Administrator Guide

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 Proles
By default, Storage Center provides two standard snapshot proles 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 ve days.
– Creates a snapshot on the rst 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 Proles
When a snapshot is taken for a volume, I/O is halted to allow the operation to take place. A consistent snapshot prole 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 prole creates
snapshots for associated volumes without guaranteeing that the snapshots will nish at the same time,
which is less resource intensive.
Consistent Snapshot Prole Non-Consistent Snapshot Prole
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
• SC4020: 40
• SCv2000 and SCv3000 series: 25
No limit to the number of volumes to which the snapshot prole is
attached
Snapshots are taken of all volumes simultaneously Choose between standard (one volume at a time) or parallel (all
volumes simultaneously)
Can set an alert if snapshots cannot be completed within a dened
time. Snapshots not completed before alert is generated are not
taken. (This suspension can lead to incomplete groups of snapshots
across volumes.)
All snapshots are taken
Can delete incomplete group of snapshots All snapshots are taken
Can be converted to Non-Consistent snapshot prole Can be converted to Consistent snapshot prole
Creating and Applying Snapshot Proles
To create and expire snapshots automatically, create a snapshot prole and apply it to one or more volumes or servers.
NOTE
: For user interface reference information, click Help.
74 Storage Center Administration