IBM System Storage DS3000, Programming Manual

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Notes
Host I/O errors might result in subsystems with more than 32 logical drives. This operation also might
result in internal controller reboots because the timeout period ends before the subsystem definition is
set. If you experience this issue, quiesce the host I/O operations, and try the command again.
When you use this command, you can specify one or more of the parameters.
Important: Specifying the addDrives parameter or the raidLevel parameter starts a long-running
operation that you cannot stop.
The
addDrives
parameter supports both high-capacity and low-capacity drive expansion enclosures. A
high-capacity drive expansion enclosure has drawers that hold the drives. The drawers slide out of the
drive expansion enclosure to provide access to the drives. A low-capacity drive expansion enclosure does
not have drawers. For a high-capacity drive expansion enclosure, you must specify the identifier (ID) of
the drive expansion enclosure, the ID of the drawer, and the ID of the slot in which a drive resides. For a
low-capacity drive expansion enclosure, you need to specify the ID of the drive expansion enclosure and
the ID of the slot in which a drive resides. For a low-capacity drive expansion enclosure, an alternative
method for identifying a location for a drive is to specify the ID of the drive expansion enclosure, set the
ID of the drawer to 0, and specify the ID of the slot in which a drive resides.
Troubleshooting
An attempt to expand large subsystems by adding drives, also called Dynamic Capacity Expansion
(DCE), might fail with the following message:
Return code: Error 26 - The modification operation cannot complete because
of the number of drives in the subsystem and the segment size of the associated
logical drives. Reduce the segment size of all logical drives in the subsystem
to 128 KB or below using the Change Segment Size option. Then, retry the
operation.
Systems running 7.35.xx.xx firmware might fail with the following message instead of the message given
earlier:
Return code: Error 462 - A SYMbol procedure could not be carried out because
the firmware could not allocate sufficient cache memory. Operation when
error occurred: PROC_startVolum
In addition to the above messages, a Major Event Log (MEL) event that indicates unavailability of
sufficient cache to complete the DCE operation might occur.
Any controller running 7.xx firmware can encounter this problem. DCE requires enough memory to
buffer the data read from the original logical drive and the data to be written to the expanded logical
drive. Some combination of number of drives in the expansion operation, stripe size, and whether
mirroring is enabled may result in not enough memory being available to complete the DCE operation.
If such a situation occurs, possible workarounds are as follows:
v Create the desired size subsystem using other unassigned drives.
v
Delete the current subsystem and then re-create the subsystem with the desired number of drives.
v Reduce the segment size being used and then retry the operation.
v
If possible, add additional memory to the controller and then retry the operation.
Chapter 3. Script Commands
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