scsimgr.1m (2010 09)

s
scsimgr(1M) scsimgr(1M)
• 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.
• The
tport_max_qdepth
attribute determines the maximum number of IOs issued to the target port.
If a target port is seen through several target paths,
tport_max_qdepth
can be set and displayed
through any one of the target paths.
Automatic distribution of target port’s maximum queue depth over the servers in a HP ServiceGuard
cluster may happen only if appropriate version of HP ServiceGuard software is installed. Please refer
to HP ServiceGuard release notes for more information. If automatic distribution of target port’s max-
imum queue depth over the servers is desired, it is recommended that you set the same value on all
servers in the cluster for a given target port.
• Setting the value of the
tport_qd_dyn attribute to 1 means the number of IOs issued on a target
path to a target port may be adjusted depending on the demand from the incoming IO load relative to
the demand on other target paths to the same target port. If a target port is seen through several tar-
get paths, tport_qd_dyn can be set and displayed through any one of the target paths.
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.
RETURN VALUE
scsimgr exits with one of the following values:
0 Operation successful.
>0 Error condition occurred.
When an error condition occurs,
scsimgr will display an error message specifying the nature and/or the
cause of the error conditions.
However, for operations supporting scriptable output (when the
-p option is used), no errors will be
printed if the error condition only affects one or more of the output fields. scsimgr will leave the
22 Hewlett-Packard Company − 22 − HP-UX 11i Version 3: September 2010