Prolonging hard drive lifespan by umounting...
 

I had a thought, instead of mirroring my drives with RAID would I be able to prolong the average lifespan of my drives by mounting the dedicated backup drive(s) only when performing a backup then umounting it when done (say nightly or even weekly)? Does anyone employ this tactic?

My understanding is that if the drive is mounted it is spinning and doing more work than it would be if it was not mounted. Is there any credence to the idea that such a strategy would prolong the life of the drive being used intermittently?

Background Info:
- home file server
- expected up time 24/7/365
- data doesn't change often
- data grows at a slow rate
- data is read often

I do this on my server, but only because my server is physically too small to have multiple 3.5 drives in it; so every day it backs up to a 2.5 laptop drive.

Just unmounting the drive won't necessarily put the drive into a low power mode though (unless you have one of the new drives that specifically does this), you would want to play around with hdparm settings so the drive goes to sleep after a certain amount of inactivity.

I don't know that this would increase the average lifetime of the drive, and I would be willing to bet that some would even argue the repeated on/off cycles will be harder on the drive over the long term than simply spinning at idle. In my case I did it for space and power consumption reasons, not to try and prolong the hardware; so I can't say the effect there (but it certainly saves energy).

Yes, thank you MS3FGX, hdparm does have the ability to turn down the operating level of the disk. BTW, according to hdparm my unmounted drives are still 'active/idle', which is the normal level of operation, and they don't seem to go into a low consumption mode on their own.

So in theory, I could indeed umount my drives, and put them to 'sleep' (low consumption mode), as long as I don't cycle them between these two modes too often (which would cause them to wear prematurely). From personal experience I know I won't need to cycle the drives more than once a week to do the backups. Does anyone see anything wrong with that? Once a week doesn't sound like too much does it?

I really wouldn't worry about spinning a disk up once a week for backups and leaving it spun down the rest of the week. That seems like a very easy life for a hard drive. My box is shutdown every night and I suspect many others are too, so once a week is nothing.

The disk cycling issue is a problem you can get with some drives that go to sleep far too quickly and get themselves into a sleep, wake, sleep, wake, sleep, wake... situation during normal system use.

By the way, going back to your original post, using raid-1 as a backup is not a good idea as it's not a true backup solution (it protects against hardware failure, but not data corruption or accidental deletion), so you're better off having a dedicated backup drive for other reasons than just disk wear.