Dell POWERVAULT MD3600I - Manual (Page 171)

Storage Array Performance During Virtual Disk Copy
The following factors contribute to the overall performance of the storage array:
• I/O activity
• Virtual disk RAID level
• Virtual disk configuration — Number of drives in the virtual disk groups
• Virtual disk type — Snapshot virtual disks may take more time to copy than standard virtual disks
• Snapshots created using older RAID controller firmware versions (legacy snapshots) will take longer to
complete
During a virtual disk copy, resources for the storage array are diverted from processing I/O activity to completing a
virtual disk copy. This affects the overall performance of the storage array. When you create a new virtual disk copy,
you define the copy priority to determine how much controller processing time is diverted from I/O activity to a virtual
disk copy operation.
Setting Copy Priority
You can use the Copy Manager to select the rate at which a virtual disk copy completes for a selected copy pair. You
can change the copy priority for a copy pair at any of these times:
• Before the virtual disk copy begins
• While the virtual disk copy has a status of In Progress
• When you re-create a virtual disk copy
To set copy priority:
1. In the AMW, select the Storage & Copy Services tab and select Copy Services → Virtual Disk Copy → Manage
Copies.
The Copy Manager window is displayed.
2. In the table, select one or more copy pairs.
3. Select Change → Copy Priority.
The Change Copy Priority window is displayed.
4. In the Copy Priority area, select the appropriate copy priority, depending on your system performance needs.
NOTE: There are five copy priority rates available:
– lowest
– low
– medium
– high
– highest
If the copy priority is set at the lowest rate, I/O activity is prioritized, and the virtual disk copy takes longer.
Stopping A Virtual Disk Copy
You can stop a virtual disk copy operation that has an In Progress status, a Pending status, or a Failed status. Stopping a
virtual disk copy that has a Failed status clears the Needs Attention status displayed for the storage array.
Keep these guidelines in mind when you stop a virtual disk copy:
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