Scanning for luns presented to Linux box

[Waqar Razi]

I am an HPUX admin and in HPUX, we use ioscan command to scan for new LUNs presented to an HPUX system. How can I see the LUNS presented to a Linux box. Lets say, storage admin have presented some luns to linux bix, what are the steps to make them seen in linux (RHEL).

[Ivan Ferreira]

Please see this thread:

http://forums11.itrc.hp.com/service/forums/questionanswer.do?threadId=1060267

[John McNulty_2]

What version of Redhat ?

[Waqar Razi]

REd hat enterprise 4

[Tony Cicone]

Attached script is recommended by HP for rescanning scsi bus.

[Colin Topliss]

I've found that sometimes you need to reboot the server before you can see the luns. Otherwise you can use the utils with the PSP (if you're brave enough to install it), or try rescanning the bus by (for example):

echo "scsi-qlascan" > /proc/scsi/qla2300/0
/bin/rescan-scsi-bus.sh

You might need to supply params to the rescan-scsi-bus.sh script - might depend on your hardware. You also have to have the rescan script :-)

To scan all channels, targets and LUNs, you could also try:

echo "- - -" > /sys/class/scsi_host/host0/scan

Not sure if this works with FC attached LUNs - I had a weird error on the test system, but our EVA has been behaving strangely over the past few days :-(

Once the LUNs can be seen, then Linux does the rest. You should be able to fdisk them, pvcreate them, or do whatever you want. xpinfo or evainfo (depending on what you have) will show you which devices you now have mapped.

[Emil Velez]

try
# hwinfo

its on suse by default i know of and as another HPUX guy it seems to be somewhat equivilent.

I also use

# lvmdiskscan

[Fayez]

Hi,

As Colin said, most time you have to restart the server after presenting new luns to the linux.

[SJO EGGER]

echo "- - -" > /sys/class/scsi_host/hostX/scan

this way works really fine and i make the same one in my scripts. make sure you do this for every HBA on your system.

no problem on SLES9/10/11.

roland