IBM steps into home media servers

IBM HAS A big stand at CeBIT, and it is usually about as exciting as watching paint dry. While people talking about enterprise software for obscure verticals may excite some, we much preferred the hardware.

Dual Nehalems, single blade

IBM had two cool things to show off, blades and a home NAS server. The blades are nothing unexpected, but the company did a great packaging job. The Bladecenter HS12 is a single socket Nehalem, the HS22 is dual sockets. To pack two of those chips, 2HDs and six DIMMs per socket in a blade is quite a packaging job.

180 drive bays, enough for the average home

As you can see from the front of the IBM XIV storage server, it is a home oriented NAS with 180 bays in front. Each set of 12 is actually a quad Xeon server acting as a storage controller. Filled with 180 1TB drives, you get 80TB of storage. Yes, I did not forget the 1, you get a little under half of the storage, the rest is used for redundancy and speed.

XIV does not use RAID, it has it's own distribution algorithm that writes sectors to multiple drives simultaneously while spreading the write out across many drives. If you think about it, the RAID controller is often the bottleneck in many transactions, if you have ever noticed how a RAID5/6 array may take literally days to rebuild, you understand the problem.

Storage controllers and bandwidth are not scaling with drive capacity, so the time it takes to fill a drive grows with capacity. In the enterprise, this is deadly, and the size of SAS drives reflects this, speed is the key, not size.

To combat this, XIV scales IO as well as drive capacity, and they promise a sub-30 minute rebuild of any failed drive. That is amazing speed if you think about it, especially under full load. A lot of this speed comes from redundancy and the ability to spread out loads.

Back of the beast

To scale bandwidth like that, you need lots of I/O, and there are two rack mounted 24 port iSCSI switches in the middle of the unit, everything is fully redundant. To talk to the outside world, the switch on the right side has 24 fiber channel ports and 6 iSCSIs. It is pretty close to enough.

The software is also fairly simple, you just tell it you want a new pool, name it, section it into volumes, and attach it to an external port. It takes about 30 seconds total if you are slow, most of the tedious stuff is automated.

Volumes do not affect performance, you can make as many or as few as you want. Snapshots are automated as well, and can be manually scripted if you are into that kind of pain. You tell it what you want, and it semi-automagically happens.

In the end, just slap a wireless router on top, we would recommend an 802.11n with QoS capabilities, and you have the perfect home storage unit. You can carve off 20TB or so for every person in the house, and all stream your music without stepping on each other's toes. While it does not support DRM, it should be enough to back up many brands of small and mid-sized home media PCs. µ