Another Boring "Which SAN" Thread: EMC, Hitachi, Compellent

[JDG1234]

I know everyone gets bored with the "which SAN' should we choose thread, but for those of us (Me) who have only worked with EMC in the last 10 years, we have to look to other users for feedback regarding the comparison between the 3 units.

We have finalized our SAN configurations and need to decide between an EMC VNX  5300, Hitachi AMS2100 and Compellent Series 40.

We will be utilizing FC for 95% of our host connectivity.  We are currently not virtualized, but willl be using VmWare to do so.  The vmware hosts will consist of SAP Production (about 200 users), QA, and Dev.    Exchange 2010  (300 users), standard file server and a few other small services such as internal Intranet web server etc.  Nothing that is over the top

Our basic storage configuration of the SAN units are:

32 - 300 GB 15k SAS drives

54-  600GB 15k SAS drives

9 - 2TB 7200RPM SAS drive

We have all of our pricing in, Hitachi is the lowest, EMC is in second and Compellent is the highest.  Obvioiusly, we have to choose the solution that will be the best fit for our environment.  Though pricing does play a role in our decision, it is not what we are primarily basing our decision on.   Any advice would be much appreciated!

[chriswahl]

I typically look at SAN features (dedup, disk grouping/config, maint cost) and supported VAAI primitives. Spinning disk is the easy part.

Here's a good list of what VAAI can offer: http://blog.fosketts.net/2011/11/10/complete-list-vmware-vaai-primitives/

At the end of the day, whichever frame you're comfortable with is the right choice. You have to maintain and support it after all.

[mcowger]

I agree with Chris. Look at features, not disks.  Look at integration, not disks   Look at management ease of use.

I will let you come to your own decision based on that advice.

Take a look at what other people on the forum have experience with all those arrays.  There was a recent thread on AMS, for example, that your shoudl check out.  Also check out VAAI support - theres only 1 array in that list with full VAAI support.  Ask your vendor to demonstrate creating a LUN and allocating it to your env.  Ask them to show you how to use pools.  Ask them to show you their VAAI support.  Ask them to show you their vCenter plugin and what it can do.

(disclaimer, I do work for EMC, but have used all of those arrays as a customer).

[mikearm]

I think buying a SAN is like buying a house, you may want a 3 bed but not all 3 beds are exactly the same, there are so many different aspects to consider and it's what fits for you.

If I was buying I would consider the following:

How many disk can you get under a datastore.

I worked with 2 Netapp clusters for 5 years and would never buy one again. The number of spindles available is limited in the aggregate, and yes you can get upto 2TB cache, but it's only read cache, if you have a write intensive workload it's pointless.

I then worked on a contract with a Compellent and was very impressed Effectively a datastore could be on any of the disks within the SAN. You may want to create a storage profile to keep your DB datastores on higher tiers, but it worked well.

What are the features that support VMware.

I agree with the other poster that VAAI and specifically ATS takes the headache out of the number of VM's per datastore, but the copy and clone stuff requires quite a strict criteria to work, scenarios that don't work:

• The source and destination VMFS volumes have different block sizes
• The source file type is RDM and the destination file type is non-RDM (regular file)
• The source VMDK type is eagerzeroedthick and the destination VMDK type is thin
• The source or destination VMDK is any sort of sparse or hosted format
• The logical address and/or transfer length in the requested  operation are not aligned to the minimum alignment required by the  storage device (all datastores created with the vSphere Client are  aligned automatically)
• The VMFS has multiple LUNs/extents and they are all on different arrays

The Compellent supports VAAI by the way.

Dedupe

Well it's great if it works but if you have to pay three times as much it's a false economy. i.e we are putting in a Netapp metro cluster at the moment, and out of 144TB we are getting 25TB usable. (using external disk) With dedupe of up to 70%, that gives us 42.5TB, if it works and has enough IOPs to complete the dedupe run every day. Alternatively we could have purchased a cheaper solution without dedupe and got the same amount of disk potentially (it was purchased before my contract started)

Snapshots

I would expect most arrays to do this, but they should be efficient on disk. The Compellent is quite cool as it migrates the unused part of the snapshots to slower disk, and doesn't store the snapshot in the same volume.

This provisioning

I woud hope all storage now supports this.

User interface

If you have a specialist storage team, it's great doing everything command line. But if you are a generalist the GUI is your friend. I found the Netapp was ok for provisioning but command line had to be used for granular information. The Compellent has a lot of information in the console, and if you get Enterprise manager it provides a lot of info.

For provisioning, creating snapshots, creating replication targets, tuning bandwidth usage etc etc, the Compellent I found easier and very rarely used the command line.

Support

The place where I worked with the Netapps, I forced us down the HP server path, as the Dell support we were receiving at the time was awful. To my surprise they have kept the Compellent support guys in the US, and they are good, and have remote dial in access (if you allow it) There is non of the scripted automons on the phone, the guys who answer the phone know their stuff.

Renewals

I got burned on this, when you need to replace your Netapp controllers you have to purchase all the software again, which is where most of the cost is. Whereas with the Compellent, you just buy the controller and the software licensing is ported across (please check if this is still the case, that is 5 month old data). The other point Compellent will support the hardware 5 years after it has gone end of life as long as you are still in support.

I also seem to remember that the support renewals for the Compellent are based on a equation rather than a salesmans commission.

I hope this all helps, if I bought a compellent I'd buy all 15k 450GB (600GB disk are at a premium) disks for tier one and then the 2TB SAS for tier 3.

I know I sound like a poster boy for Compellent but it's actually quite good, if your in the UK I can put you in contact with a reseller who may do open book , so you can see his purchase price, which might help you get the price down.

[mcowger]

"The Compellent supports VAAI by the way."

Not fully.  I believe they only support Block Zero, XCOPY and ATS, at the moment, not the other primitives.

[mcowger]

Its also worth mentioning that only 1 of those arrays can support NFS if you ever do decide to go down that route.

[JDG1234]

I definitely support any and all feedback coming.  Obviously, I am biased toward EMC as that is all I have worked with in 10 years, but I want to give the other vendors their fair shake.  From what I have seen, the Compellent appears to be a very good unit, however, with the Hitachi coming in at a little over 100k, the EMC coming in around 140k and the Compellent coming in at 160k , I woudl have to have a very compelling 60k argument to choose the compellent.

Thank you all (and any future posters) for your input.  It is greatly appreciated.

[chriswahl]

JDG1234 wrote:

I woudl have to have a very compelling 60k argument to choose the compellent.

Pun intended? :smileysilly:

[JDG1234]

Pun definitely intended 🙂    Figured, I would throw out an update.

The Compellent was overpriced and the Hitachi ended up what we felt to be as underpriced to the point where it felt as if something was missing regardless of the reassurance that it wasnt.  Though I have basic knowledge of storage and storage design, we had to rely heavily on the vendors to provide us with the correct solution.  So after reading many other reviews and discussing with the engineers at EMC, we chose a VNX5300

I must say that CDW/EMC did an excellent job of responding to our questions and were always more than willing to join conference calls. We have had the unit in for several months and have been very happy with the performance and stability.

[mcowger]

I'm glad we (EMC) were able to help you.

Do let me know if you have questions.