Hitachi Dynamic Link Manager Software Users Guide for Linux

• If an LU is allocated and another LU is reallocated using the same host LU
number, HDLM does not handle them as different LUs. Therefore, restart
the host whenever a configuration change is made.
• When two or more HDLM devices are specified with the -s parameter, the
confirmation message is not displayed each time the processing for each
HDLM device is executed. For example, when this utility executes an
operation specified with the -o parameter for /dev/sddlmaa, /dev/
sddlmab, and /dev/sddlmac, the confirmation message KAPL10339-I is
not displayed for the processing of each device. This message is displayed
once at the beginning of the operation. If you enter y, the processing for
all the specified HDLM devices (/dev/sddlmaa, /dev/sddlmab, and /dev/
sddlmac) is executed continuously.
• After changing partition configuration directly from a SCSI device for LUs
corresponding to the HDLM devices not to be managed, if the HDLM
device is returned to management target, execute the following
operations:
a. Execute the dlmcfgmgr utility with the -i parameter specified.
b. Execute the dlmcfgmgr utility with -r parameter specified.
• If you execute the dlmcfgmgr utility with the -i parameter specified, the
HDLM device that is not a management target can be changed to a
managed status. At this time, if an error occurs anywhere on the paths to
an HDLM device and you change that HDLM device to a managed status,
the message KAPL08026-E might be output to the syslog. However, HDLM
operations are not affected.
• If you execute the dlmcfgmgr utility with the -r parameter specified, the
I/O and I/O error counts for existing paths displayed when the HDLM
command (dlnkmgr view -path) is executed are initialized to 0.
• If an HDLM device that is managed on the active host is changed to be
managed on the standby node, and then the same HDLM device is
excluded from management on the standby node then, during the cluster
creation, an error will occur when the active node is failed over. When the
dlmcfgmgr utility is executed with the -o parameter specified to exclude
an HDLM device from management on the standby node, make sure that
you exclude the same HDLM device from management on the active
node.
• When an HDLM device is bound to a raw device, do not attempt to
exclude that HDLM device from management by executing the dlmcfgmgr
utility with the -o parameter specified. If the HDLM device is not being
managed, an error will occur when the raw device is accessed.
• After configuring an HDLM device by executing the dlmcfgmgr utility, do
not change the settings of the sysfs interface that handles SCSI devices.
• After configuring an HDLM device by executing the dlmcfgmgr utility, if
you unload the HBA driver, perform the following operations. If you load
the HBA driver without first performing the operations, the number of
HDLM paths that cannot be used might increase.
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Utility Reference
Hitachi Dynamic Link Manager (for Linux®) User Guide