HP XP P9500 Storage - Manual (Page 11)

Table 5 Behavior of storage system - block option is “Cache Level”
Behavior of the P9500 disk array Compatible XRC Options
Do not Block is Not specified by SDM (Block
is specified) or Do not Block (Volume Level)
is disabled Do not Block is specified by SDM and Do not
Block (Volume Level) is enabled Setting Option
If Level 1 Sleep is enabled, the disk array
reports a SIM to the host when the amount The disk array does not report a SIM to the
host when the amount of used sidefile
capacity exceeds the sleep wait threshold. Enable Level 1 SIM
of used sidefile capacity exceeds the sleep
wait threshold.
If Level 1 Sleep is disabled, the disk array
does not report a SIM to the host when the
amount of used sidefile capacity exceeds
the sleep wait threshold.
The disk array does not report a SIM to the
host when the amount of used sidefile
capacity exceeds the sleep wait threshold. Disable
The disk array performs "Sleep" - "Wait"
command retry when the sleep wait
threshold is exceeded. The disk array does not perform "Sleep" -
"Wait" command retry.
Level 2 Suspend does not occur when the
amount of used sidefile capacity exceeds
Enable Level 1
Sleep
Disable Level 2
Suspend
Level 2 Suspend does not occur when the
amount of used sidefile capacity exceeds
the level 2 threshold. And the disk array
does not report SCP-SCI to the host.
*1, *3
the level 2 threshold. And the disk array
reports SCP-SCI to the host.
*2
(The disk array restricts the host I/O data
flow to prioritize the retention of XRC pair
status when the used sidefile capacity is
overloaded.)
The disk array performs "Sleep" - "Wait"
command retry when the sleep wait
threshold is exceeded. Disable Level 1
Sleep
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.)
*1
When you specify the [Do not Block] in the Xaddpair command parameter, enable the [Do
not 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 [Do not 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 to each CLPR. If
an SC session extends over more than one CLPR, the storage system operates depending on the
Compatible XRC option setting for each CLPR. For example, if more than one session exists in one
CLPR and the amount of used sidefile capacity in the CLPR reaches level-2 (if the Level 2 Suspend
option of Compatible XRC is enabled) or level-3, the session that occupies the largest capacity in
the sidefile in the cache is suspended.
Restrictions on usage 11