Solaris Mirrored root disk on Solaris

Mirrored root disk on Solaris

http://www.brandonhutchinson.com/Mirroring_disks_with_DiskSuite.html


0. Partition the first disk

# format c0t0d0

Use the partition tool (=> "p , p "!) to setup the slices. We assume the following slice setup afterwards:

# Tag Flag Cylinders Size Blocks
- ---------- ---- ------------- -------- --------------------
0 root wm 0 - 812 400.15MB (813/0/0) 819504
1 swap wu 813 - 1333 256.43MB (521/0/0) 525168
2 backup wm 0 - 17659 8.49GB (17660/0/0) 17801280
3 unassigned wm 1334 - 1354 10.34MB (21/0/0) 21168
4 var wm 1355 - 8522 3.45GB (7168/0/0) 7225344
5 usr wm 8523 - 14764 3.00GB (6242/0/0) 6291936
6 unassigned wm 14765 - 16845 1.00GB (2081/0/0) 2097648
7 home wm 16846 - 17659 400.15MB (813/0/0) 819504

1. Copy the partition table of the first disk to its future mirror disk

# prtvtoc /dev/rdsk/c0t0d0s2 fmthard -s - /dev/rdsk/c0t1d0s2

2. Create at least two state database replicas on each disk

# metadb -a -f -c 2 c0t0d0s3 c0t1d0s3

Check the state of all replicas with metadb:

# metadb

Notes:

A state database replica contains configuration and state information about the meta devices. Make sure that always at least 50% of the replicas are active!


3. Create the root slice mirror and its first submirror

# metainit -f d10 1 1 c0t0d0s0
# metainit -f d20 1 1 c0t1d0s0
# metainit d30 -m d10

Run metaroot to prepare /etc/vfstab and /etc/system (do this only for the root slice!):

# metaroot d30

4. Create the swap slice mirror and its first submirror

# metainit -f d11 1 1 c0t0d0s1
# metainit -f d21 1 1 c0t1d0s1
# metainit d31 -m d11

5. Create the var slice mirror and its first submirror

# metainit -f d14 1 1 c0t0d0s4
# metainit -f d24 1 1 c0t1d0s4
# metainit d34 -m d14

6. Create the usr slice mirror and its first submirror

# metainit -f d15 1 1 c0t0d0s5
# metainit -f d25 1 1 c0t1d0s5
# metainit d35 -m d15

7. Create the unassigned slice mirror and its first submirror

# metainit -f d16 1 1 c0t0d0s6
# metainit -f d26 1 1 c0t1d0s6
# metainit d36 -m d16

8. Create the home slice mirror and its first submirror

# metainit -f d17 1 1 c0t0d0s7
# metainit -f d27 1 1 c0t1d0s7
# metainit d37 -m d17

9. Edit /etc/vfstab to mount all mirrors after boot, including mirrored swap

/etc/vfstab before changes:

fd - /dev/fd fd - no -
/proc - /proc proc - no -
/dev/dsk/c0t0d0s1 - - swap - no -
/dev/md/dsk/d30 /dev/md/rdsk/d30 / ufs 1 no logging
/dev/dsk/c0t0d0s5 /dev/rdsk/c0t0d0s5 /usr ufs 1 no ro,logging
/dev/dsk/c0t0d0s4 /dev/rdsk/c0t0d0s4 /var ufs 1 no nosuid,logging
/dev/dsk/c0t0d0s7 /dev/rdsk/c0t0d0s7 /home ufs 2 yes nosuid,logging
/dev/dsk/c0t0d0s6 /dev/rdsk/c0t0d0s6 /opt ufs 2 yes nosuid,logging
swap - /tmp tmpfs - yes -

/etc/vfstab after changes:

fd - /dev/fd fd - no -
/proc - /proc proc - no -
/dev/md/dsk/d31 - - swap - no -
/dev/md/dsk/d30 /dev/md/rdsk/d30 / ufs 1 no logging
/dev/md/dsk/d35 /dev/md/rdsk/d35 /usr ufs 1 no ro,logging
/dev/md/dsk/d34 /dev/md/rdsk/d34 /var ufs 1 no nosuid,logging
/dev/md/dsk/d37 /dev/md/rdsk/d37 /home ufs 2 yes nosuid,logging
/dev/md/dsk/d36 /dev/md/rdsk/d36 /opt ufs 2 yes nosuid,logging
swap - /tmp tmpfs - yes -

Notes:

The entry for the root device (/) has already been altered by the metaroot command we executed before.


10. Reboot the system

# lockfs -fa && init 6

11. Attach the second submirrors to all mirrors

# metattach d30 d20
# metattach d31 d21
# metattach d34 d24
# metattach d35 d25
# metattach d36 d26
# metattach d37 d27

Notes:

This will finally cause the data from the boot disk to be synchronized with the mirror drive.

You can use metastat to track the mirroring progress.


12. Change the crash dump device to the swap metadevice

# dumpadm -d `swap -l tail -1 awk '{print $1}'

13. Make the mirror disk bootable

# installboot /usr/platform/`uname -i`/lib/fs/ufs/bootblk /dev/rdsk/c0t1d0s0

Notes:

This will install a boot block to the second disk.


14. Determine the physical device path of the mirror disk

# ls -l /dev/dsk/c0t1d0s0
... /dev/dsk/c0t1d0s0 -> ../../devices/pci@1f,4000/scsi@3/sd@1,0:a

15. Create a device alias for the mirror disk

# eeprom "nvramrc=devalias mirror /pci@1f,4000/scsi@3/disk@1,0"
# eeprom "use-nvramrc?=true"

Add the mirror device alias to the Open Boot parameter boot-device to prepare the case of a problem with the primary boot device.

# eeprom "boot-device=disk mirror cdrom net"

You can also configure the device alias and boot-device list from the Open Boot Prompt (OBP a.k.a. ok prompt):

ok nvalias mirror /pci@1f,4000/scsi@3/disk@1,0
ok use-nvramrc?=true
ok boot-device=disk mirror cdrom net

Notes:

From the OBP, you can use boot mirror to boot from the mirror disk.

On my test system, I had to replace sd@1,0:a with disk@1,0. Use devalias on the OBP prompt to determine the correct device path.