Take the 2-minute tour ×
Super User is a question and answer site for computer enthusiasts and power users. It's 100% free, no registration required.

I'm in the (long, drawn-out) process of re-starting (and updating) my backup procedure. This time around, I'm adding a pair of external eSATA hard drives that will cycle to an off-site location. Reasoning that while these drives are off-site and unattended they're more vulnerable, I'm encrypting them using TrueCrypt.

However, I've noticed something odd. The filesystem on my TrueCrypt volume is ext4, which of course has the top-level lost+found directory. But I've noticed that after it has been mounted for a while (we're talking days here, I've been too busy to stay focused on this task for any real stretch at a time) the lost+found directory disappears. I can still apparently write to it (touch foo created a file, no errors, although I deleted it before thinking to try unmounting/remounting it to see if it stuck around), and so far SMART hasn't found anything wrong with the physical drive (it's currently unmounted and running an offline test via smartctl -t offline /dev/sdf, which has another 5-ish hours to go).

My question is, does TrueCrypt automatically unmount an encrypted volume after it's been idle for a certain amount of time? If so, can I override that behavior? If not, what else can explain what I'm seeing? What would I look for in the logs (which are flooded with spam from cron and dhclient, the latter I really need to kill because the server has a static IP, so I haven't been able to spot anything even remotely relevant)?

FWIW, I mounted it with truecrypt /dev/sdf1 /mnt/esata, and I've unmounted it with truecrypt -d (it's the only TrueCrypt volume). I'm using the latest TrueCrypt 7.0a 64-bit console-only, downloaded straight from their website. This is running on an Ubuntu 10.10 server. The process to create the TrueCrypt volume was (roughly) 1) Create an empty partition, 2) truecrypt -c /dev/sdf1 and then follow the on-screen prompts (reasonable password, no keyfile, no hidden volume, format with ext4). Sorry I can't be more exact on this bit, but it was about 2 weeks ago and I have the memory of a goldfish.

share|improve this question

3 Answers 3

Perhaps power management is kicking in automatically? Is there any automatic power management in the BIOS?

share|improve this answer
    
Hm, good thought. I'll investigate that, although unfortunately that will have to wait until this weekend when I can physically get to the box again (currently traveling). –  Kromey Apr 22 '11 at 0:18
1  
I've encountered a few IDE hard drives over the years that shut themselves down too. If the BIOS doesn't pan out, try setting up a cron job that accesses the drive periodically. Have a nice trip! –  Randolf Richardson Apr 22 '11 at 0:27
    
@Randolf Ooh, that's a really good idea, too. And these are WD Green drives, so that could very well be the reason! I wonder though (if this is indeed the case) if there's a way to let it power down until I actually need it again (short of creating a mount-backup-unmount process, that is)... –  Kromey Apr 22 '11 at 0:40

Do you ever use the GUI?

There are preference settings for auto-dismount. You can see them in this screenshot on the TrueCrypt website.

I don't know for sure though if the GUI preferences have any impact on the CLI usage.

share|improve this answer
    
Unfortunately, it's a server installation with no GUI at all. I suppose I could put a GUI on there, but, again, it's a server -- it's not supposed to have one. –  Kromey Apr 22 '11 at 0:17
up vote 0 down vote accepted

BIOS didn't have any power-saving features turned on, and I couldn't find any that were enabled in my Ubuntu server system either (well, except for turning off the monitor after so much inactivity, of course). I never actually did find a direct answer to this question, but it's bugging me to accept an answer here, so here's what I did to address the situation:

I've scripted the process of mounting & decrypting the hard drive, running the backup routine, and then promptly unmounting the drive again. As a convenient side-effect, it makes it easier to grab the drive and remove it for taking it to off-site storage.

share|improve this answer

Your Answer

 
discard

By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.