Possible : USB in RAID?

[Dennis Brouwer]

Hi all,

I want to build a new fileserver based on FreeNAS. The system is a Small Form Factor PC with 2 S-ATA ports.
I like to add 3 other disks through USB. But if i connect them through USB, will i be able to put them in the(or a) RAID array?

I hope someone can help me out with this question!

Thanks in advance.

DennusB

 

[jgreco]

It should work but it isn't necessarily a great idea, since the USB drives will probably have an independent power supply and cabling. Let's say you have five disks in a RAIDZ (RAIDZ1) configuration. You then accidentally yank a USB cable, suddenly your data loses redundancy and the pool has to be resilvered. If you accidentally lose more than one cable, you might do so much damage as to lose the pool.

My suggestion? There's probably nothing wrong with using external storage, but if you want to protect that data, you are probably safest mirroring two identical external drives in RAID1.

 

[cyberjock]

I agree with jgreco. Going USB for your hard drives isn't exactly the most reliable way to handle your data. It's kind of risky with all of those individual cables and such to accidentally unplug a few key cables and watch your pool disappear. If you were going to use the configuration just to see how it works and get comfortable with it while storing no data of any value I'd say go for it. But as a production machine I wouldn't do it.

 

[StephenFry]

I know a sysadmin who got fired for building a USB-RAID system for the company he worked for, instead of a proper setup.

But that aside, yes it's possible, but it's a bad idea. Speeds will be slow unless you use USB 3.0 and apart from jgreco's concerns, I've never encountered a good quality controller in external drives, so during heavy usage they're likely to start barfing.

eSATA however, would be a decent alternative.