why the light of my harddisk be lighted every 5 seconds?(I installed the FedoraCore2)
 

I am using the Fedora Core release 2, but i find the light of my harddisk would be lighted every 5 seconds.
it seems that something access the harddisk periodically .
My hardisk runs well under the OS windows .

how to fix it ?

Thanks very much :)

There are two likely candidates here; swapping and log-files.

In a terminal, run the command:, and look at the value of “SwapFree”, if it's less than “SwapTotal” then your computer is running out of RAM, and using the hard-disk as a back-up store (just as Windows would). You could free more memory by stopping daemon services you're not using.

The other option is that you have a process writing to a log-file about once every five seconds. Take a look at the /var/log/messages file and see if you're getting any repeated error messages.

Hope that helps,

— Robert J. Lee

Or it could just be that you're using your PC. Anything that involves reading or writing data to the disk will cause the light to flash briefly. If you're surfing the web, the various images you view will be written to your browser's cache, causing the light to blink. Similarly, if you are playing some mp3's that you've got stored on your machine, then in order for the music to keep coming, your system will be reading from the hard drive.

My question would be: Are you saying the light flashes continuously at regular 5 second intervals, or are you using the phrase "it flashes every 5 seconds" to mean "it flashes frequently"? Also, if you leave your PC totally idle for 1 minute (no keystrokes, no mouse movement, no apps running) does the flashing stop? If so, I wouldn't worry about it; if not, and the light continues to flash, then it appears that there may be some other process running as rjlee suggested. You can use the command "top" to show what process is using the most CPU, and similarly you can run the command "ps -ax" to show all processes that are running on your system.

As a general comment, seeing the hard disk light flash while you're actively using your PC is totally normal. On the other hand, if it regularly flashes at short, consistent time intervals even when you are not running anything, then I would agree that would be unexpected. -- J.W.

Did you know it is consider impolite to post the same question more than once in different forums you should only ask the question once in the forum that most applies to your problem. You can see your other thread for my reply http://www.linuxquestions.org/questi...hreadid=212785 .

Thank you for your reply:)
the phrase "it flashes every 5 seconds" means "it flashes frequently" even i do nothing on my PC.
I am a newbie to Linux.
I ran the command "ps -ax",but how can i find that process cause the problem?

The "ps -ax" command just lists the different processes that are running, it won't necessarily indicate which one may be accessing the drive. It would be tough to try to make a guess about which process might be running and causing the light to flash, but then again, as long as the system performance is normal, and you don't notice anything unusual in terms of behavior, I don't know that it is worth worrying about because it's normal to have the hard disk light come on every so often while you're using your PC. Apart from noticing that the light comes on from time to time, is there any indication of abnormal system behavior? Overall, the situation you describe sounds perfectly ordinary. -- J.W.

ahh..
I think there may be something wrong to express my idea ------my english is poor .
my problem is :

The light of my pc always flash every 5 seconds.
This phenomena exist persistently, even i do nothing on the PC.
There isn't any abnormal system behavior except the hard disk light flash.

There may be nobody meet this problem who installed the Fedora Core 2 , but i do :(
I am worry about my hard disk because the system access it very frequently.
My file system is ext3.

All I can say is that there must be some process that is doing I/O on your drive, which would cause the light to flash. Apart from that though, I'm afraid I really don't have any other advice to offer. Maybe if you listed everything you've got running, someone would be able to point out a process that does I/O -- J.W.

Thanks very much for your help :)
This site is a good place for linux learning.

Hi, I had the same problem, completely solved it by adding the noatime option to all my ext3 file systems in the /etc/fstab. Example follows. Make sure you do it to all ext3s. If you already have an option listed then add ",noatime" without spaces after the one that is already there. If "defaults" is the only option, then replace it with noatime. You'll need to reboot for it to start working.

LABEL=/ / ext3 noatime 1 1
LABEL=/boot /boot ext3 noatime 1 2

Problem was solved !

Thank you very much :)

theapp - congrats on solving the problem, and thanks for posting back with the solution, as that will be of great assistance to any future visitors.

randyding - nice save!

-- J.W.

I've got exactly the same problem as this running SUSE 9.1. It's using reiserfs .

2 questions I'm hoping someone can help with:
- Would this work with reiserfs?
- What does that noatime option do?

Well, uh make that 3 questions:
- Are there any other file systems that I would add this option to? I also have vfat, ntfs.

TIA
ws

Whenever you open a file, the UNIX specification says that the time of last access for the file must be written to the disk. The noatime option turns this “feature” off.

Journelling filesystems have a special journal file that stores when each file was used; this is flushed to disk every few seconds regardless of if files are being used or not. The noatime option stops this flushing from causing a write (of the last access time) and hence stopping the disk write every few seconds.

noatime never really does anything bad (because no-one ever uses the access time), so you might as well try it and see.

Ahah! Thanks for the reply - now I understand what it's trying to do.

I changed my etc/fstab from
/dev/hda4 / reiserfs defaults 1 1
to read
/dev/hda4 / reiserfs noatime 1 1
and also
/dev/hda4 / reiserfs defaults,noatime 1 1
and rebooted each time.

But I'm still getting the 5 second blip.

Dammit! I think I found it!
My /var/log/acpid file is freakin huge! 313 MB
and I'm getting things like:
I had a look at the manpage, but seems there's only options to increase the logging ? :(

SUSE seems to have the config available via /etc/sysconfig/powermanegement , but again there doesn't seem to be anything to stop this ?

Help?

TIA
ws