Nexsan: The Nexsan array we looked at (it is actually housed in the same chassis as the Nimble array, so the look and configuration are quite simple – though there is a really large part missing, CASL, which I’ll get to in post 3). It’s a Hybrid array (meaning it leverages standard spindle disks and SSDs as cache). This is very similar to Tegile except there is user defined RAID levels (only 5 and 6), and it’s quite accommodating. You can choose how many SSDs you want as cache and you can choose how many standard disks you want.
The good: It’s extremely flexible. Multi-protocol (CIFS, NFS, iSCSI, FC).
The bad: The caching seems extremely similar to the Tegile. Data is cached as it is read or written – this provides for fast reads and write at the expense of the lifetime of the SSD. Because it’s user accommodating, I would think that most people would elect for standard MLC SSDs rather than eMLC SSDs and they will most likely run in to problems because of that (especially in write intensive environments). No compression or deduplication to speak of.
Dell (Compellent): We looked at upgrading our controllers. This provided us a way to keep our existing disks and infrastructure, only with newer controllers.
The good: We wouldn’t have had to rip out the entire infrastructure.
The bad: Price. The price is a massive con. It’s so massive that just the price of the controllers was 3/4 of the way to an all new SAN. No SSD Caching to speak of. Tiered storage uses tons of I/O for reads and writes for data progression. Licensing costs. Power usage is off the hook (right now our old Compellent array is estimated to be using between 2500 – 3000 watts per hour. That’s 2x Controllers at 500 watts a piece and 3x disk enclosures at 500 watts a piece, and this is literally not a joke, we monitor our power usage). Disk failures are rampant due the drives being thrashed for data reads and writes.
Nimbus Data: Nimbus is a full out all Flash based storage built on SSDs. It’s insanely fast.
The good: Crazy high I/O.
The bad: Price is totally out of range and this is absolute overkill for what we need. We are pushing about 3500 – 5000 bursted IOPs. The Nimbus array is pushing 1 million IOPS. I will say this as well – I tend to despise companies that hire the really gorgeous girls to sell you products (who really don’t know jack), and this is exactly what Nimbus does. I know this blog is called Dorkfolio and that I am a bit of a nerd, but just because I am a nerd and some gorgeous girl tries to sell me something doesn’t mean I’ll buy it. Nimbus employs some the most attractive girls I’ve ever seen at a SAN booth, and it’s all to lure in the nerds. I buy the product based on whether the product sells itself to me, not based on whether you have an extremely attractive girl trying to sell it to me.
We though about building our SAN based on Nexenta: Nexenta is a SAN OS built on Solaris for ZFS. It’s a pretty robust SAN solution. It takes a bit of work to set up, but once it’s set up, it would work… or I thought it would.
The good: We could build it for a lot cheaper than we could buy it from a SAN vendor for. RAID-Z.
The bad: No support other than the person who designed and built it. Reporting is sketchy at best (IE, if a drive fails, you’re not going to know about it immediately). SSD Cache is used as a fast spindle disk (once again, like Tegile). ZFS is 95% stable. In a production environment, 95% is not good enough.