Entries in macpro (1)

Thursday
Jun132013

Mac Pro 2013 Storage

There’s been a lot of talk about the new Mac Pro just announced at WWDC 2013 and I’m really liking what I see even if I have no real use for anything with that kind of horsepower.

But as usual, when Apple giveth, Apple taketh away. One big thing that’s currently missing from the newest iteration of the Mac Pro is internal storage expansion. Much noise has been made about the simplest types of solutions involving direct Thunderbolt connections to external drives (individually or multiple drive cases) and the resulting problems concerning cable mess, noise issues and the like.

I’m curious to see if Apple is going to be launching the Mac Pro with a suite of associated Thunderbolt peripherals since there is currently a dearth of products in this space since a super quiet complementary multi-disk storage system seems to be an obvious product. But in the meantime, we still have to cope with things like the fact that Thunderbolt over copper is limited to about 3m which can be problematic if you want (potentially noisy) expandable storage that’s not right beside you.

But even before the machine is released, we can imagine some useful and powerful solutions to these issues. In the enterprise world we do any awful lot with high-end NAS and SAN boxes but there are ways to profit from these technologies in a reasonable budget. Well, reasonable to someone ready to drop a few grand on a Mac Pro or two…

In any case, those of us with Mac Minis have already gone through this process of outgrowing storage that is handled by individual drives, and are often in spots that are inconvenient for hooking up external storage like home media servers.

So how to get there from here? The idea is to build an external storage box and using connectivity options that permit you to place it away from the office space where spinning disks and fans disturb the ambiance without penalizing performance. I’ve been using this approach for quite some time now but contenting with standard Gigabit Ethernet since my needs are limited to video and music streaming, plus some basic virtual machines for testing.

The big news that has surprised me is the appearance (finally) of 10GBase-T copper cards and switches. Yes, that’s 10GbE so more than plenty fast enough to handle most anything that a set of SATA drives can spit out like what we see in the last generation of Mac Pros.

Sticking with standard Ethernet CAT6 we can maintain 10GBase-T over a 55 meter cable. So we can easily put our storage a fair distance away from the office.

In order to use a standard PCIe expansion card we need a means of plugging it in. For this we have options like the Sonnet Echo Express SE which is a box with an 8x PCIe slot that you connect via Thunderbolt to the Mac Pro (or any Thunderbolt equipped machine for that matter).

There are a number of different 10GBase-T cards out there and one thing that remains to be determined is the driver availability for OS X. Sonnet proposes the Myricom Myri 10-G, but they don’t currently offer a 10GBase-T version. They are available with SFP+ Fiber (expensive) and CX4 (short cables). I did find a few cards available on Amazon like the Intel X540T1 at $353 or the HP G2 Dual Port card at $300 so there are options out there and I’m hoping that someone with deeper pockets than me will test the waters here.

I have a soft spot for using ZFS as my preferred storage technology for a number of reasons, including reliability and flexibility, but any number of server solutions are possible as long as they can publish a protocol OS X can talk to. With a build your own approach, you can find all sorts of boxes optimized for small, medium and massive storage options.

If your needs are relatively small, you could go the route of something like the HP N40L Microserver. Currently my setup with these machines are capable of saturating a standard GbE link (sequential IO) with 4 low RPM SATA drives, so there’s some headroom left going to 10GbE with speedier disks or even SSD.

Accessing the storage server

I prefer using NFS (but am waiting with great interest to see what 10.9’s SMB2 implementation will bring) for sticking with a NAS protocol approach, but if you prefer working with storage that is seen as disks by the OS, you can use iSCSI if you’re sticking with ethernet and TCP/IP as the transport. Fortunately, the GlobalSAN iSCSI Initiator will do the trick.

If you are dedicating the storage to a single machine, you can simply connect everything directly, but this kind of setup can be shared, but you’ll need a switch. Currently the best deal that I’ve seen out there for reasonably priced 10GbE switches is the Netgear 8 port 10GBase-T switch (~$900).

It’s true that all of this is considerably more complicated that simply popping off the side of the machine and connecting a new disk, or buying a little Thunderbolt external array, but if you need serious performance and serious capacity, even the old Mac Pro would reach some limits pretty quickly. Moving to a dedicated storage system permits better performance, sharing across multiple machines and many more options for growing the system over time.

I suspect that the majority of folks doing massive video work are already using some kind of SAN, whether Fibre Channel or iSCSI so the impact to them is mostly buying the Sonnet expansion box. It’s all the people in the middle who are currently making do with 3-4 disks who have to start asking a lot of questions about how to plan for storage management.