SANRAD V-Switch manual Volume create snapshot, Vol Src, 146

volume create snapshot

You need four parameters to create a snapshot volume:

SWITCH PARAMETER DEFINITION STATUS EXAMPLE

-vol

-src

-ch

-lt

VOLUME	SNAPSHOT NAME	MANDATORY
SOURCE	SOURCE OF	MANDATORY
	SNAPSHOT
CHILD	SNAPSHOT CHILD	MANDATORY
LOAD THRESHOLD	PERCENTAGE FULL	OPTIONAL
	AT DESTINATION	DEFAULT: 80%
	TO TRIGGER AN
	ALARM

Example:

Figure 77 shows a source volume with its first snapshot when the snapshot is first created. Initially, a snapshot is empty because there has not yet been a change in its source volume. Only when a write operation is performed on the source volume will the snapshot begin to fill up. The pointer table for the snapshot would point to the source volume for all sectors.

volume create snapshot –vol Snapshot1 –src QATesting – dst Snapshot1 -lt 80

QA Testing

S	A	N	S
N	A	S	H
A	M	M	O
P	U	N	T

Snapshot1

10254

Figure 77. 1st Snapshot

Figure 78, page 147 shows the same source and snapshot volume after a write operation to sector 1. The original data, S, from sector 1 is first copied to the snapshot and then the new data, B, is written to the source volume.

146 SANRAD V-Switch User Manual