The real cost of storage

wyhlg

                存储的价格需要两个方面来衡量：
1：采购时单位容量的价格
2：维护的费用，包括维护的人员费用，厂商的维护费用等等..
What's the real cost of storage? I get asked this
question all the time, and it's so difficult to answer because it
really does depend on so many factors from storage team to storage
team. What's really surprising to me is that I'm being asked the
question at all. You would think that everyone who runs a storage
organization would know exactly what that number is. Some people simply
look at their budget and say "here you go, this is what it costs". But
can you break it down? Do you know where all of that money is going,
and why? I think that's really what people are asking. They know how
much they are spending, but they want to know why and how they can save
money. Certainly in these economic times storage managers are asked to
do more with less while the data continues to grow. So that leaves them
asking, how? How do I manage to address this growing pile of data with
fewer people, less CAPEX budget, and more demands from the business
around things like disaster recovery?
So how do you address
the question? How do you do more with less? A lot of storage managers
are looking at the cost per GB of their disks and asking, can I get
this number down? I think that they can, but it may mean doing some
things in different ways than they have in the past. Specifically, here
are some things to look at.
Tiered Storage

Yup,
I'm recycling that idea again. Getting data off expensive spinning disk
and onto cheaper disk saves money, I think that's been well established
and taking another look at how you are classifying your data is a
worthwhile endeavor at this point in time. Why? Because things have
changed in the last year or two, and those changes might have an impact
on your data classification policies, so I think a review might be in
order. For example, a few years ago when I was classifying data I used
SATA disk pretty much just for dev/test and archive data. But things
have changed, and now there's technology out there that will allow you
to use SATA disk for some of your production workload. Some technology
that will even allow you to use SATA drives for all but your most
demanding workloads for that matter the IBM's new XIV are now
available. So, another look at your tiering policies and the SATA
technology that's available today is probably a good use of your time
if you're looking to save some money.
Cost of Managing Your Storage

What
does it really cost to manage your storage on a per GB basis? This is
really the age old question of "how many TB of storage can a single
storage admin administer?" that we have been asking for a long time.
The answer to this question is critical since you probably aren't
getting a whole lot more headcount right now, and you might even be
asked to give some up. So how do you manage more disk space with the
same or fewer people? First, you have to keep in mind all of the things
that go into managing a TB of space. There's a lot more to it than just
provisioning a TB to an application and then walking away, right? Here
are a few examples of the kinds of things that go into managing a TB of
space based on my experience:

Provisioning – This one is
obvious, right? But you would be surprised how many people have
immature processes and procedures around disk provisioning. How many
people still manage their disks based on spreadsheets and command-line
scripts making the process time consuming and error prone.

Backup/recovery
– So you have to make sure that your data is protected, and that you
can get it back should the need arise. This can be a time consuming
effort, and one place that you can look for efficiencies that will save
you money. It's also a place that people sometimes forget to account
for when they are buying more disks. Don't forget that as you add disk
capacity, you also have to add backup/restore capacity, and that means
more tape, or backup disk, etc but it also means that you have to
account for the increased load on your backup admins as well.

Disaster recovery – All of the same things I talked about above with backup/recovery also applies to DR.

Data
migration – Sooner or later you're going to have to move this data
around. Whether it's because the lease is up on an array, or you need
to re-tier the data doesn't matter, what matters is that this can be a
costly process in perms of people time, and sooner or later you're
going to have to do it.

Performance management – At some
point you always get that call "hey, our database is slow and we've
looked at everything else and haven't found the problem, can you look
and see if it's the disks?" Unless you have some very mature
performance management processes in place, this tends to turn into a
huge people time sink.

Capacity management – We all know
that our data is growing, that's a given, so that means that we need to
spend some time planning how we are going to address that growth. When
are we going to have to make those new disk purchases, when will we
have to buy a whole new array? What about the switches? Are we going to
need to expand that environment when we bring in that new array as well?

Documentation
– yes, that's right, I said it, documentation is an important part of
managing your storage, and it can take up quite a bit of the storage
admins time, but it has to be done.
So the question I
always ask is, "how mature and efficient are your processes?" Do you
have a high degree of automation around all of the above? What use are
you making of technology to help you manage the processes above? If you
have very mature processes, employ a high degree of automation, and
make good use of technology to help you automate as many of those
processes as possible, then you probably have done everything you can
to drive down the cost of managing your storage. But now is a good time
to take a look and see if you can improve any of those areas. For
example, does my disk vendor really provide tools to make managing my
disk arrays easier? Not just from a provisioning standpoint, but from
the standpoint of all of the above. If not, maybe it's time to consider
looking at another vendor, one that has better tools.
Let me
leave you with a final thought in this area based on my experience.
What I found when I was managing storage was that the cost of managing
a TB of disk could easily meet or exceed the cost of buying that disk
over the 3-4 year life of that disk. So, a myopic focus on who has the
cheapest disks on a per GB basis may not make much sense. Perhaps what
we should focus on is how much it costs to manage a TB of a particular
vendor's disk. In other words, the 3-4 year TCO for any storage
acquisition needs to include the cost of management, not just the per
GB cost of the space.
SSD vs. Wide Striping

So,
what's this got to do with the topic at hand? Well, I think that a lot
of the argument around this is really an argument around the cost of
managing disks. Both technologies have their places, and both can help
you address certain performance issues, and both can help you save
money. The difference is that SSDs only help with a very small
percentage of cases, whereas wide striping can help you with the vast
majority of cases. What's more, wide striping can help you address
those management costs and drive down that 3-4 year TCO I keep talking
about, where-as SSDs really don't help there at all, and in a lot of
cases, I believe that the 3-4 year TCO goes way up with SSDs. That's
not to say that for those cases where you need the performance, that
using SSDs in a targeted way isn't a good idea. But just keep in mind
what I said about the cost of managing a TB of storage perhaps
exceeding the cost of purchasing it in the first place. In the end, I
think we need both, but I think that the bulk of your storage should be
on a side striped array where your storage admins don't have to spend a
lot of time trying to figure out exactly where they should place the
data so that the new LUNs will perform, and the added load doesn't
negatively impact existing applications.
My vision

So,
ideally, I think that the storage team should have a vast majority of
their data on an array that does wide striping, manage that space
though some kind of virtualization engine, and purchase SSDs very
tactically to address specific performance issues, again managing
everything through the virtualization engine thus allowing re-tiering
of the data should that be necessary, and making migrations when they
are needed quicker, easier, and less impactful to the business. You
also need to deploy software to help you with performance management as
well as capacity management, and something to help automate the
documentation process. This means that there is very likely not a
single vendor that can provide all of the technology, but rather you
will need to put together a "best of breed" approach you your storage
environment. Here's an example of one set of technologies that I think
can help get you to where you want to be.
IBM XIV storage –
The XIV provides wide striped storage on SATA disks and makes it all
very easy to manage. This is where I would put the bulk of my data
since my admins wouldn't have to sit there and try and figure out where
to place the data, etc.
EMC CLARiion – Put some flash
drives in a CLARiiON and I think you have a great platform for those
few LUNs you need that require the kind of performance that SSDs offer
if you have that kind of need.
Datacore SANSymphony - A
software approach to SAN virtualization which allows you to move data
around to different arrays without the users being aware that it's
going on. This is the way that you address things like re-tiering of
your data as well.
Akorri – This is a software tool that
helps you to manage your entire storage infrastructure find the
bottlenecks, and generally free up storage admin time.
Quantum
DXi 7500 – This is a deduplicating VTL that will help you reduce the
amount of time that your backup admins spend troubleshooting failed
backups.
Aptare Storage Console – This is software that will
help you manage your backups. It will report on things like what
backups failed, which of those were on SOX systems, etc.

The
above are just a few examples of what's available out there to help you
to create a more mature, automated, easier to manage storage
environment, but they certainly aren't the only ones, just some good
examples of what's available, and why you should be looking at that
kind of technology. In the end, whatever you choose, just making sure
that you are truly addressing the 3-4 year TCO of your environment is
the key to getting those management costs under control and allowing
your storage/backup admins to manage larger and larger environments.
               
               
               
               
               

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