Hitachi Dynamic Link Manager Software Users Guide for Linux (6.6) (HIT5203-96005, November 2011)

• SCSI devices corresponding to an HDLM device can be removed
dynamically even while the HDLM device is in use. Before doing so,
perform the following operations:
a. Unmount any devices mounted on the HDLM device.
b. 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
• Before you update the OS SP, uninstall HDLM. After you have updated the
OS SP, re-install HDLM.
For details on HDLM installation and uninstallation, see
Installing HDLM on
page 3-75
and
Uninstalling HDLM on page 3-216.
•
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.
Notes When Using SUSE LINUX Enterprise Server 10
Note the following when your OS is SUSE LINUX Enterprise Server 10:
• Before you update the kernel package, uninstall HDLM. After you have
updated the kernel package, re-install HDLM.
For details on HDLM installation and uninstallation, see
Installing HDLM on
page 3-75
and
Uninstalling HDLM on page 3-216.
•
SCSI devices corresponding to an HDLM device can be removed
dynamically even while the HDLM device is in use. Before doing so,
perform the following operations:
a. Unmount any devices mounted on the HDLM device.
b. Execute the dlmcfgmgr -o command to exclude the HDLM device
from management.
• HDLM devices cannot be used to create an md device.
4-6
HDLM Operation
Hitachi Dynamic Link Manager User Guide (for Linux(R))