Hitachi Dynamic Link Manager Software Users Guide for Linux

how to migrate an md device for which the MULTIPATH function is used to an
md device for which the LINEAR function is used.
Note:
Red Hat Enterprise Linux 6 cannot migrate an md device for which the
MULTIPATH function is used to an md device for which the LINEAR function
is used.
In this procedure, the device /dev/md0 on /dev/sdo1 and /dev/sdh1 is
migrated to the device /dev/md0 on /dev/sddlmaa1. Use the following
procedure to configure the environment shown in
Figure 3-13 Device
Configuration Where an md Device (An Environment that Uses the md
Device's MULTIPATH Function) on a SCSI Device Is Migrated to an md Device
on an HDLM Device on page 3-168.
Figure 3-13 Device Configuration Where an md Device (An Environment
that Uses the md Device's MULTIPATH Function) on a SCSI Device Is
Migrated to an md Device on an HDLM Device
To migrate /dev/md0
1. Stop all applications that are using the existing md device.
2. If necessary, back up the application data residing on the md device.
3. If file systems have been mounted on the md device, unmount them.
4. Check the status of the md device.
Execute the following command to check the configuration of the md
device:
# cat /proc/mdstat
Personalities : [multipath]
md0 : active multipath sdo1[0] sdh1[1]
5238528 blocks [2/2] [UU]
unused devices: <none>
Make sure that md0 : active and that SCSI devices are displayed.
If md0 : active is not displayed, activate the md device.
3-168
Creating an HDLM Environment
Hitachi Dynamic Link Manager (for Linux®) User Guide