Enterprise Linux the very term usually refers to some type of storage area network normally fiber channel. In all my experience I have not yet met a storage administrator who went to formal storage training. So it’s no doubt that there are some weaknesses when it comes to storage with linux. Here are some of the storage basics. This article assumes you already have a working knowledge of WWID’s, WWN’s and fiber channel storage.
There are multiple WWID’s involved in the process here are a few:
As you can see we need a lot of WWID’s to make fiber channel storage work. This article will focus on getting the Storage LUN WWID from the server. This will allow us to identify our mount points to storage LUN’s.
First thing to identify is the SCSI WWID this is used by Linux Native Multipathing (MPIO) this is found by using the following command (for device sda):
scsi_id -g -u -s /block/sda
This will return the SCSI device WWID not to be confused with any other WWID’s. If you want to know more information about the device you can get a manufactures label by using:
scsi_id -g -u /dev/sda
A lot of this information is stored in /dev/disk in various directories:
[table id=3 /]
The information we want is inside /dev/disk/by-path which looks like this:
lrwxrwxrwx 1 root root 10 Jan 22 13:48 scsi-38001438005dea3760000700002660000 -> ../../sdfj
So in this case the SCSI WWID is 38001438005dea3760000700002660000 while the LUN WWID is :
That’s about it. Now just tie that to your storage system.