Pls. help with fssnap - Solaris

samnyc · August 20, 2013, 3:40pm

Hi,

I have used Solaris but new to ZFS. I need to backup the root volume using fssnap.

 zpool list
NAME    SIZE  ALLOC   FREE    CAP  HEALTH  ALTROOT
pool5   808G   552G   256G    68%  ONLINE  -
rpool   136G  20.9G   115G    15%  ONLINE  -

 
 zfs list
NAME                     USED  AVAIL  REFER  MOUNTPOINT
pool5                    555G   240G    21K  none
pool5/sybase            1.85G  3.15G  1.85G  /usr/sybase
pool5/sybdata            550G   240G   550G  /sybdata
rpool                   42.5G  91.4G    97K  /rpool
rpool/ROOT              10.0G  91.4G    21K  legacy
rpool/ROOT/solaris10u9  4.93G  5.07G  4.93G  /
rpool/dump              16.0G  91.4G  16.0G  -
rpool/data               30.5K  91.4G  30.5K  /data
rpool/swap              16.5G   108G    16K  -

I want to save the data on to pool5(/Sybase) since I have close to 240 Gig free of space on that from above. Please advise how to do this?

 
fssnap -o backing-store=/ /data/ /sybdata/Aug20_full_backup     Is this correct???

jlliagre · August 20, 2013, 6:45pm

No. fssnap is to be used with UFS only. ZFS doesn't need it as it already has the snapshot facility built in.

It is unclear what you want to backup. You don't backup volumes but file systems so you can create a snapshot of the dataset (file system) you want to backup, say /data, like this:

zfs snapshot rpool/data@now

and then you can backup the following file system using the tool you want:

/data/.zfs/snapshot/now

With ZFS that could be zfs send ... | zfs receive ... but you can also use rsync, tar, cpio, whatever.
Finally, when you are done you can delete the snapshot to make sure no disk space is wasted with

zfs destroy rpool/data@now

achenle · August 20, 2013, 8:53pm

You can take a snapshot of an entire pool and all file systems included:

zfs snapshot -r rpool@now

From "man zfs" (Solaris 11, though):

Snapshots
A snapshot is a read-only copy of a file system or volume.
Snapshots can be created extremely quickly, and initially
consume no additional space within the pool. As data within
the active dataset changes, the snapshot consumes more data
than would otherwise be shared with the active dataset.

Snapshots can have arbitrary names. Snapshots of volumes can
be cloned or rolled back, but cannot be accessed indepen-
dently.

File system snapshots can be accessed under the
".zfs/snapshot" directory in the root of the file system.
Snapshots are automatically mounted on demand and may be
unmounted at regular intervals. The visibility of the ".zfs"
directory can be controlled by the "snapdir" property.

...

zfs snapshot [-r] [-o property=value] ...
filesystem@snapname|volume@snapname

Creates a snapshot with the given name. See the
"Snapshots" section for details.

-r

Recursively create snapshots of all descendent
datasets. Snapshots are taken atomically, so that
all recursive snapshots correspond to the same
moment in time.

-o property=value

Sets the specified property; see "zfs create" for
details.

samnyc · August 21, 2013, 9:59am

Thank you so much Jlliagre and achenle for the info. I will try the zfs snapshot and get back.