HP XP7 Storage - Manual (Page 12)

Behavior of the HP XP7 Storage disk array Compatible XRC Options
Donot Block is Not specified by SDM (Block
is specified) or Donot Block (Volume Level)
is disabled Donot Block is specified by SDM and Donot
Block (Volume Level) is enabled Setting Option
Enable Level 2
Suspend Level 2 Suspend occurs when the amount of
used sidefile capacity exceeds the level 2
threshold.
3
(The disk array suspends the XRC pair to
prioritize the retention of host I/O
performance when the used sidefile capacity
is overloaded.)
Notes:
1. When you specify the Donot Block in the Xaddpair command parameter, enable the Donot Block in the
Compatible XRC option settings.
2. When you prioritize the retention of XRC pair status, set the Level 1 Sleep to Enable and Level 2 Suspend
to Disable.
3. When you prioritize the retention of host I/O performance, specify the Donot Block, or set the Level 1 Sleep
to Disable and Level 2 Suspend to Enable.
Multiple CLPR use
If you want to use Compatible XRC and more than one cache logical partition (CLPR), we recommend
that you use SC sessions in the same CLPR. Compatible XRC options can be set for each CLPR. If
there are sessions in CLPR, when the sidefile usage for CLPR reaches level-2 (if the Level 2 Suspend
option of Compatible XRC is enabled) or level-3, sessions containing the maximum number of
sidefiles in the cache are suspended. If you want to use Compatible XRC in CLPRs, and if you
assign MP blades to LDEVs that are used as utility volumes, we recommend assigning different MP
blades to each CLPR.
3390-A and 3390-M devices
To use a 3390-A or 3390-M device as Compatible XRC P-VOL or S-VOL, apply the System Data
Mover (SDM) software at the secondary site with the following PTFs (program temporary fixes):
•
z/OS V1R6:[PTF]UA18053: SUPPORT XRC VOLUME SIZE UP TO 65520 CYL
•
z/OS V1R5:[PTF]UA18052: SUPPORT XRC VOLUME SIZE UP TO 65520 CYL
•
z/OS V1R4:[PTF]UA18051: SUPPORT XRC VOLUME SIZE UP TO 65520 CYL
If this PTF has not been applied to the SDM, the 3390-A or 3390-M devices cannot be used as
P-VOLs or S-VOLs in Compatible XRC operations.
Offline microcode replacement or volatile PS-ON
If one of following actions is performed while Compatible XRC is operating, the storage control
(SC) session of the storage system will be automatically terminated:
•
Offline microcode replacement is performed, requiring a power cycle of the storage system.
•
The information in the cache memory is not maintained across the power cycle. This is called
a “volatile PS-ON.”
When this session is terminated, the session of the SDM side of the secondary site is suspended
but the following RESUME operation may fail. To avoid the RESUME failure:
•
Before replacing the microcode offline, delete all Compatible XRC pairs with the XDELPAIR
command before PS OFF, and then create all pairs again with the XADDPAIR command after
PS ON.
•
When performing volatile PS ON, delete all Compatible XRC pairs with the XDELPAIR command
immediately after PS ON, and then create all pairs again with the XADDPAIR command.
12 Requirements and restrictions