I've recently noticed that the hard drive on my laptop is periodically being used on its own. Normally I wouldn't mind about it, but the frequency of the usage is giving me suspicions. The hard drive isn't being accessed all the time, but after a while of being idle it starts to do some continuous activity that lasts for about one minute each time. Then it goes away, and comes back in random time intervals (mostly rounded down to a minute). I don't have to do anything special to trigger it, all that's needed is to allow linux to boot into a terminal and wait. I don't even have to login.

I know the disk is definitely doing something because it starts to emit this buzzing sound that goes like bzzzzzzztzzzzzzzzzbzzzzzzzzztzzzzzzzzzbzzzzzz... Putting my ear ontop of the laptop case where the HDD is located suggests that the disk is buzzing as if the heads were doing I/O, but there's something else in there that's constantly being turned on and off. What's bizzare is that during this activity the HDD led isn't even blinking (it does blink during normal I/O). If any process happens to do read or write to the HDD while this activity is taking place, the buzzing gets interrupted and stops immediately. If I issue a command like "hdparm -y /dev/hda" as root, the buzzing also stops and the HDD spins down. Eventually some process will want to do r/w to the drive and spins it back up. After a while of inactivity it's the same old story.

I've looked for the source of the problem by monitoring disk traffic of various processes with tools like top, vmstat, atop, iostat, htop, etc, but none of these show any useful information. Actually the only useful piece of information I got was that none of the processes were accessing the disk. I've even done "echo 1 > /proc/sys/vm/block_dump", but dmesg shows no entires at all during activity. It's almost like some invisible I/O is taking place though I'm not sure it's I/O at all. I suspect that whatever is happening is being done by the kernel, and it makes me think of that bug that Ubuntu had, where the HDD heads were constantly being parked and unparked due to some weird power management settings. Could this be it? I'm being a bit paranoid here and worry that this could shorten the lifetime of my HDD.

Here's a summary of what I know about this disk activity:

• Starts after a while of HDD inactivity (disk still spinning)
• Mostly lasts for about a minute unless it gets interrupted somehow
• Mostly starts in X minute intervals, X = 2, 3, 4, ...
• While ongoing, the HDD LED doesn't blink (does so when user is doing normal I/O)
• While ongoing, the HDD emits continuous buzzing sound
• Doesn't seem to be caused by a process doing r/w (doesn't show on system monitors)
• Stops immediately when some normal disk I/O takes place

I'm not asking for a perfect answer here because I know I'll probably never get it, but at least some pointers could be handy. I am willing to go to the point of recompiling the whole kernel for the sole purpose of identifying what's going on here (have full kernel source ready), but I'll need some help. How can I track any kind of access to the hdd, and most importantly what's causing it? My kernel is 2.6.30.

Thanks in advance.

hi

troubleshoot your suspect causes to see if you can eliminate or confirm them?

write down everything you attempt and the order so you have an audit trail?

1) install or run a different distro...to see if its a Ubuntu powermanagement issue.

2) Check all current services....turn off all that you dare....especially turn off cron and anacron and see if that make differences

3) could it be a fan?

do you have a mp3 player that can record? tape a small bit when off and on and upload it somewhere...even youtube...lol

4) it sounds like you have a lot of monitoring going on....and so they start up every so often...say a minute or so...and so worsen the original fault

If you're worried, here's one check...

Open a terminal with root privileges and use the command "lshw" to find the make and model of you HDD, then see if the HDD maker has a diagnostic program you can download and run to check the HDD as a device.

I suspect that it's probably a fan. You shouldn't need to put your ear to anything for the HDD. And most laptop HDDs are pretty silent these days. Plus there's a light for HDD activity on the front. Alternatively turn off all unused services. If my router is any indication /var/log/messages gets updated during long idle periods -------- MARK ---------. And cron likes to run a lot of junk at 6:25am. Which on my router (desktop) is loud enough to wake the dead. And I'm usually dead at that time of day.

If this noise is new and/or louder than usual, you're probably due for a cleaning. Laptop fans are only rated for one year (note the warranty). Most times they just get clogged with dust since the vent grill is too small to let the dust escape. Keep that clean and keep your laptop happy and quiet. And otherwise run your laptop for three years until your battery goes bunk.

HTH

"Buzzing sound" doesn't seem to me like the typical click of death, which would certainly be a bad sign. A dying hard disk usually sounds this way:

http://upload.wikimedia.org/wikipedi...k_of_death.ogg

In Linux you can use smartmontools to check the health of your hd, it's not infallible (nothing is when it comes to faulty hardware) but it can help sometimes.

My guess too. Given that the sound occurs independently of hard drive activity, it seems unlikely that the drive is causing the noise, particularly if the sound is still being produced even when the machine is completely idle. Instead, I'd guess that it's simply a normal issue of the fan spinning up when your system temperatures reach a certain point. Have you checked your system temps? (If not, I'd highly recommend an excellent little utility called gkrellm)

I suppose that if you wanted to test the theory, you could put your hand across the vent for a minute or so, and see if the sound continues. If it is from the fan, then the sound should continue longer than normal. Obviously I don't recommend doing this for an extended period of time, as you could fry your equipment.

Thanks for the suggestions!

It's an old and used computer with an old HDD - a HP Compaq NX6110 that I've bought from a friend. I'm pretty certain it was the HDD, not the fan because the main CPU fan is located on the other side of the laptop and the HDD doesn't have one. Still, I fear I have some bad news. I've suspected that it was a linux driver causing the sounds, but I've just booted the laptop into bios today and after a couple of minutes the same sound was heard again - this probably means linux doesn't have anything to do with it, it's probably the old HDD itself.

Here's how it sounds like: http://www.filedropper.com/hddbuzzing
Note how it suddenly starts, and how it later terminates as a result of running the "hdparm -y /dev/hda" command.

If it works try running 'smartctl -a /dev/hda', maybe that will tell you something. But, from the sound of it, backup now !