scsimgr.1m (2011 03)

s
scsimgr(1M) scsimgr(1M)
(1).
To enable/disable dynamic conges-
tion control on the target port of
the target path. Values: false (0)
or true (1). Note: This attribute is
only valid when
tport_qdepth_enable
has
been set to true (1).
tport_qd_dyn RW boolean
Notes:
• Setting the value of attribute
max_q_depth for a LUN, will set the queue depth for all LUN paths of
the LUN to the value specified.
• The queue depth of LUN paths of a LUN can also be changed as follows:
scsictl -m queue_depth
However scsictl -m queue_depth only affects the current value while
scsimgr can set the
value persistently across system reboots.
• If
scsictl is invoked on a persistent DSF, it only affects the current value of all LUN paths. If it is
invoked on a legacy DSF, it only affects the current value of the queue depth on the LUN path
corresponding to the legacy DSF.
• If the current value is changed with the
scsictl command while the LUN is not opened, this value
will be lost when the LUN is opened. The value saved or set at a higher scope with the
scsimgr com-
mand will be restored.
• If the value of the
escsi_maxphys
global attribute is changed, the new value is used for the compu-
tation of the actual maximum I/O size of a given LUN only when one or more of these situations occurs:
• The LUN is opened the first time.
• A new LUN path is registered for the LUN.
• An existing LUN path for the LUN is deleted.
The actual maximum I/O size for a LUN is determined by whichever is the smallest of these two values:
• the
escsi_maxphys attribute or
• the maximum I/O sizes reported by interface drivers on LUN paths of the LUN.
•
tport_alias attribute is a user friendly name also called alias, assigned to the target port of a tar-
get path. If a target port is seen through several target paths, the target port alias can be set and
displayed through any one of the target paths.
The target port alias should comply with the following rules:
• Can have alphabetical and numerical characters but should start with an alphabetical character.
• Cannot have any special characters except
- and _.
• Can have a maximum of 64 characters.
For example "XP24K_PORT0_BLD6_K42" is a valid target port alias, but "3PORT2" and
"XP_24&90" are not.
• If attribute
wrr_path_weight is set to 0 for a LUN path, and the I/O load balancing policy is set to
weighted_rr for the corresponding LUN, the LUN path will not be used for I/O transfer.
• Changes to the
leg_mpath_enable attribute would not affect legacy DSFs that are already open.
• Setting the value of the
tport_qdepth_enable attribute to 1 means the number of IOs to a target
port will be limited to the value of tport_max_qdepth, regardless of the number of LUNs used and
regardless of the max_q_depth attribute on the LUNs. If a target port is seen through several target
paths, tport_qdepth_enable can be set and displayed through any one of the target paths.
tport_qdepth_enable allows for higher values of max_q_depth on LUNs and for higher number
of LUNs.
In a HP ServiceGuard environment, it is recommended that you set the same value on all servers in the
cluster for a given target port.
22 Hewlett-Packard Company − 22 − HP-UX 11i Version 3: March 2011