Topic: External Harddrives; Connect or Disconnect?

[stevetoney]

I once read some advice (not sure if it was from an expert or not though) that since external drives are indeed external, they aren't really built to be connected full time and spinning whenever your computer is on.  However, in a resurrection attempt, I recently hacked into the case of a failed external WD drive that I have and discovered that it is nothing more than an internal drive housed inside its own plastic case that allows it to be connected via USB2.0.  This discovery leads me to conclude that there's really no difference between the drives that are internal to most machines and the drives that are inside an external drive...so the logic posed in the first sentence doesn't necessarily make sense to me anymore.

So, drive experts out there, please shed some light. 

Obviously, an internal drive is on and spinning whenever the computer is on, so it's logical to conclude that it's not inherently bad for a drive to be on all the time.  Since external drives seem to be cut from the same cloth, it would seem that it may not be bad for external drives to be on for long periods of time either.

However, for data backup purposes in which I only am using a drive for data backup (don't need to access the data unless there's a drive failure) and don't need to backup more than say once a week or every other week, should I be leaving my external drives connected and live while my machine is on or should I disconnect them and only use them when I need to backup some data and then turn them off again?

At what point might it be better (for drive longevity) to leave the drive running continuously vs. disconnecting?

[rastasean]

this is precisely the reason I don't like the external all-in-one enclosures: when the drive is connected to the computer, it is powered on and running regardless of your data being accessed. It may not run much and may have a low temperature but the only way to power the majority of them off is to disconnect it from your computer.

I think by the simple fact of having the drive off and disconnected it would last longer but hard drive makers may say it doesn't much matter since there may not be a statistical study done to prove if this is the case or not.

What you could do is take the internal drive out and get an external case with its own power supply and therefore control it being on/off AND connected to your computer.

[OFOTD]

If you are running a version of Windows (since XP) then the Power Management feature dictates if your external drive is spinning or not.    You may have your power settings set to 'never' turn off (spin down).

[it-goes-to-eleven]

For years now most external drives spin down when not in active use, which means they stop.  That's why there is often a delay when they are accessed.   Some poorly written applications may regularly access drives, causing them to stay spinning.

The spin down is necessary because the enclosures don't provide enough cooling to run the drives constantly..... and as for them being identical to internal drives... that is a bad assumption.   Drives of the same basic model often have different firmware depending on the intended use.  Spinning down your internal drives is also a good idea - most PCs do not provide sufficient cooling for drives, and it contributes to premature failure.  However, spinning the drive up and down constantly is also bad.

Drives can be spun up and down via software.  It isn't necessary to unplug them for that.

You never know when a power surge might occur, or some malware might trash the drive contents.   Of course that probably requires that you unplug both cables.  Drives left out in the open are also subject to theft.

[stevetoney]

So, based on your response, it seems as if you're suggesting that I can therefore assume that it's OK to leave my drives connected, thus essentially allowing my PC to manage their health?

[it-goes-to-eleven]

You should verify that they are spinning down...  I just opened a 1tb western digital external under xp and it took ten seconds to come up.  So it was spun down.  The enclosure was still just a bit warm, so you can't tell that way.

[SmokinJoe]

My opinion... drives are like car engines... the worst thing you can do to either is start it up, shut it down, start it up.  So any power management scheme which spins it up and down several times a day is bad.  In that case, let it spin 7x24.  But if you really aren't going to use it for 2 days, unmount it and throw the power switch, if only to save electricity.

[it-goes-to-eleven]

My opinion... drives are like car engines... the worst thing you can do to either is start it up, shut it down, start it up.

That's a good point...  I believed that in years past, but not so much anymore.  Especially not with poorly cooled (most) externals. Modern drives are much more sophisticated than in the past.  They compensate better for temp changes, have better bearings, etc.  I've had good luck leaving drives running, but there is also a point where it is a negative (especially if you live in a part of the country with thunderstorms). I'm sure there is a sweet spot that varies depending on the drive.

The number of spin-up cycles, temp, max temp, read errors, seek errors, etc, are tracked by the drive.  You can retrieve and monitor those stats values from the SMART system (smartmontools is one utility).  I like to keep my drives no hotter than 30C.  Above 40 is definitely hot, but many systems are that way.

Another gotcha with externals.. They are very vulnerable to bumps and knocks.  It isn't such a big deal if they aren't spinning. But when spun up, they're very fragile.  That's a verrry good reason to keep externals shut down.    I worry about dropping something on a table and having the bump bounce the heads on the platter.

[anr]

Interesting that you say WD drives.  My mate has just asked me to try to recover data from two of these which failed at the same time.  After trying just about every utility under the sun I, too, opened the cases.

One drive was marked "WD Scorpio" and the other "WD Branded".   The former had some rudimentary but probably quite effective EMC shielding; the latter had nothing at all.   I did manage to access one drive by swapping the SATA > USB converter card that provides the USB interface but the data was corrupt.   But the lesson learned was they used different drives and very different interface cards, one of which was of very poor build quality, on what was sold as the same USB External drive - there being no way to tell externally.   

[Scooter123]

A 2tb SATA is less than $175.  Spin away.  Who cares? 

This assumes you follow the 3-2-1 Rule.  3 copies of your data; 2 on site; 1 Offsite. 

[H₂O]

Physically the drives are the same and have gotten better over time.


(i.e. drives will spin down to conserve power when a machine idles (depending on the power settings and drive itself), etc - better shock handling esp with 2.5" drives)


I would keep the drives off line if they are your backup to protect against the following:
 - big surges (i.e. lightning, etc) - keep them unplugged from power when not in use
 - virus or some sort of data destroying trojan


Depends if this is device usage and what your budget is on what the best back up solution is - but I follow the above for personal low access use - I also take a copy of my important data on a drive with me on long trips - could keep copies at a friends house.