ZFS

UNIX Solaris
1

what are all the advantages of ZFS comparing to UFS SVM

what is the use of creating file system in a file system in ZFS

2

I can give you two reasons I switched to ZFS over a year ago:

  1. Reliability: ZFS file systems are more reliable in a system crash than UFS. I had a system crash due to a power failure recently. When I powered up the system, it started immediately without fsck.
  2. Ease of configuration/maintenance: With ZFS, creating a mirrored boot drive is as easy as: zfs create mirror c0t0d0 c1t0d0. With UFS SVM, you have to name your metadevices and then create the mirror. With ZFS filesystems, you only need to remember two commands: zpool, zfs

HTH

1 Like
3

if we create file system with in a file system like zfs create pool/test1/test2 and if we look at df -h it will show all the three that is pool test1 and test2 with same memory size. whats the use of that and what is the concept behind that.

thanks in advance
dinu

4

Oracle Solaris ZFS Administration Guide

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5

once we make zpool from newly added disk can we reuse it for UFS?

thanks in advance
dinu

6

Sure. But you must remove the disk from the zpool first.

HTH

7

yeah i did but once i tried to do partition instead of starting cylinder it showed as sector
why this is happening

8

Use format to modify the cylinders on the disk. Then user newfs to created your UFS filesystems.

9

where the snapshots we taken in zfs will be saved and how we can access that

thanks in advance
dinu

10

snapshots in zfs are saved as a dataset under the same zpool that the actual filesystems is on. It is just a point in time snap of the filesystem and only saves the actual changes that happened from the time the snap was taken. If you want to take a backup of you filesystem and mount it us the zfs send and zfs recieve commands. This will create a backup file of your snapshot and then you can import it back into a different zfs filesystem using the zfs recieve command. So something like below will create a filesystem, take a snap of it, then reimport it to a different filesystem.

zpool create testpool raidz c1t0d0s3 c1t1d0s3 c1t2d0s3 c1t3d0s3 
zfs create testpool/test
zfs set mountpoint=/test testpool/test
add data to /test here.......
zfs snapshot testpool/test@testsnap
zfs send testpool/test@testsnap > /tmp/test.snap
zfs receive testpool/newtest < /tmp/test.snap
zfs set mountpoint=/test1 testpool/newtest
11

You generally can't remove a disk from a pool, especially if you have no redundancy in place.

12

Is possible to create a raidz root pool and then place the os
in this pool?
With Linux i use raid5+lvm on root,with Solaris is possible
something like this?
Thanks

13

No, The root pool must be on either a single device pool or a mirrored one. The latter is obviously recommended. Raidz is unsupported. ZFS Troubleshooting Guide - Siwiki

14

Ok,thanks

15

And with UFS and metadb?
Is possible to put / on a raid0 or raid1 md?
Thanks

16

on SVM, you can only use RAID 1 for /.