UFS – Unix File System
ZFS – Zettabyte File System
UFS is a file system used exclusively with Unix, and all Unix-like operation systems.
ZFS is an Open Source software that is licensed under the Common Development and Distribution License (or CDDL).
Inodes are created at the time of creating the file system and are used to refer the files/directories.
Vnodes are created at the time when files/directories are created and are used to refer the files/directories.
Mirroring occurs on the block level.
Mirroring occurs on the data level.
Can have only one snapshot for a same file system.
Can have more than one snapshot for a same file system.
ZFS have inbuilt Volume Manager.
Saturday, August 27, 2011
Friday, August 19, 2011
What to do?
1. Ensure that the alternate disk has equal geometry & size.
2. Take backup of /etc/system and /etc/vfstab file.
3. Copy VTOC from root (booting) disk to the alternate disk.
4. Ensure that the state database is created.
5. Convert the root slice as a logical component forcefully.
6. Create another metadevice for duplicating root slice.
7. Convert the swap slice as a logical component forcefully.
8. Create another metadevce for duplicating the swap slice.
9. Associate first sub-mirror (for root) to mirror root.
10. Associate first sub-mirror (for swap) to mirror swap.
11. Update the system & vfstab file by running 'metaroot' command.
12. Reboot the system.
13. Associate the second sub-mirror to mirror root.
14. Associate the second sub-mirror to mirror swap.
15. Install boot block (in case of SPARC machine) or grub (X86 machine) in the alternate root slice
16. See the physical path for the alternate disk
17 Set alias name in the OK prompt.
18. Set boot sequence in OK prompt.
How to do?
1. # format
Create the slices manually.
2. # cp /etc/system /etc/system.orig
# cp /etc/vfstab /etc/vfstab.orig
3. # prtvtoc /dev/rdsk/c0t0d0s2 | fmthard -s - /dev/rdsk/c0t12d0s2
fmthard -> populate label on the new hard disk drive
4. # metadb -afc3 c0t8d0s7 c0t10d0s7 c0t12d0s7
(if the replicas are existing, this step can be avoided)
5. # metainit -f d5 1 1 c0t8d0s0
Converting forcefully the root slice as a metadevice
6. # metainit d10 1 1 c0t12d0s0
Creating another metadevice for root
7. # metainit -f d25 1 1 c0t8d0s1
Converting forceful the swap slice as a metadevice
8. # metainit d30 1 1 c0t12d0s1
Creating another metadevice for swap
9. # metainit d15 -m d5
Associating d5 with d15
Here d15 = main mirror for root
10. # metainit d35 -m d25
Associate d35 with d25
Here d35 = main mirror for swap
11. # metaroot d15
a. 'metaroot' edits the file /etc/system and /etc/vfstab so that the system may be booted with the root filesystem on a meta device.
b. 'metaroot' may also be used to edit the files so that the system may be booted with root file system on a conventional disk device.
c. Observe the changes to the files /etc/vfstab and /etc/system.
12. # init 6
Make sure the sync is completed before rebooting the system
by executing the command # metastat | grep %. It consume some time.
13. # metattach d15 d10
For root adding sub-mirror
14. # metattach d35 d30
For swap adding sub-mirror
15. # cd /usr/platform/`uname -m`/lib/fs/ufs
# installboot bootblk /dev/rdsk/c0t12d0s0
Installing the boot block to the SPARC machine
# installgrub -fm /boot/grub/stage1 /boot/grub/stage2 /dev/rdsk/c1d0s0
Installing the grub in the X 86 machines.
16. # ls -l /dev/dsk/c0t12d0s0
Will display the physical path of the logical device.
Pls make a note of the physical path.
17. OK nvalias
18. OK setenv boot-device
BREAKING THE MIRROR:
# metadetach d120 d100
# metaroot c0t0d0s0
c0t0d0s0 = raw disk of source disk which is running with OS.
Will revert the /etc/system & /etc/vfstab to the default status.
# init 6
# metaclear d100
# metaclear -r d120