Keeping HDDs healthy (and not making them fail)

[dropko]

Dear all,

I have had my Pi (B) for about 6 months, and extremely happy so far with it.

Unfortunately, in that period I (?) have managed to "destroy" the HDDs I attach to the Pi. After a while, they begin with the "clicking sound of death", which I presume being caused by bad sectors in the disk. It has happened to both disks so far and now I don't want to buy another disk just to see it fail a couple of months later, and I don't think warranty would cover these.

I believe this is due to my misuse of the disks attached to the Pi. I have a AC/USB 2.5A capable power supply, which I connect to the Pi (USB). Then my HDD to the other USB port (it powers up the Pi when I attach the HDD, powers down when I detach it).

My way of "turning the Pi on" is merely by connecting the HDD to it through direct USB. To "turn the Pi off" (which I do whenever I am no longer using it), I just power down XBMC (throught the shutdown button), do a halt through ssh or unplug the HDD (when XBMC/remote crashes or I wish to power it down faster).

I believe the latter is causing the issues. Maybe hot-plugging on and off the HDD is not the way to go. Sometimes my TV remote does not (or no longer does) control XBMC and I have to restart it, and I do it by unplugging/plugging back the HDD.

Would too much of this start the disk making those clicks? Could it be power issues?
What is the recommended way to turn it off without hurting the hard disks?

If important, the screwed disks are WD and Toshiba (500GB) mobile (2.5"). Services I normally have on are only RPi-Monitor and (occasionally) Transmission.

Thanks!

[FTrevorGowen]

Somewhat reminiscent of my experiences with 2.5" disk-drive caddies using "Y-cables"**. Fortunately the drives "lost" in may case were old ones "recovered" from laptops and did not contain any critical data. The assumption behind such cabling is that two USB ports can supply twice the (max) current than one (1A cf. 500mA). For many, so-called "powered hubs" this is not the case, and I've discovered that all their ports appear to be connected in parallel (w.r.t. power). Long before the Pi appeared I used (and still use) a Linksys NSLU2 usb NAS that can power such drives directly. However that's even given problems long-term (more than a year of use) with one or two (recovered) drives. My current preferred solution is to externally power the drive before booting up the NAS (or Pi) and reverse that procedure on shutdown.
Trev.
**These work fine with laptops or netbooks which can provide the extra current.

[renne]

I believe this is due to my misuse of the disks attached to the Pi. I have a AC/USB 2.5A capable power supply, which I connect to the Pi (USB). Then my HDD to the other USB port (it powers up the Pi when I attach the HDD, powers down when I detach it).

I believe the latter is causing the issues. Maybe hot-plugging on and off the HDD is not the way to go. Sometimes my TV remote does not (or no longer does) control XBMC and I have to restart it, and I do it by unplugging/plugging back the HDD.

Do you back-power the RPi with the HDD or do you supply the HDD via the RPi?
Unplugging HDD or host (RPi) without unmounting the file-systems fries/degrades the file-systems.

Would too much of this start the disk making those clicks? Could it be power issues?

Possibilities are low voltage, overheating, vibrations, shocks (e.g. moving HDD while running) or overextended disks (e.g. running Notebook disks 24/7).

What is the recommended way to turn it off without hurting the hard disks?

Make sure file-systems are unmounted properly before detaching power. If XBMC fails to power down, use SSH.

[dropko]

@FTrevorGowen

I am not using a Y-cable... My Pi connects to the usb hub directly and my HDD connects directly to the Pi. There is no need for Y'ing, apparently. Just by connecting the HDD to the Pi (directly, no Y cable) makes both power up, and disconnecting powers them down. I bought that "psu" with (advertised) 2.5A in order to avoid any insufficient power issues. That single cabe is enough for power and data, and the disk never spins down indicating power shortage (if that would be such indication).

@renne

Do you back-power the RPi with the HDD or do you supply the HDD via the RPi?
Unplugging HDD or host (RPi) without unmounting the file-systems fries/degrades the file-systems.

It's as above. I supply the HDD via the Pi.

Possibilities are low voltage, overheating, vibrations, shocks (e.g. moving HDD while running) or overextended disks (e.g. running Notebook disks 24/7).

The disk stands still as a stone all day. Low voltage I would say is not an issue, but I can't be certain of it. Before my current setup, so said XBMC, I was seeing "disk disconnected / disk connected" all the time during normal play, and that is now gone.

Make sure file-systems are unmounted properly before detaching power. If XBMC fails to power down, use SSH.

Is a halt (shutdown -h) safe for power down? How about powering up, is it ok to just plug it in (like I would do in a PC/notebook)?
In my living room I have no easy access to an ssh, so that's quite inconvenient, that's why I just unplugged/replugged the USB cord...


Thanks both!

[FTrevorGowen]

@FTrevorGowen
I am not using a Y-cable... My Pi connects to the usb hub directly and my HDD connects directly to the Pi. There is no need for Y'ing, apparently. Just by connecting the HDD to the Pi (directly, no Y cable) makes both power up, and disconnecting powers them down. I bought that "psu" with (advertised) 2.5A in order to avoid any insufficient power issues. That single cabe is enough for power and data, and the disk never spins down indicating power shortage (if that would be such indication).
...

O.K., I wasn't assuming you were, just giving an example of a situation where (unexpected) insufficient (peak) currents gave rise to similar problems. So, in effect you're "back-powering" the Pi. The only issue I have with that is the "boot/power-up sequence is not "well-defined" ie. there's no guarantee that the HDD will "spin-up" etc. before the Pi is ready for it (that's why I power up my USB NAS drive before the NAS box itself which has led to much improved reliability). BTW, have you actually checked that the voltage between testpoints TP1 and TP2 is between 5.25V and 4.74V? It's possible that even a "good" 5V 2.5A PSU with a poor connecting cable may only be providing ~4.75 at the system's peak current. AIUT it's during "spin-up" that the greater current is taken. Once the drive is spinning (at a "constant" speed) the current should be lower & more stable.
Another source of "current spikes" (albeit, of lower magnitude) is when the heads are "seeking".
Trev.

[elatllat]

I have 10 drives that have been connected to one of my raspberrypis for 2 years with no problems.
None of them take power from usb, I blocked the USB power pin on the raspberrypi with some tape and paper, and they are all using a UPS.
According to this:
http://blog.backblaze.com/2014/01/21/wh ... uld-i-buy/
I'm lucky I never bought a 1.5TB drive.
And this:
http://static.googleusercontent.com/med ... ilures.pdf
Indicates there is not a lot you can do about the failure rate assuming clean power and low vibration/noise levels:
https://www.youtube.com/watch?v=tDacjrSCeq4

I have had luck with tapping a drive while it's off to un-stick the bearing and get it to spin up. there are stories of freezing drives, swapping platters (single only) without a clean room and swapping the board on the bottom, but I have never seen them first hand.

Drive failure sucks, rdiff-backup is nice.

[rpdom]

I have had luck with tapping a drive while it's off to un-stick the bearing and get it to spin up. there are stories of freezing drives, swapping platters (single only) without a clean room and swapping the board on the bottom, but I have never seen them first hand.

I have had some success in the past with freezing drives, swapping boards and even taking the top off and starting the platter spinning with a finger. All of these were on drives that would have otherwise be thrown away, and all except the one I changed the board on were only used to recover the data to a new drive, before disposing of the faulty one.

I once ran a HDD with the top off to see how long it would run without errors. I set it running a full kernel compile on a very slow PC with little memory (so lots of swapping as well). It ran for about 24 hours before I got a read error

Drive failure sucks, rdiff-backup is nice.

I usually use rsync to keep a copy of some systems, or the old dump program to write full or incremental backups to a server or even tape. But that's just what I use. The method isn't important (I've heard good things about rdiff-backup). Getting into the habit of making reliable backups on a regular basis is.

[dropko]

Thanks for all the information! I especially enjoyed the shouting at drives.

@FTrevorGowen:

So, in effect you're "back-powering" the Pi. The only issue I have with that is the "boot/power-up sequence is not "well-defined" ie. there's no guarantee that the HDD will "spin-up" etc. before the Pi is ready for it

So what is the recommended way to do it, supposing you connect directly (USB) and not through LAN?

BTW, have you actually checked that the voltage between testpoints TP1 and TP2 is between 5.25V and 4.74V?

I haven't. Does this involve a multimeter? That's a bit more technically-detailed that I was expecting to go... I could show the unit I am using but probably such a naming would not be forum-accepted.

@everyone:

I am aware of the importance of backups and how some drives can be "revigorated" using some techniques (I've seen quite a few videos where disks are recovered with bumps or shakes), but the information I'm really looking for is directly related to their usage with the Pi.

Connecting directly via USB (and not via LAN), what are the recommended best practices (for using with the Pi) in terms of connect / disconnect, power on / power off when using HDD in order to minimize / neutralize failures due to misuse (like the "clicks of death" I am having after short time).

Thanks

[rpdom]

Thanks for all the information! I especially enjoyed the shouting at drives.

@FTrevorGowen:

So, in effect you're "back-powering" the Pi. The only issue I have with that is the "boot/power-up sequence is not "well-defined" ie. there's no guarantee that the HDD will "spin-up" etc. before the Pi is ready for it

So what is the recommended way to do it, supposing you connect directly (USB) and not through LAN?

Adding "rootwait" to the line in /boot/cmdline.txt should make the kernel wait until the root device is available before continuing the boot sequence. It's been working for me for almost two years now.

[dropko]

Adding "rootwait" to the line in /boot/cmdline.txt should make the kernel wait until the root device is available before continuing the boot sequence. It's been working for me for almost two years now.

I looked up that line. Quite interesting, a useful tip, thanks. I found out also about a "rootdelay", whereas instead of waiting indefinetely (like rootwait), it merely delays it.

Still, how do you guys power up/down your Pi+HDD when using direct USB connection?

[GTR2Fan]

Still, how do you guys power up/down your Pi+HDD when using direct USB connection?

With the on/off switch on the front of my mains-powered HDD caddy.

It's a 3.5" caddy with an external high quality 12V 3A Ansmann switch-mode power brick. The caddy's internal 5V switch-mode regulator is rated at 3A, so I've rewired the caddy's USB port to back-power the Pi. As mine is an old Rev1 Pi with polyfuses on the USB ports, I've also had to bypass those with a soldered wire straight back to the underside of the +5V pin on the GPIO header.

The power button on the front of the caddy then powers the hard drive and Pi up/down together. The '/boot' partition still resides on a small SD card, but the OSes' '/root' partitions reside on the hard drive. I realise that that's no guarantee of corruption-free operation, but it's not failed me yet in several hundred power cycles, even though I seldom shut down the OS before powering down.

[dropko]

That still looks like a way advanced workaround. I am beginner level user, my setup is pretty basic, and I am not aiming at using additional hardware for powering up. Would that caddy do a "secure power off" of the disks when the switch is changed to 'off'? Is it any better than just unplugging the USB by hand? It sounds a very hardcore shutdown, to use that switch...

Are you telling me the Pi is a disk corrupter by nature unless I add externally controlled power to the disks?

So far what I've understood as best things to do in a "standard setup" are:

a) Adding "rootwait" to the line in /boot/cmdline.txt
b) Shutdown through XBMC's shutdown or ssh halt for graceful spin down of disks.
c) Turn on by... just connecting disk through USB?

Bad things:

a) just unplugging the usb cord between Pi and HDD (here it seems awfully similar to switch off a caddy or any external powering to the disk).

[GTR2Fan]

It sounds a very hardcore shutdown, to use that switch... just unplugging the usb cord between Pi and HDD (here it seems awfully similar to switch off a caddy or any external powering to the disk).

The on/off switch on this caddy is an electronically-controlled clean shutdown of the power rails, and this particular caddy had previously been in almost daily usage since 2005(?) with various PCs for backup purposes with possibly several thousand non-destructive power cyclings via this on/off switch in that time. Physically yanking a plug out is very different from a clean and controlled power rail shutdown.

I understand that it may not fit into the beginner category in terms of modding, but you did ask, so I'm just pointing out one seemingly successful method of achieving what you asked. Hopefully others will share theirs.

[dropko]

Would it be against the rules if you could provide links to stores or sites selling or showcasing that hardware you mention?

[rpdom]

On my main Pi I have an old external CD-ROM case in which I've mounted the 3.5" HD. I then connected a USB socket to the 5V and 0V lines of the case supply to power my Pi from. The Pi has a cheap USB to IDE/SATA cable connected to the disk.

The switch is just a normal mains power switch that turns of power to the PSU. Nothing fancy. Turning on the switch starts up the disk and Pi. I use "halt" on the Pi to shut it down, then turn off the power switch. The disk is around 10 years old and running fine.

If the Pi crashes I just turn off the power. I've never had any serious file system corruption or damaged disks this way. Modern hard disks are designed to cope with unexpected power loss and shut down as cleanly as they can. Not like the old days where you'd often get a fatal head crash if you didn't tell it to park the heads before powering off.

[ame]

I recently discovered I just needed a beefier PSU to make my Pi + USB hard drive go. Until now I had used two power supplies: one for the Pi (about 1A), and one for the USB HDD caddy (about 2A). I needed this as the 2A PSU was not sufficient to run the hard drive and the Pi at the same time. I modified a USB cable for the hard drive so that the +5V line was cut but the two data lines and ground were left alone. This ensured the hard drive and Pi powers supplies were independent.

Today I tried a 3A USB PSU, since I happened to have one. It's perfect! I can power the Pi from its micro-USB power input socket, and the hard drive takes power directly from the Pi USB port. No splitters/adaptors or headaches.

I'll try it like this for a while longer and see how it behaves. My biggest problem was getting everything started at boot time, but occasionally the hard drive would disappear (then I couldn't replug it). It's a media centre, so it's on all the time, and it's easy to spot when the hard drive decides to stop responding.

[dropko]

I recently discovered I just needed a beefier PSU to make my Pi + USB hard drive go. Until now I had used two power supplies: one for the Pi (about 1A), and one for the USB HDD caddy (about 2A). I needed this as the 2A PSU was not sufficient to run the hard drive and the Pi at the same time. I modified a USB cable for the hard drive so that the +5V line was cut but the two data lines and ground were left alone. This ensured the hard drive and Pi powers supplies were independent.

Today I tried a 3A USB PSU, since I happened to have one. It's perfect! I can power the Pi from its micro-USB power input socket, and the hard drive takes power directly from the Pi USB port. No splitters/adaptors or headaches.

I'll try it like this for a while longer and see how it behaves. My biggest problem was getting everything started at boot time, but occasionally the hard drive would disappear (then I couldn't replug it). It's a media centre, so it's on all the time, and it's easy to spot when the hard drive decides to stop responding.

this is more like my setup.

how do you control your power ups/downs of the Pi?
does your Pi shutdown if you unplug your HDD?
ever remove USB when system is all powered (e.g. to shut it down)?

[ame]

this is more like my setup.

how do you control your power ups/downs of the Pi?
does your Pi shutdown if you unplug your HDD?
ever remove USB when system is all powered (e.g. to shut it down)?

So far I have only tried it a couple of times, since the 3A PSU only recently became available.

To turn on: plug HDD into Pi USB port. Plug PSU into Pi microUSB power input.
Unplugging HDD: Haven't tried
Replugging HDD: Haven't tried

Generally I would never unplug the HDD if it was running. I would try to unmount it first. However, sometimes the HDD becomes unmounted due to some problem I don't understand, so I can unplug and replug it, but it was never re-detected properly. Sometimes the Pi goes a bit mad, so I cannot issue a shutdown command. In that case I just pull out the power plug. I hope that with this bigger PSU the problem will not happen.

Finally, this Pi is set up as a media server, and I never intend to turn it off or unplug the HDD. It runs 24/7 playing music or movies when I want to. The HDD is an old one from a dead laptop and there is nothing important on it (the contents are backed up somewhere else). If the HDD dies I will find another one.

[elatllat]

Are you telling me the Pi is a disk corrupter by nature

Firstly there is a big difference between a dead drive("clicking sound of death"/no spin up, smart data fail, etc) and corrupt data.
The Pi won't normally do either of these things.
(With old firmware it could corrupt an sdcard but that's another topic)

Just like any other system data corruption is a result of simple software and a hard off while writing, so just unmount your drives before unplugging or switching them off. Enable Journaling http://en.wikipedia.org/wiki/Journaling_file_system etc if you really don't want corruption. Use a UPS to auto unmount and clean shutdown on power failure.

Regarding dead drives, a clean power source (UPS) is the best way to protect your drives, and if you block the power line from the pi to other USB devices the pi won't be able to dirty the drive power. If your drive did not come with it's own PSU buy it it's own and not some dangerous fake from china/etc. If struck by lightning the pi might break the drives via the data lines but short of drive on a fiber channel (crazy pricy overkill) that's the best you can do.

Bottom line is that your drives if broken were probably not broken by the pi.

[ame]

Well, this is odd. I powered everything up exactly as before, with my *super* 3A PSU, but the HDD wouldn't spin up. It sat there flashing its LED and the Pi wouldn't mount it.

When I unplugged the HDD and plugged it in again the power drooped (due to the high current requirements of the HDD) and the Pi reset. Still it wouldn't mount.

So, I unplugged everything and tried with my (previously not grunty enough) 2A PSU, with a Y-cable to power the HDD and back-power the Pi. Presto! It all worked. This same setup did not work yesterday.

Spooky.

[dropko]

Talk of th devil...

What seems impressive is so many people running externally powered PSUs.
That's not really what I am aiming for (my Pi is very travelled and I prefer the convenience of "mobile" HDD too).

and if you block the power line from the pi to other USB devices the pi won't be able to dirty the drive power.

what do you mean by this?

[elatllat]

If you are having power issues isolating the power from pi to usb drives can help... there were some old threds about this somewhere...

http://www.addonics.com/technologies/im ... ut_lrg.jpg

blocking or cutting vcc will keep you drives and pi from killing eachother if one of them or your psu acts up.

[dropko]

the point is that is to ensure that the power for the HDD is coming from external source (PSU) and not from the Pi?

is this why the Pi shuts down if I just disconnect the HDD? Both ports have some kind of shared resource that causes this?

This is quite the extreme solution, would ruin one of the ports...

[rpdom]

You don't need to damage any of the ports. Just a cable. Make a careful cut in the outer insulation, pull out a bit of the red wire, cut the wire and carefully isolate it with tape. Make sure it can't touch anything else, like the braided shield around the cable.

[elatllat]

Or like I said before a small pice of paper and tape strategicly placed.