CrashLoopBackoff

After jumping in with a post last week on tierless caching I wanted to jump in with my thoughts on a second Tech Field Day vendor. Avere presented a very interesting and technical presentation. I appreciated being engaged on an engineering level and not a marketing pitch.

Avere tiers everything. It is essentially a scale out NAS solution (they called it a FXT Appliance) that can front end any existing NFS. Described to me by someone else as file acceleration. The Avere NAS stores data internally on a cluster of NAS units. The “paranoia meter” lets you set how often the mass storage device is updated. If you need more availability or speed you add Avere devices. If you need more disk space you add to your mass storage. In their benchmarking tests they basically used some drives connected to a CentOS machine running NFS front-ended by Avere’s NAS units. They were able to get the required IOPS at a fraction of the cost of NetApp or EMC.

The Avere Systems blog provides some good questions on Tiering.

The really good part of the presentation is how they write between the tiers. Everything is optimized for that particular type of media, SSD, SAS or SATA.
When I asked about NetApp’s statements about tiering (funny they were on the same day). Ron Bianchini responded, “that when you sell hammers, everything is a nail.” I believe him.

So how do we move past all the marketing speak to get down to the truth when it comes to Caching and Tiering. I am leaning toward thinking of any location where data lives for any period of time as a tier. I think a cache is a tier. Really fast cache for reads and writes is for sure a tier. Different kinds of disks are tiers. So I would say everyone has tiers. The value comes in when the storage vendor innovates and automates the movement and management of that data.

My questions/comments about Avere.

1. Slick technology. I would like to see it work in the enterprise over time. People might be scared because it is not one of the “big names”.
2. Having came from Spinnaker. Is the plan to go long term with Avere, or build something to be purchased by a big guy?
3. I would like to see how the methods used by the Avere FXT appliance can be applied to block storage. Plenty of slow inexpensive iSCSI products that would benefit from a device like this on the front end.

The first place hosting the delegates was NetApp. I basically have worked with several different storage vendors but I must admit I have never experienced NetApp in any way before. Except for Storage vMotioning Virtual Machines from an old NetApp (I don’t even know the model) to a new SAN.

Among the 4 hours of slide shows I learned a ton. One great topic is Storage Caching vs Tiering. Some of the delegates have already blogged about the sessions here and here.

So I am going to give my super quick summary of Caching as I understood it from the NetApp session. Followed by a post about Tiering as I learned from one of our subsequent sessions from Avere.

1. Caching is superior to Tiering because Tiering requires too much management.
2. Caching outperforms tiering.
3. Tiering drives cost up.

The NetApp method is to use really quick Flash Memory to speed up the performance of the SAN. Their software attempts to predict what data will be read and keep that data available in the cache. This “front-ends” a giant pool of SATA drives. The cache cards provide the performance the the SATA drives provide a single large pool to manage. With a simplified management model and using just one type of big disk the cost is driven down.

My Take Away in Tierless-Caching

This is a solution that has a place and would work well for many situations. This is not the only solution. All in all the presentation was very good. The comparisons against tiering were really setup against a “straw-man”. A multi-device tiered solution requiring manual management off all the different storage tiers is of course a really hard solution. It could cost more to obtain and could be more expensive to manage. I asked about fully virtual automated tiering solutions. Solutions that manage your “tiers” as one big pool. These solutions would seem to solve the problem of managing tiers of disks, keeping the cost down. The question was somewhat deflected because these solutions will move data on a schedule. “How can I know when to move my data up to the top tier?” was the question posed by NetApp. Of course this is not exactly how a fully-automated tiering SAN works, but is a valid concern.

My Questions for the Smartguys:

1. How can the NetApp caching software choices be better/worse than software that makes tiering decisions from companies that have done this for several years?
2. If tiering is so bad, why does Compellent’s stock continue to rise in anticipation of an acquisition from someone big?
3. Would I really want to pay NetApp sized money to send my backups to a NetApp pool of SATA disks? Would I be better off with a more affordable SATA solution for Backup to Disk even if I have to spend slightly more time managing the device?