When at a storage event or even responding to comments, every so often a
specific question comes up about which protocol, drive type, backup
application should a user implement for their specific environment. The
answer that should come back most often is "it depends" because that's
the truth.The reality is that for most situations, you can get almost anything to work.
Its a matter of how hard you have to work at it.
For example, if you are
setting up your first virtualization project, you can get it going and
get two hosts talking with the same amount of ease/difficulty on
iSCSI as you can on NAS, AoE, SAS or...dare I say it?...Fibre Channel. The test for any of these environments is how they change as the environment scales? When you
have 50 hosts with 500 virtual machines, the complexities of these
different protocol options and the storage systems that support them
become important factors in the amount of time spent managing storage.
Conversely, if you only have $5k to spend, all the amazing things that a
$50k SAN does really doesn't matter, you're going to have to make
that $5k solution work.
Beyond the obvious budget issues, it just depends on how far you
are going to take whatever project you are working on. In my experience,
the greater the demand for either performance, scale or longevity, the
more important it is to understand the differences between these technologies. Storage systems and protocols that can address more needs
are almost always the more expensive solutions. Something that is cheap
and easy to install may not be easy to operate when 500 virtual machines
are pounding on it.
I should put in the obligatory suggestion that after you have read as
much as you can and have asked a lot of questions, you eventually have to do
your own testing. Labs can be as much of a pain to keep together as
production systems sometimes, and they still don't tell you everything
that will happen in production. Also, I'm sensitive to the reality that
as a user, you are stretched thin as ever. The time to properly evaluate
the top three or four vendors in a space just doesn't exist any more.
Lately we've advised the vendors to expect very
long test cycles. You can only test so much in 30 days, and it is really
not indicative of how the system is working. Ask me about a system that
we have had in the lab for three or four months is working, and I can give a
much more confident assessment. You can take comfort in the fact that most storage systems can be made
to work. The amount of research and investigative work you do is the key
to how difficult it will be.
