Troubleshooting - Red Hat ENTERPRISE LINUX - ONLINE STORAGE RECONFIGURATION GUIDE BETA Configuration Manual

The process is different, however, if a device uses the fibre channel protocol and the
blocked. In such cases, the drivers wait for several seconds for the
again before activating the error handler. This prevents devices from becoming offline due to
temporary transport problems.
Device States.
To display the state of a device, use:
cat /sys/block/<device name>/device/state
To set a device to
running
echo running > /sys/block/<device name>/device/state
Command Timer.
To control the command timer, you can write to
To do so, run:
echo <value> /sys/block/<device name>/device/timeout
Here, is the timeout value (in seconds) you want to implement.
<value>
Alternatively, you can also modify the timeout
/etc/udev/rules.d/50-udev.rules
ACTION=="add", SUBSYSTEM=="scsi" , SYSFS{type}=="0|7|14", \
RUN+="/bin/sh -c 'echo 60 > /sys$$DEVPATH/timeout'"
refers to the timeout length, in seconds; in this case, timeout is set at 60 seconds.
echo 60
Replace this value with your desired timeout length.
Note that the default timeout for normal file system commands is 60 seconds when
being used. If is not in use, the default timeout is 30 seconds.
udev

9. Troubleshooting

This section provides solution to common problems users experience during online storage
reconfiguration.
LUN removal status is not reflected on the host.
When a LUN is deleted on a configured filer, the change is not reflected on the host. In such
cases, commands will hang indefinitely when
lvm
now become stale.
To work around this, perform the following procedure:
state, use:
/sys/block/<device name>/device/timeout
udev
. You should find the following lines:
rport
rule. To do so, open
is used, as the LUN has
dm-multipath
Troubleshooting
is
rport
to become online
.
is
udev
13