StorageWorks Virtual Arrays/va7xxx-series

[Dave Pinsker]

In configuring a new va7110, the concept of "image disks" is vague. The User and Service Guide states that one of the functions of an image disk is:

"The image disks have space reserved for copies, or 'images', of the write
cache and virtualization data structures stored in the controller NVRAM."

What is not clear however, is *how much* space is reserved. Is this similar to a parity stripe where the bulk of the disk's capacity is available for storage, or are the disks fully reserved and unavailable for data?

Thank you,

_Dave_

[Julian Perez_1 · Accepted solution]

Hello,

Not all image disk is reserved for images.

The NVRAM data, which contains the critical LUN map information, can be written to disk on the VA. Two disks on the VA, called â image disksâ are used for this purpose. The NVRAM data is backed up to the image disks every 4 seconds by default.

Finally, the maps saved off to disk are based on the amount of RAM that exist in your controllers, so it's not necessary for firmware to use all complete disk.

Best regards,