Administrator Guide

Disable Data Reduction for a Volume
Disabling Data Reduction on a volume permanently uncompresses the reduced data starting the next data progression cycle.
Steps
1. If you are connected to a Data Collector, select a Storage Center from the drop-down list in the left navigation pane of
Unisphere Central.
2. From the
STORAGE menu, click Volumes.
The Volumes view is displayed.
3. In the Volumes view, select the volume you want to modify.
4. Click (Edit).
The Edit Volume dialog box opens.
5. Expand the Data Reduction option.
6. From the Data Reduction Profile drop-down menu, select None.
7. Click OK.
Managing Snapshot Profiles
A Snapshot Profile is a collection of rules describing when to take periodic snapshots for one or more volumes and the time at
which snapshots are deleted (expired).
A snapshot is a point-in-time copy (PITC) of one or more volumes. Storage Center snapshots differ from traditional snapshots/
PITCs because blocks of data or pages are frozen and not copied. No user data is moved, making the process efficient in both
time taken to complete the snapshot, and space used by snapshots.
NOTE:
If two or more snapshots are scheduled to be created at the same time for a given volume, the Storage Center
creates only one snapshot. The snapshot that has the longest expiration time is created, and the other scheduled snapshots
are ignored.
Default Snapshot Profiles
By default, Storage Center provides two standard snapshot profiles that cannot be deleted.
● Daily – Creates a snapshot every day at 12:01 AM, and expires the snapshot in one week.
● Sample – Applies three schedule rules:
○ Creates a snapshot every 12 hours between 12:05 AM and 6 PM, expiring in five days.
○ Creates a snapshot on the first day of every month at 11:30 PM, expiring in 26 weeks.
○ Creates a snapshot every Saturday at 11:30 PM, expiring in 5 weeks.
Consistent and Non-Consistent Snapshot Profiles
When a snapshot is taken for a volume, I/O is halted to allow the operation to take place. A consistent snapshot profile halts I/O
to all associated volumes until a snapshot is taken for each volume, ensuring that the snapshots contain data for the same time
period. A non-consistent snapshot profile creates snapshots for associated volumes without guaranteeing that the snapshots
will finish at the same time, which is less resource intensive.
Consistent Snapshot Profile
Non-Consistent Snapshot Profile
Halts I/O across all volumes as a group Halts I/O for each volume independently of other volumes.
Resource intensive Less resource intensive — depends on the amount of data
written since the previous snapshot
Number of volumes limited based on storage controller.
● SC8000, SC9000, SC7020, and SC7020F: 100
● SC5020 and SC5020F: 50
No limit to the number of volumes to which the snapshot
profile is attached
88 Storage Center Administration