[AusNOG] 10gbit iSCSI SAN's which support active sync across multiply enclosures

[Scott Arentz]

Hi James

I've been playing in the storage space for a number of years, and if there is one thing that I have learned, it's that whatever solution you adopt, it must suit all your needs.

12 months ago, we went through a similar exercise, and starting with a clean slate, I looked at all the options available and met with vendors, techs, sales people etc.
Our requirements were speed (large SQL DB's and a web app that needed to write,read,move,delete almost a million small files an hour from multiple hosts), redundancy (disk, PSU, controller, multi path, etc) and of course value.

We also looked at both iscsi and fibre channel.

Some vendors were knocked out quickly due to their lack of product knowledge (an unnamed, single syllable  vendor of budget servers, pc's and storage had to ask me what a SAN was)

We looked at the LH series, but found that in order to get the level of redundancy we needed, we would need 2 of them. HP, at the time, were also just about to launch their new SAS units, so they were only quoting on the older SCSI units.

NETAPP also pushed hard for the business, but on closer inspection of their offerings, we found them more suited to tier 2/3. Once again, full redundancy would have required multiple units.

The one vendor we didn't consider originally was hitachi (HDS), simply because they are known to be pricey. I've work with HDS kit for years and found it very reliable, but not cheap.

In the end, we did invite HDS to quote and were very surprised by what we got.
The AMS2000 series was perfect for our needs.
4RU, dual PSU, dual controllers, 15 drive bays and support for additional solid state
Fully expandable by adding additional shelves and with the ability to use a mix of SAS and SATA in the one shelf
Truecopy (replication) ready for us when we want it

We went for fibre channel (8gig) rather than iscsi simply due to cost. A pair of 24port 10Gig switches was almost 10x what the same in FC switches cost us. We can use 1Gig iscsi as well as FC
FC HBA's were also considerably cheaper and I didn't have to worry about the complexity of configuring Ethernet failover.

What we ended up with was a complete system where only the chassis was a single point of failure. Given that these chassis are simply a case with a couple of switches and lights, there's not much to go wrong.
HDS engineer's installed and did the initial config for us.
One of the services that I feel sets HDS above the rest, is there commitment to their product.
You are assigned a hitachi engineer to look after you
HDS monitor the hardware for you
At least once a year they come onsite and perform microcode updates and health checks (all without an outage)

They offer multiple levels of support from NBD to 24/7

EMC offered the same features, but fell short on the quotes.

My thoughts on any IT related hardware purchasing, is to favour those vendors whose core business is in the hardware you want. For servers, pick a vendor who excels in servers, for storage, pick a vendor who invests heavily in their own product and doesn't simply rebadge someone else's or who has so many irons in the fire, they can't provide good support on any single product.

This way, you get the best support possible from the initial call, to the final solution.

In summary,
HDS and EMC would be my first choice. Both are storage vendors with excellent reputations.
HP are good, but not their own kit. Be wary of the final price. A fully spec'd system to your needs could be a lot more than the initial quotes.
Netapp would be a perfect solution if large capacity,efficient storage is your goal. You sacrifice speed for  capacity however
DELL, not sure whose kit they're using these days. It used to be low end EMC, but I think that's changed.

Anyway, that's my two cents based on my own experience

Regards

Scott





-----Original Message-----
From: ausnog-bounces at lists.ausnog.net [mailto:ausnog-bounces at lists.ausnog.net] On Behalf Of James Andrewartha
Sent: Sunday, 13 May 2012 10:57 PM
To: Adam Nock
Cc: ausnog at ausnog.net
Subject: Re: [AusNOG] 10gbit iSCSI SAN's which support active sync across multiply enclosures

On Sun, 13 May 2012, Adam Nock wrote:

> Quickly looked at their website, i THINK it was the MetroCluster system, but i might be wrong.
> 
> I remember liking that all their gear (bar the poor little SAN at the bottom of the heap) supported all the features they had on offer (via feature licensing of course).
> It might mean you can get the small size you want with good DR potential.

Being an admin of a MetroCluster, it does do what it says on the tin, but doesn't meet this requirement:

> I’m looking only for a 2RU to 3RU unit with about 4tb to 10tb of RAID 10 SAS storage.

The controller alone will be 3RU, plus another 2RU for the disk minimum, and ideally you'd have two shelves. We also evaluated IBM V7000 which has a remote mirroring feature and has dual controllers and disks in 2RU. And as others have mentioned, EqualLogic, although we didn't look too close at that.

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