Installation guide

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 --no flush device_name

After you resize your storage and take it back online, you must run the following command before

resizing your paths:

# dmsetup resume device_name

Chapter 5. DM-Multipath Administration and Troubleshooting