Promise Technology 2-Year Extended Warranty for VessR2000 RAID Head - Manual (Page 619)

592
Vess R2000 Series Product Manual Promise Technologies
• GB Truncate – (Default) Reduces the useful capacity to the nearest 1,000,000,000 byte boundary.
• 10GB Truncate – Reduces the useful capacity to the nearest 10,000,000,000 byte boundary.
• Group Rounding – Uses an algorithm to determine how much to truncate. Results in the maximum amount
of usable drive capacity.
• Table Rounding – Applies a predefined table to determine how much to truncate.
Capacity coercion also affects a replacement drive used in a disk array. Normally, when an physical drive fails,
the replacement drive must be the same capacity or larger. However, the capacity coercion feature permits the
installation of a replacement drive that is slightly smaller (within 1 gigabyte) than the remaining working drive.
For example, the remaining working drives can be 80.5 GB and the replacement drive can be 80.3, since all are
rounded down to 80 GB. This permits the smaller drive to be used.
Without capacity coercion, the controller does not permit the use of a replacement physical drive that is slightly
smaller than the remaining working drives.