May 03, 2007

Another External RAID Device

After the Maxtor OneTouch RAID became flakey last fall, we moved to a non-RAID solution for Fire's WinXP machine and moved the Maxtor RAID to my g5 OSX box because it seemed to work 'better' on my machine. She got an iomega 2x300GB external firewire enclosure. It is still working, but no RAID. The Maxtor finally got too flakey for me to stomach in March and I started poking around in April for a new device. I like RAID, conceptually, but have had a lot of trouble with it over the years.

Recently, a RAID-5 setup on erowid's main server has cost me dozens if not a hundred hours in the last two months. GAH! RAID-1 setups are less trouble, but still, good lord have I wasted money and time on them.

On the recommendation of KC, a friend in a local community, I purchased a FWBU2SATA35DMR FireWire 800 1394b & USB 2.0 RAID 0,1,JBOD dual drive SATA Enclosure from For simplicity, I'll call this generic box a FWBU2. It was about $200 for the bare enclosure. If it works, that's a fine price. Data Is Life.

I had several SATA drives sitting around and put two 500gb drives in this device and started testing the RAID-1 setup. I always try failing out a raid when I get it to see how it will handle badness, since that is the whole point of bothering. I was less than perfectly pleased with the FWBU2. Although tests showed that the data was on both drives, it did not really recover gracefully from the problems I threw at it.

KC said that he was not 100% pleased with the fan noise and also said he was having trouble with large file copies:

> So I mentioned I was having copy issues with it; turns out that if I try to
> copy a large number (>30gigs) of files to it, it disconnects. However if I
> tarball the parent folder, I can copy over pretty substantial archives
> without issue...go figure.

I have not had the problem he describe above, I've been dragging large file sets and dropping them onto it (two drives as one in RAID-1). I just finished a 15,000 file, 60gb copy and it went fine. I had previously done some other similarly huge copies without any trouble. I get 19-24.2MB/sec once it is going between my firewire drives and this thing on fw800.

However, on the less positive side, I have been very unimpressed by this device's handling of failure states.

1) It definitely does NOT like hot swapping. So far, both times I tried that, I ended up having to start from scratch. Not a show-stopper, but worth knowing.

2) It seems to never recover from having one of the drives get bonked. Make a RAID-1 with just a tiny amount of data. Yank a drive, write something onto it using another device, then put it back in. I tried several different methods and waited for it to "rebuild" (blinky red and blank and green and orange are the cues for this), left it for 12 hours and no luck. In a couple of tests, it just quit trying (the lights stopped blinking and the bonked drive just went solid red).

It actually took some fiddling to get the drives back to being happy at RAID-1 with a fresh partitioning. I had to set the enclosure to no-raid, format/partition each drive TWICE, then switch it to RAID, then partition again. Seems like whatever signature it is writing to the drives is both sticky and fragile in some way that I don't really understand.

So far, I have not found any low-end solution for external RAIDs that have made me very happy. I am leaning towards thinking that RAID-1 is just something that causes more trouble than its worth and, instead, having a 4x daily rsync of the entire drive onto another drive may be just as or more functional, without the headache of trying to use funky proprietary hardware.

As far as the fan noise goes on the FWBU2, the one I'm running here is pretty quiet. The fan NEVER stops, even when the drives power down, so that is very lame. I did some temp testing and I think I could safely just yank the fan entirely, I'll let you know if I try that.

I'm going to look into what inline fan controllers might be out there, there should be a trivial mechanical fan controller. Looks like these might be called "thermistors". I've purchased fans before with these built onto the fan or on a probe hanging off the fan. There are also inline speed controllers (voltage controllers) that I see. I have not yet opened the back of the unit to get a look at how the fan is wired, but my first thought is just to yank the fan entirely. The metal of the case should do a decent job of letting the heat out and my use for this is just for backups, not something I'll be running constantly.

It is lame that the fan doesn't stop when the drives are cool.

anyway, that's my current experience with this box. The last box I was using, a maxtor unit, was too flakey to use.

Posted by Earth at 05:11 AM | Comments (0)