Snapshot

Snapshot  

• Snapshot technology enables you to create point-in-time copies of file systems.
• You can use Snapshot technology while applications are running and to create Snapshot copies in less than a second.
• Storing a Snapshot copy on a NetApp system has no performance impact while creating and deleting Snapshot copies.
• Make up to 255 Snapshot copies per volume.
• When we create a weekly, nightly, or hourly snapshot, the lowest value is newly created snapshot and highest value is older snapshot.

Snapshot space consumption

• Snapshot will not take space while creating new snapshot until the file deleted. 
• We have 3 files in the volume and each file having 10mb of size. At this time when we creating new snap1 and the snapshot size is little 4kb Size only. Because the snapshot pointing only the inodes, after you delete one file in the volume now the snap1 size should be the deleted file size. 

Snapshot Technologies

SnapDrive
SnapManager
SnapRestore
SnapMirror
SnapVault
FlexClone 

 

Commands related to Netapp Snapshot Management

All of the snap commands take the options -A and -V. to specify –A for Aggregate and –V for Volume

Volume creation commands 

To view snapshot of volume

bang> snap list vol1
Volume vol1
working...
%/used %/total date name
---------- ---------- ------------ --------
37% (37%) 0% ( 0%) Dec 02 16:00 hourly.0
51% (33%) 0% ( 0%) Dec 02 12:00 hourly.1
62% (36%) 0% ( 0%) Dec 02 08:00 hourly.2
63% (15%) 0% ( 0%) Dec 02 00:01 nightly.0
70% (46%) 0% ( 0%) Dec 01 20:00 hourly.3
74% (46%) 0% ( 0%) Dec 01 16:00 hourly.4
78% (56%) 0% ( 0%) Dec 01 00:01 nightly.1

To take snapshots manually

Snapshot Rename

Snapshot delete

Snapshot Disable

Command : 

vol options vol_name nosnap on

                (or) 

snap sched vol_name 000

the both command will not take snapshot for that specific volume.

Snapshot scheduling

1. Retain up to 255 Snapshot copies per volume for any schedule.
2. Scheduling for automatic snapshot to keep 2 weekly, 2 daily, 4 hourly(take at 2,6,10,12) online.

Snapshot Space Reservation

I. Default snapshot space reserve is 20% of the volume size

II. Changing the snapshot reserve to 5% of the volume size

Now the snapshot avail space changed 40mb to 10mb

Snap restore

• Snap restore is license product in Netapp.
• Restore the volume (or) file state as it is when snapshot is taken.
• Recover entire volumes or individual files in seconds.

File restore using snapshot

I. We can restore the specific file or Lun in the volume

 Snap autodelete

• Snap autodelete is used to automatically delete the old snapshots in the flexible volume. 
• When the volume is nearly full, the old Snapshot copies will delete automatically. 
• Snap autodelete future works together with try_first controls.

Syntax:

Bang1> snap autodelete vol_name on | off 

Bang1> vol options vol-name try_first [volume_grow|snap_delete]

To enable snap autodelete

Bang1> snap autodelete vol1 on

Bang1> vol options vol1 try_first "snap_delete"

Snap delta 

It estimate rate of change of data between two different snapshots copies in the volume

Syntax: 

Snap delta from hourly.0 to hourly.1 

Bang1>  snap delta vol_name hourly.0 hourly.1 

Snap delta from nightly.0 to hourly.1

Bang1>  snap delta vol_name nightly.0 hourly.1

Disable Snapshot folder to client

We can disable the snapshot folder to client access using snap vol options

Bang1> options cifs.show_snapshot off | on









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