Home RAID is now quite common. Folks are leaving their large arrays of disks on a server 24×7 for family viewing in other rooms and to simultaneously collect their ever growing library via some bittorrent client that really needs to be running always.

And, now, other than the needlessly paranoid datacenter cooling and extreme UPS, they have duplicated the environment where the OTHER model of the drive is probably the better choice.

This 1T Hitachi drive is available in the vanilla Deskstar model, in a “video model” that probably is not really needed if you are also using some of the raid versions, and most important this one is also in their Ultrastar version.

The controlled CRASH that the heads do every time you power down are just bad for long disk life. If you run the drive forever, and are in RAID where you quickly handle a read error with a few retrys and then simply give up and report it to the controller because it has other ways to still get the data you are behaving in the optimum way for a corporate RAID drive and the new class of always on home video raid server.

Hitachi, for this nicer environment, publishes specs for the drive that are better or simply not even mentioned for that Deskstar class drive. This Ultrastar 1T drive gets a 5 year warantee, and a listed MTBF of 1,200,000 power on hours (that is 136 years folks!).

Additionally, this class of drive typically is aware that it may be near other raid array members all trying to vibration issues from adjacent drives.

So what do they do differently? It is the microcode they loas it with. Hitachi has software you can download (you need to sign up for the his specialised program, but anyone can get it) that lets you go in and tweek and tune the drives behavior so that it is best suited for your needs.

The only site where I saw both the Ultrastar and the Deskstar listed together was in Europe, and the price was the same. Not sure what willhappne over here in the US once the obscene current price gouging settles down.

Folks like Seagate also have the same drive available in similar versions, and their end user single drive model may end in AS whereas the corporate RAID version of otherwise the same number willend in NS. Seagate takes the opportunity to stick it to the business user and charges a lot more for the NS drive.

There are now 2.5″ drives with MTBFs or 1,400,000 hours, with 10K rpm and SAS interfaces. This could be put in a laptop, but it probably lacks power down battery saving modes and maybe paranoid shock mitigating emergency head park strategies that are wise for a laptop.

I have been replacing crashed 2.5″ drives on high end Juniper routers, and am amazed at the folks selling these drives that simply do not read the specs and ask questions and have no idea which drives are best where.

Hitachi even has automotive ones that are rated for operation up to 85C because they may get there in a hot car and won’t have cooled before being started up and driven away.

This points to an 8 page compact PDF listing of the different current Hitachi drives and is well worth looking at:

http://www.hitachigst.com/tech/techlib.nsf/techdocs/9E4E119077AD1D8B86256DD0005A2F74/file/LineCard2(HU).pdf