Scanning for new luns

Published 11 Feb 2011 Read time 1 min 42 sec(s) (2560 views). Storage

This is a short article on how to rescan newly added luns in Solaris, Linux, AIX and HP-UX operating systems.

Solaris

Determine the FC channels
```
cfgadm -al
```
Force rescan
```
cfgadm -o force_update -c configure -c#
```
where # is the FC channel number
Force rescan at HBA port level
```
luxadm -e forcelip /dev/fc/fp#
```
Force rescan on all FC devices
```
cfgadm -al -o show_FCP_dev
```
Install device files
```
devfsadm
```
Display QLogic HBA ports
```
luxadm -e port
```

Disaply HBA port information

luxadm -v disable WWPN
luxadm -e dump_map

Linux

A Linux system can recognize newly attached LUNs without unloading the FC HBA driver. The procedure slightly differs depending on the installed FC HBAs.

In the case of QLogic HBAs, issue the command

echo “scsi-qlascan > /proc/scsi/qla2300/<adapter-instance>

With Emulex HBAs, issue the command
```
sh force_lpfc_scan.sh “lpfc<adapter-instance>”
```
This script is not part of the regular device driver package, and you must download it separately from the Emulex website. It requires you to install the tool dfc under /usr/sbin/lpfc.
In both cases, you must issue the command for each installed HBA with the <adapter-instance> for the SCSI instance number of the HBA.
After the FC HBAs rescan the fabric, you can make the new devices available to the system by running the command
```
echo “scsi add-single-device s c t l” > /proc/scsi/scsi
```
The quadruple s c t l is the physical address of the device:
- s is the SCSI instance of the FC HBA.
- c is the channel (in our case, always 0).
- t is the target address (usually 0, except if a volume is seen by a HBA more than once).
- l is the LUN
.

AIX

Rescan the devices
```
cfgmgr -vi fcs#
```
where # is the FC adapter number
Verify the new devices
```
lsdev -Cc <disk|tape>
```

HP-UX

Rescan devices
```
ioscan -fnC <disk|take>
```
Generate device files
```
infs -e
```
Verify the new devices
```
ioscan -funC <disk|tape>
```