HP Hitachi Dynamic Link Manager Software User Manual
Page 361
4. HDLM Operation
337
1.
Unmount any devices mounted on the HDLM device.
2.
Execute the
dlmcfgmgr -o
command to exclude the HDLM device from
management.
HDLM devices cannot be used to create an md device.
If you execute the
sync
command on the file system that is mounted by ext3/
ReiserFS, the following message is output to syslog, but there is no problem with
HDLM operations.
JBD: barrier-based sync failed on sddlmaa1 - disabling
barriers
If the number of I/O operations that have occurred in the system exceeds the
execution performance of the system (in an environment in which all of the
conditions below exist), the KAPL05008-E message and the call trace of a kernel
might be output.
• Hitachi WMS exists in HDLM management-target devices.
• In the utility for setting HDLM driver option (
dlmsetopt
), the number of
retries for allocating memory is set to 0 through 2,147,483,646.
In this case, the system might become unstable, and an error might occur in the I/
O that is being executed. In the
dlmsetopt
utility, set -1 or a value greater than
the current value for the number of retries for allocating memory, and then restart
the system. If a call trace is output even after the retry count is set to -1, consider
adding memory and stopping unnecessary processes.
When a device is dynamically configured by using the udev function, the error
message KAPL05023-E might be output to the console or syslog. However,
HDLM operations are not affected.
When the
dlmcfgmgr
utility is executed with the
-r
parameter specified, the
error message KAPL05023-E is output to the syslog file. However, HDLM
operations are not affected.
Sometimes a hyphen is displayed for the SCSI device name in the
Device
column of the results of the
dlmcfgmgr
utility (
dlmcfgmgr -v
) or the view
operation of the HDLM command (with either the
-lu
or
-drv
parameter
specified). This might happen if one of the problems listed below occurs while the
system is running, even if the SCSI devices are not erased. This problem is related
to the OS's hot-plug function. HDLM operations are not affected:
• A path gets disconnected.
• An LU is deleted.
• A fiber cable connection is changed.