1.First find out how many disks are visible in “fdisk -l” .
# fdisk -l 2>/dev/null | egrep '^Disk' | egrep -v 'dm-' | wc -l
2.Find out how many host bus adapter configured in the Linux box.you can use “systool fc_host -v” to verify available FC in the system.
# ls /sys/class/fc_host
host0
host1
In this case,you need to scan host0 & host1 HBA.
3.If the system virtual memory is too low ,then do not proceed further.If you have enough
free virtual memory,then you can proceed with below command to scan new LUNS.
# echo "1" > /sys/class/fc_host/host0/issue_lip
# echo "- - -" > /sys/class/scsi_host/host0/scan
# echo "1" > /sys/class/fc_host/host1/issue_lip
# echo "- - -" > /sys/class/scsi_host/host1/scan
Note: You need to monitor the “issue_lip” in /var/log/messages to determine when the
scan will complete.This operation is an asynchronous operation.
You can also use rescan-scsi-bus.sh script to detect new LUNS.
# yum install sg3_utils
# ./rescan-scsi-bus.sh
4.Verify if the new LUN is visible or not by counting the available disks.
# fdisk -l 2>/dev/null | egrep '^Disk' | egrep -v 'dm-' | wc -l
If any new LUNS added ,then you can see more count is more then before scanning the
LUNS.
Scanning SCSI DISKS in Redhat Linux
1.Finding the existing disk from fdisk.
[root@mylinz1 ~]# fdisk -l |egrep '^Disk' |egrep -v 'dm-'
Disk /dev/sda: 21.5 GB, 21474836480 bytes
2.Find out how many SCSI controller configured.
[root@mylinz1 ~]# ls /sys/class/scsi_host/host
host0 host1 host2
In this case,you need to scan host0,host1 & host2.
3.Scan the SCSI disks using below command.
[root@mylinz1 ~]# echo "- - -" > /sys/class/scsi_host/host0/scan
[root@mylinz1 ~]# echo "- - -" > /sys/class/scsi_host/host1/scan
[root@mylinz1 ~]# echo "- - -" > /sys/class/scsi_host/host2/scan
4.Verify if the new disks are visible or not.
[root@mylinz1 ~]# fdisk -l |egrep '^Disk' |egrep -v 'dm-'
Disk /dev/sda: 21.5 GB, 21474836480 bytes
Disk /dev/sdb: 1073 MB, 1073741824 bytes
Disk /dev/sdc: 1073 MB, 1073741824 bytes
From Redhat Linux 5.4 onwards, redhat introduced “/usr/bin/rescan-scsi-bus.sh” script to scan all the
SCSI bus and update the SCSI layer to reflect new devices.
But most of the time,script will not be able to scan new disks and you need go with echo command.
Do not forget to check out Redhat Enterprise Linux 7 Tutorial .
Here is the step by step guide to scan FC LUNS on Solaris.
Thank you for reading this article.
# ls /sys/class/fc_host
host0 host1
#echo "1" > /sys/class/fc_host/host0/issue_lip
#echo "- - -" > /sys/class/scsi_host/host0/scan
#echo "1" > /sys/class/fc_host/host1/issue_lip
#echo "- - -" > /sys/class/scsi_host/host1/scan
AIX
HP-UX
Linux
Solaris
1. cfgmgr -v
2. vxdctl -f enable
1. ioscan -fnC disk
2. insf -C disk
3. vxdctl -f enable
1. /usr/bin/rescan-scsi-bus.sh
2. vxdctl -f enable
1. cfgadm -c configure <controller>
2. devfsadm -Cv
3. vxdctl -f enable
Scanning FC/SAN LUNS in Solaris
Before scanning LUNS, we see some useful commands which are related to Fibre Channel(FC).
1.List the connected HBA’s.
root@Unixarena-SOL11:~# luxadm -e port |grep CONNECTED
/devices/pci@1d,700000/SUNW,qlc@1,1/fp@0,0:devctl CONNECTED
/devices/pci@1d,700000/SUNW,qlc@3/fp@0,0:devctl CONNECTED
2.Verify FC channel ‘s are connected and configured.
Unix@sol# cfgadm -al -o show_FCP_dev |grep fc-fabric
c2
fc-fabric
connected
configured
unknown
c4
fc-fabric
connected
configured
unknown
Unix@sol#
3.To find the HBA’s World wide Node number (WWN),use fcinfo command,
Unix@sol# fcinfo hba-port |grep Port
HBA Port WWN: 10000000c884bb48
HBA Port WWN: 10000000c884bb49
HBA Port WWN: 10000000c884b85c
HBA Port WWN: 10000000c884b85d
Unix@sol#
4.You can also find the WWN form luxadm command, if HBA is already connected to FC switch.
Unix@sol# luxadm -e dump_map /dev/cfg/c4
Pos
Port_ID Hard_Addr Port WWN
Node WWN
Type
0
29900
0
50080e8008cfb814 50080e8008cfb814 0x0
1
27400
0
10000000c884b85c 20000000c884b85c 0x1f (Unknown Type,Host Bus Adapter)
(Disk device)
Unix@sol#
From the above output, the last line shows the HBA information.In the same you can find the other
controller information as well.
5.Zoning can be verified using the below command.
Unix@sol# cfgadm -al -o show_FCP_dev c2 c4
6.If you see any controller port “WWN” showing as “unconfigured” ,then you can initiate FC session
using below mentioned command.
Unix@sol# cfgadm -c configure c2::50080e8008cfb814
Unix@sol# cfgadm -c configure c4::50080e8008cfb814
Let’s see how we can re-scan the SAN/FC luns on solaris 10/11 hosts.
To scan new FC luns, Just execute the below commands.
Scanning FC/SAN LUNS
1
cfgadm -al
To scan FC luns
2
devfsadm -c disk
To make sure all the device files are create
3
tail /var/adm/messages
To see the new LUN’s information
4
echo |format
To get the new LUN’s information
5
ls -lrt /dev/rdsk |grep s2|tail
To get the new LUN’s information
“luxadm probe” also used to scan FC luns but i am happy to use cfgadm.
If you still not able to see the new LUNS/DISK ,then you can try to reset the HBA as last option if you
have multipath enabled. (Do not try in critical servers unless you have confident on multipathing)
1.List the connected HBA.
root@Unixarena-SOL11:~# luxadm -e port |grep CONNECTED
/devices/pci@1d,700000/SUNW,qlc@1,1/fp@0,0:devctl CONNECTED
/devices/pci@1d,700000/SUNW,qlc@3/fp@0,0:devctl CONNECTED
2.Reset the HBA using forcelip option.
root@Unixarena-SOL11:~# luxadm -e forcelip /devices/pci@1d,700000/SUNW,qlc@1,1/fp@0,0:devctl
Forcelip can be issued to the controller names as well.
Unix@sol# cfgadm -al -o show_FCP_dev |grep fc-fabric
c2
fc-fabric
connected
configured
unknown
c4
fc-fabric
connected
configured
unknown
Unix@sol#
Unix@sol# luxadm -e forcelip /dev/cfg/c2
3. Verify the controller status using “cfgadm -al”.Make sure disks didn;t loose any SAN paths after the
HBA reset. If everything seems to be okay ,then isssue the forcelip to the another controller.
If still you are not able to see the new FC/SAN LUNS ,then reboot the server and try. Once you see
the new lun, make sure that multiple FC paths are enabled to that. Minimum two FC paths required
for SAN disks.
” luxadm display /dev/rdsk/c1txxxxxxd0s2″ – To verify the FC lun details and multipathing.