Resizing An Online Multipathed Device (Rhel 4.8 And Later) - Red Hat ENTERPRISE LINUX 4 - DM MULTIPATH Manual

Chapter 5. DM-Multipath Administration and Troubleshooting
> > CTRL-D
The following command sequence ensures that multipath has picked up any changes to the
multipath.conf,
# multipathd -k
> > reconfigure
> > CTRL-D
Use the following command sequence to ensure that the path checker is working properly.
# multipathd -k
> > show paths
> > CTRL-D
5.6. Resizing an Online Multipathed Device (RHEL 4.8 and
later)
In systems running RHEL 4.8 and later, is is possible to resize a multipath device while it is online.
This allows you to resize the device when it is open, as when a file system is currently mounted.
Use the following procedure to resize an online multipath device.
1. Resize your physical device.
2. Resize your paths. For SCSI devices, writing a 1 to the rescan file for the device causes the
SCSI driver to rescan. You can use the following command:
# echo 1 > /sys/block/device_name/device/rescan
3. Resize your multipath device by running the multipath command:
# multipath
Your hardware setup may require that you temporarily take the actual storage offline in order to resize
your physical device. If you take your storage offline and your multipath device is not set to queue
when all paths are down, any I/O activity while your storage is offline will fail. You can work around this
by executing the following command before taking your storage offline:
# dmsetup suspend --noflush device_name
After you resize your storage and take it back online, you must run the following command before
resizing your paths:
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