Replacing disks and data loss?

[HNLRoscoe]

So I've screwed up in a number of ways,

I threw my FreeNAS setup together, without properly reading the documentation or knowing precisely what I was doing. Now I've got some problems and was wondering if some of you guys could help me get back on track.

I've got 7x 2TB drives set up in RAIDZ-2, and for a while I've been having some SMART issues with one. I've been getting CAM Status Timeout errors and have been unable to perform SMART tests on it, but it still seemed to be working, and I wasn't receiving major alerts, so I just let it go.

Now I'm showing a degraded status because another one of my drives is acting up. I realize I need to replace both of those disks, but the other way I screwed up is that I bought consumer grade drives instead of NAS drives, which according to this article http://www.custompcreview.com/artic...ard-drive-network-attached-storage-nas/19177/ are prone to disaster when you attempt disk replacement.

Long story short, my main question is, in the experience of you more advanced FreeNAS users, how liable am I to lose everything in my pool if I get some new NAS drives and attempt to replace them? If I've got about 3.5 TB of data in the pool right now, would it be a good idea to get a 4TB drive and back everything up to it before I attempt replacement? Following that, in the interests of making sure I never screw up this bad again, I think I need to learn how to set up automatic SMART tests and periodic email notifications. Instructions for that are in the wiki right?

P.S. I can provide exact error messages for the drive that's giving timeout and CAM STATUS errors, but still appears to be functioning if it would help.

 

[cyberjock]

That article is partly right and mostly wrong. I'm using WD Greens and had great success. To be honest, I wouldn't worry about having desktop drive as much as not replacing failed ones. If you're going to lose data its because you aren't replacing failed drives diligently. You gotta do that or you are sunk... and you aren't doing that.

SMART stuff is available in I have a how-to in the forums on what schedule I use. Up to you if you want to use my schedule or not.

So worry less about what disks you buy and more about replacing disks when they start failing.

 

[HNLRoscoe]

Ok thanks, Cyberjock. Really appreciate the quick reply.

I'll get on replacing both of those drives.

 

[diedrichg]

Raidz2 is doing its job. Your data is intact for the moment. If you lose more than 2 drives you will lose your data. Get them replaced asap and get a spare or two to keep on the shelf for future replacements so you won't have to wait for them to be delivered.

Also - note that your pool will only be as big as your smallest drive's capacity. Replacing a 1TB with a 4TB does not equal a 3TB gain across all drives unless all drives are 4TB, that 4TB drive will look like a 1TB drive.

 

[HNLRoscoe]

Potentially stupid question:

I'm looking at some NAS drives as replacements since they cost about the same as the consumer grade ones, and they all say they're for 1 to 5 bay systems. Since I'm using 7 bays in my NAS, should I bother getting one of the NAS drives or would it cause problems?

 

[cyberjock]

That stuff doesn't really matter. You're probably talking about the WD Reds. Many people here have more than 5 and it works fine. ;)

 

[HNLRoscoe]

Yeah, both the Reds and the Seagate NAS drives say 1-5. Since it doesn't matter, I'll order them up tomorrow. Thanks.

 

[Ericloewe]

The new Reds are now "rated" up to 8-bays.

Not that it realistically makes a difference, anyway. If it did, the Greens would be worse off ;).

 

[joeschmuck]

If you have two failed/failing drives, I hope you have started backing up your data to other drives/devices. Even if you scattered it around, at least you would have a backup copy should your pool reach an unfortunate ending. One thing you should post is the output of "smartctl -a /dev/ada0" (where ada0 represents your drive), and post the output for all your drives. IDs 5, 197, and 198 are the main ones to look at. We can then tell you how bad of a situation you are in. Also if you don't NEED access to your NAS, I'd recommend turning it off until your new drives are in hand.

 

[HNLRoscoe]

Ok, well I replaced the disk that's been giving me trouble since the beginning. Luckily I live near Newegg's distribution hub, so ordered the drives on Sunday and got them Monday afternoon. Took me a while though 12 hours for scrub and 15 to resliver, but it's done.

I caught a CAM error on the other drive that was giving me trouble, and saw it get dropped from the pool on my console, but now since I've rebooted, I'm not getting it anymore and here's what SMART tells me:

Code:

smartctl -a /dev/ada6
smartctl 6.1 2013-03-16 r3800 [FreeBSD 9.1-STABLE amd64] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org

/dev/ada6: Unable to detect device type
Please specify device type with the -d option.

Use smartctl -h to get a usage summary

I'm going to replace it now. Should I put the SMART reports for the rest of my disks in this one post, or have a separate one for each?