Table 2 BC operational requirements for the array
Parameter
Requirement
Pair objects Logical device
s (LDEVs): OPEN-x (such as OPEN-3, OPEN-9, OPEN-E, and
OPEN-V), inclu
ding CVS and LUSE volumes. Devices must be installed and
configured. The P-VOL and S-VOL must be the same type (for example, OPEN-3
to OPEN-3 is allowed, OPEN-3 to OPEN-9 is not allowed).
AcustomsizeP-VOLmustbepairedwithS-VOLsofthesametypeandcapacity.
ALUSEP-VOLmustbepairedwithS-VOLsofthesamesizeandstructure. For
example, if a LUSE P-VOL is connected to volumes of 1GB, 2GB, and 3GB in
this order, you must specify the LUSE volume that has exactly the same size and
connection order as the S-VOL.
BC does not support multiplatform devices (for example, 3390-3A, -3B, -3C).
For information about using Snapshot XP pair volumes as Business Copy XP
volumes, pl
ease refer to Snapshot XP User’s Guide.
Snapshot XP
pairs, virtual volumes, and pool volumes cannot be specified as
P-VOLs or S-
VOLs.
Journal vo
lumes for HP StorageWorks Continuous Access XP Journal cannot be
specified as P-VOLs or S-VOLs.
Volumes that form a Flex Copy XP pair cannot be specified as P-VOLs. A Flex
Copy XP P-VOL can be specified as a Business Copy XP S-VOL under certain
conditions. Refer to the HP StorageWorks Flex Copy XP user guide for more
informat
ion.
BC operat
ions can be performed with External Storage XP operations to create
pairs th
atusetheexternalvolumesasBCS-VOLs(ormirroringvolumes)underthe
same conditions applied to the volumes in the local disk array. Refer to the HP
StorageWorks External Storage XP user guide for more information.
Number of copies Maximum of three copies (S-VOLs) per primary volume (P-VOL). Maximum of one
P-VOL per S-VOL (P-VOLs cannot share an S-VOL).
An additional six copies can be created by using the BC cascade function.
Maximum number of
pairs
1
A maximum of 8,192 pairs (8,192 P-VOLs and 8,192 S-VOLs) can be created
per disk array.
NOTE:
The maximum number of pairs equals the total number of BC, Snapshot XP,
ShadowImage for z/OS, Hitachi FlashCopy Mirroring, Hitachi FlashCopy
Mirroring Version 2, Auto LUN XP, and Flex Copy XP volume pairs.
When you use RAID Manager, the command device reduces the maximum
num be r o f B C p a ir s t o 8,191 ( 8,191 P -VO Ls a nd 8,191 S -VO Ls ) wh en con figuring
pairsinaratioof1S-VOLto1P-VOL.
IfsomeBCpairscontainLUSEvolumes,orifanapplicationotherthanBCisused,
the maximum number of BC pairs might be less than 8,192 (or 8,191).
Refer to Maximum number of pairs for the array Maximum number of pairs for
the array” on page 15 for information about calculating the maximum number
of BC pairs.
Maxi
mum number of
S-VO
Ls
8,19
2(8,191ifRAIDManagerisused).
MU (mirror unit) numbers
of cascade pairs
L1 pairs = 0, 1, and 2 (a total of 3 pairs)
L2pairs=1and2(atotalof2pairs)
Combinations of
RAID levels (primary-
secondary)
All combinations supported: RAID1-RAID1, RAID5-RAID5, RAID6-RAID6,
RAID1-RAID5, RAID1-RAID6, RAID5-RAID1, RAID5-RAID6, RAID6-RAID1,
RAID6-RAID5.
Dynamic sparing and
automatic correction
copy
If a
failure occurs requiring the disk array to utilize dynamic sparing or automatic
correction copy, the status of the paired volumes associated with the failed
physical device is not affected.
14
Business Copy XP (BC) for the Array