4.0

Table Of Contents
Managing Storage Groups
94
Storage Group and Chunk Sizes
Storage Elements are combined to create Storage Groups in the ISIS file system. When you bind
a Storage Element you must select either 512 KB (default) or 256 KB chunk sizes. Earlier Avid
ISIS releases used 256 KB chunk sizes. These bound Storage Elements must all be of the same
chunk size when you configure your Storage Group.
n
Avid ISIS switch hardware shipped with v1.x (ISS1000 and IXS1000) does not support 512 KB
chunk sizes. If you have Avid ISIS v2.x software running on v1.x switches, you must select the
256 KB chunk size when adding Storage Elements to the file system to create Storage Groups.
You cannot change the chunk size of a Storage Group once the Storage Group has been created.
To change the chunk size of an existing Storage Group, you must delete the Storage Group and
create a new Storage Group with the desired chunk size. The chunk size selection is only
available when adding the Storage Elements.
Storage Blades and Chunk Sizes
There are two drives in all Avid ISIS 7000 ISBs. ISBs are identified by the total amount of
storage in the ISB; for example, an ISB with the two 1 terabyte (TB) drives are referred to as
i2000s. All ISBs (i500, i1000, i2000, and i4000) support the 512 KB chunk size, but only the
i500 and i1000 support the 256k chunk size. The i2000 and i4000 ISBs require 512 KB chunk
size. In addition you must have v2.x switch hardware (ISS2000 and IXS2000) to use the 512 KB
chunk size.
RAID 6 Workspace, Single ISB Failure
When there is a single ISB failure in an ISIS Workspace configured with RAID 6 protection, the
Workspace continues to function normally at a lower bandwidth. For mirrored Workspace, see
“Mirrored Workspace, Single ISB Failure” on page 95.
After confirming the failure of an ISB, it is highly recommended that you initiate the remove
redistribution process of the failed ISB immediately. There are two benefits to doing this:
First, immediately upon initiation of the remove redistribution, all new writes to the
Workspace have the full benefit of RAID-6 protection (dual-parity protection).
Second, upon completion of the remove redistribution process, existing data in the
Workspace is once again fully protected. Prior to completion, if another ISB were to fail, the
Workspace would be in an unprotected state (though no data would be lost).