How to delete multiple Linux DM-MPIO (Device Mapper - Multi Path IO ) devices from a Linux system?
From below command output, find wwid of multipath devices you want to remove and list them in a file.
multipath -l |grep dm-
vi /tmp/wwid_of_multipath_devices_to_delete.txt
cat /tmp/wwid_of_multipath_devices_to_delete.txt
Verify the details of devices you are going to remove
while read i ; do multipath -ll $i ; done </tmp/wwid_of_multipath_devices_to_delete.txt
Collect LUN's scsi ID of multipath devices you are going to delete
while read i ; do
multipath -l $i|grep -E "[0-9]{1,2}:{1,4}"|awk '{print $2}'|awk '{print $2}'
done </tmp/wwid_of_multipath_devices_to_delete.txt | sort -u > /tmp/disks_scsi_id.txt
cat /tmp/disks_scsi_id.txt
Ensure multipath devices are not used on system. Flush multipath device information
multipath -ll > multipath-output-pre.txt
multipath -ll | grep -E "$(cat wwid_of_multipath_devices_to_delete.txt |grep -v "^$"|tr '\n' '|')xxxxyyy"|awk '{print $1}' | tee multipath_disk_alias_name.txt
cat multipath_disk_alias_name.txt
while read i ; do
multipath -f $i
echo "$i flushed"
done </tmp/multipath_disk_alias_name.txt
multipath -ll > multipath-output-post.txt
diff multipath-output-pre.txt multipath-output-post.txt
Now they should NOT be seen in multipath output
while read i ; do
multipath -ll > multipath-output-post.txt
diff multipath-output-pre.txt multipath-output-post.txt
Now they should NOT be seen in multipath output
while read i ; do
multipath -ll $i
done </tmp/wwid_of_multipath_devices_to_delete.txt
Delete LUN details from the Linux Kernel
while read j ; do
echo 1 > /sys/bus/scsi/drivers/sd/$j/delete
echo "$j deleted"
done </tmp/disks_scsi_id.txt
Delete the device information from /etc/multipath.conf
cp -a /etc/multipath.conf /etc/multipath.conf.ORG
vi /etc/multipath.conf
Restart multipathd and verify that the disks have been deleted and no more recognized by multipathd. Below should not list any device
service multipathd restart
while read i ; do multipath -ll |grep $i ; done </tmp/wwid_of_multipath_devices_to_delete.txt
while read i; do ls -l /dev/mapper/|grep $i; done </tmp/wwid_of_multipath_devices_to_delete.txt
Unmask LUN from system on Storage SAN Switch/Frame
If you decide to add the LUNs again on same system, mask the LUN on system, rescan the BUS and add them in multipath.conf
for i in $(ls /sys/class/scsi_host/) ; do echo - - - > /sys/class/scsi_host/$i/scan ; done
service multipathd restart
multiptah -ll | grep dm-
vi /etc/multipath.conf
service multipathd reload
References
http://www.kernel.org/doc/ols/2005/ols2005v1-pages-155-176.pdf
http://en.wikipedia.org/wiki/Linux_DM_Multipath
Delete LUN details from the Linux Kernel
while read j ; do
echo 1 > /sys/bus/scsi/drivers/sd/$j/delete
echo "$j deleted"
done </tmp/disks_scsi_id.txt
Delete the device information from /etc/multipath.conf
cp -a /etc/multipath.conf /etc/multipath.conf.ORG
vi /etc/multipath.conf
Restart multipathd and verify that the disks have been deleted and no more recognized by multipathd. Below should not list any device
service multipathd restart
while read i ; do multipath -ll |grep $i ; done </tmp/wwid_of_multipath_devices_to_delete.txt
while read i; do ls -l /dev/mapper/|grep $i; done </tmp/wwid_of_multipath_devices_to_delete.txt
Unmask LUN from system on Storage SAN Switch/Frame
If you decide to add the LUNs again on same system, mask the LUN on system, rescan the BUS and add them in multipath.conf
for i in $(ls /sys/class/scsi_host/) ; do echo - - - > /sys/class/scsi_host/$i/scan ; done
service multipathd restart
multiptah -ll | grep dm-
vi /etc/multipath.conf
service multipathd reload
References
http://www.kernel.org/doc/ols/2005/ols2005v1-pages-155-176.pdf
http://en.wikipedia.org/wiki/Linux_DM_Multipath
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