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HP Hitachi Dynamic Link Manager Software User Manual

Page 361

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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.

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