Promise Technology VTrack M-Class M200i - Manual (Page 264)

VTrak M-Class Product Manual
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Ranges of Disk Array Expansion
There are limitations to how large you can expand a disk array, depending on the
size of your current disk array.
The current iSCSI, SCSI, and Fibre Channel HBA cards and PC Operating
Systems support a 10-byte LBA format. This means that a disk array can have up
to 4 billion address blocks or sectors.
Multiply the number of blocks by the sector size to find the capacity of a disk
array:
4,000,000,000 blocks x 512 bytes per sector = 2,048,000,000,000 bytes
of data for a 2TB drive.
Note that you cannot change the size of the sectors nor can you increase the
number of address blocks above 4 billion.
As a result, there are range limits imposed upon disk array expansion as shown
in the table above. For example:
• You can expand a 2.5 TB disk array up to 4 TB
• You can only expand a 1.9 TB disk array up to 2 TB
See the chart below.
You can direct WebPAM to expand a logical drive beyond the maximum
expansion size. When the expansion is finished, WebPAM will show the logical
drive in the desired size. However, your operating system might show the logical
drive at the maximum expansion size (listed in the table above) and the rest of
the capacity as unformatted disk space.
At this point, you can:
• Format the disk space, which results in a second logical drive
• Create a new logical drive. See below
Create a New Logical Drive
To create a new logical drive:
1. Backup the data from the current logical drive.
Current LD Size
Maximum LD
Expansion Size
Sector Size
8 to 16 TB 16 TB 4096 bytes
4 to 8 TB 8 TB 2048 bytes
2 to 4 TB 4 TB 1024 bytes
0 to 2 TB 2 TB 512 bytes