mnt/boot/grub# mount --bind /sys /mnt/sys root@kepler:/mnt/boot/grub# chroot /mnt root@kepler:/# grub-install /dev/sdb root@kepler:/# update-grub Generating grub.cfg ... Found linux image: /boot/vmlinuz-2.6.32-5-amd64 Found initrd image: /boot/initrd.img-2.6.32-5-amd64 grep: /proc/mounts: No such file or directory grep: /proc/swaps: No such file or directory done root@kepler:/# exit root@kepler:/mnt/boot/grub# umount /mnt/sys root@kepler:/mnt/boot/grub# umount /mnt/dev
- Shutdown - rearrange drives, remove source drive, and attempt boot to new system (Note that for our example here, this means remove sda, then move sdb to sda, insert spare sdb)
If all goes well, you're now up & running on all degraded raid1 md sets root@kepler:~# df -ah Filesystem Size Used Avail Use% Mounted on /dev/md1 141G 29G 105G 22% / tmpfs 4.0G 0 4.0G 0% /lib/init/rw proc 0 0 0 - /proc sysfs 0 0 0 - /sys udev 4.0G 160K 4.0G 1% /dev tmpfs 4.0G 0 4.0G 0% /dev/shm devpts 0 0 0 - /dev/pts /dev/md0 274M 20M 240M 8% /boot root@kepler:~# swapon -s Filename Type Size Used Priority /dev/md2 partition 6368696 0 -1 root@kepler:~#
- Partition the new spare drive that will be our raid partner
root@kepler:~# sfdisk -d /dev/sda | sfdisk /dev/sdb Checking that no-one is using this disk right now ... OK Disk /dev/sdb: 19457 cylinders, 255 heads, 63 sectors/track sfdisk: ERROR: sector 0 does not have an msdos signature /dev/sdb: unrecognized partition table type Old situation: No partitions found New situation: Units = sectors of 512 bytes, counting from 0 Device Boot Start End #sectors Id System /dev/sdb1 63 578339 578277 fd Linux raid autodetect /dev/sdb2 578340 299756834 299178495 fd Linux raid autodetect /dev/sdb3 299756835 312496379 12739545 5 Extended /dev/sdb4 0 - 0 0 Empty /dev/sdb5 299756898 312496379 12739482 fd Linux raid autodetect Warning: no primary partition is marked bootable (active) This does not matter for LILO, but the DOS MBR will not boot this disk. Successfully wrote the new partition table Re-reading the partition table ... If you created or changed a DOS partition, /dev/foo7, say, then use dd(1) to zero the first 512 bytes: dd if=/dev/zero of=/dev/foo7 bs=512 count=1 (See fdisk(8).) root@kepler:~#
- Add the target partitions into the degraded raidsets
root@kepler:~# mdadm --manage /dev/md0 --add /dev/sdb1 mdadm: added /dev/sdb1 root@kepler:~# mdadm --manage /dev/md1 --add /dev/sdb2 mdadm: added /dev/sdb2 root@kepler:~# mdadm --manage /dev/md2 --add /dev/sdb5 mdadm: added /dev/sdb5 root@kepler:~# cat /proc/mdstat Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] md0 : active raid1 sdb1[2] sda1[1] 289126 blocks super 1.2 [2/2] [UU] md1 : active raid1 sdb2[2] sda2[1] 149588151 blocks super 1.2 [2/1] [_U] [>....................] recovery = 0.3% (471552/149588151) finish=52.6min speed=47155K/sec md2 : active raid1 sdb5[2] sda5[1] 6368705 blocks super 1.2 [2/1] [_U] resync=DELAYED unused devices: root@kepler:~# - Rewrite grub onto new spare drive
root@kepler:~# grub-install /dev/sdb Installation finished. No error reported.
