BC4000 Series RAID Controllers
User Manual
02/13/06
B ro ad c om C o r p or at i on
Page 134
Transforming Arrays: bcadm --transform
Document
BC4000-UM100-R
T
RANSFORMING
A
RRAYS
: bcadm --transform
The
bcadm --transform
or
bcadm -T
command allows you to transform an array from one RAID level to
almost any other RAID level and expand the array dynamically, even under I/O load. If you have the level 52
license, you can use the Online Capacity Expansion (OCE)
and Online RAID Level Migration (ORLM) features
to increase the size and organization of an array. These features can also be used as an integral part of the
system backup and recover strategy through the use of the RAID1, RAID10, RAID1n, and RAID10n array
types.
S
YNTAX
The following <
raid_type
> attributes are available. The long and short formats for each attribute are given.
Notes:
•
You cannot transform to a smaller-sized array. New arrays must be either the same capacity or
larger.
•
If the system reboots in the middle of a transform, the transform continues where it left off.
•
When using the task control option, a transform can only be paused/resumed but not removed.
•
If a drive fails while the transform is in progress, no data is lost as long as the source and
destination array types are redundant. If a spare has been assigned to the destination array, a
failover task starts as soon as the transform completes provided the spare is available after the
transform.
•
If there are multiple arrays on the controller, it may not be possible to transform some of the arrays
to a larger size. If you think that at some time you will need to expand the size of an array, it is
best to configure the available space as a single array.
•
The array size of the transformed array is limited to 2.199 TB on some versions of Windows and
Linux. Please refer to your OS documentation for details on maximum array sizes.
Long form:
bcadm --transform <raid_type> --array <num> --disk <list>
[--size <size_mb>] [--same-size]
[--sub-member <num>] [--d-spare]
[--max-size] [--priority <1...10>]
Short form:
bcadm -T <raid_type> -a <num> -d <list>
[-s <size_mb>] [-ss] [-sub <num>]
[-ds] [-ms] [-p <1...10>]
--linear
-l
Single disk or concatenation of disks (Volume)
--volume
-v
Single disk or concatenation of disks (Volume)
--raid0
-r0
Stripe of two or more disks
--raid1
-r1
Mirror of two disks
--raid1n
-r1n
Mirror of three or more disks
--raid10
-r10
Stripe set of mirror sets
--raid10n
-r10n
Stripe set of n-way mirror sets
--raid5
-r5
Stripe set with parity, three to sixteen disks
--raid50
-r50
Stripe set of RAID5 sets