iSCSI Qualified Name (iQN) naming format, how to pick

Hi Guys!

This might be dead obvious to some of you out there, but for me just starting in the world of storage (Currently studying for my EMC VNX Storage certification :)), some of this was less than obvious, I wanted to quickly talk about iSCSI.

In iSCSI, your initiator and target (your host and the storage your host is trying to talk to) have names, these names are called iSCSI Qualified Names (IQN) and have a particular format, I never really understood how the format was meant to work and although wikipedia kind of shows you I think a more laymen definition would be helpful :)

So an IQN has the following format:

iqn.date.yourdomainname-in-reverse:storage-identifer

so the start of the IQN must start with IQN, this is required, next you enter a date, and a domain name, this is where I was confused, what domain name do I use?

you can use any domain name that belongs to your organization, even a domain name that has expired or does not resolve to anything, the date part of the above string, is where you specify a date (in format of YYYY-MM) on which you owned that domain name, so let's say i had the domain name ccierants.com on the 5th month of 2011 my format would be

iqn.2011-05.com.ccierants

Again, the domain does NOT have to resolve, and i don't even have to own it anymore, i just have to have owned it on that date, I am not sure what the rules around internal domain names would be (maybe you've never registered a domain, which seems quite odd, but let's hypothetically say that is the case) but i assume it is generally frowned upon.

That is the start of my IQN, then the identifer after the : (shown as storage identifer in my little bit above) can be anything that makes sense to you as an organization, it could be a serial number, an asset number or any other storage identifier.

so the total string is:

iqn.2011-05.com.ccierants:emc-vnx-prod-01

for example :)




I hope this clears things up for someone, I actually found this out thanks to an EMC Book, it seems quite obvious now but for me it was something I did not fully know :).