Bursts of I/O kills DVB recording and other functions

[e8hffff]

I gets bursts of I/O that causes the hard drive light to stay on for a few seconds. It's killing recording TV on my DVB card. Obviously the BUS is being bottlenecked and not sure why. I've reinstalled Beta twice and same problem.

Using a i7 920 intel based motherboard. The hardware worked perfect on other versions of Kubuntu.

I can't report this bug as Geany has taken over the file-type for bug reporting in KDE. Also the method to report bugs is problematic on Kubuntu.org.

I also get a similar problem when deleting files. The hard drive goes crazy as if it's moving the file with a copy to the trash rather then changing the details of the file to suit other directory needed in delete process.

[dibl]

Re: Bursts of I/O kills DVB recording and other functions

One possibility is that strigi is running indexing for the nepomuk desktop search function. This only needs to happen once in a major way, on a new installation, and then afterward it merely updates the database. If you don't want nepomuk, you can (I am sure) disable it and the strigi daemon -- google can probably help you figure that out.

Also, if you run top or htop and observe what is going on, if you can catch it when the big I/O activity starts, you might be able to determine what the source of it is.

[e8hffff]

Re: Bursts of I/O kills DVB recording and other functions

One possibility is that strigi is running indexing for the nepomuk desktop search function. This only needs to happen once in a major way, on a new installation, and then afterward it merely updates the database. If you don't want nepomuk, you can (I am sure) disable it and the strigi daemon -- google can probably help you figure that out.

Also, if you run top or htop and observe what is going on, if you can catch it when the big I/O activity starts, you might be able to determine what the source of it is.

Ok many thanks will try your suggestions

[e8hffff]

Re: Bursts of I/O kills DVB recording and other functions

It seems to be caused by 'jbd2' when analysing with iotop.

jbd = 'Journaling Block Device'

I've read that it maybe causing logs to be written. so trying to find them now to see if errors are being produced or logs mode is too verbose.

[dibl]

Re: Bursts of I/O kills DVB recording and other functions

Huh -- yes, Wikipedia informs me that jbd2 is the kernel journaling layer for ext4. I never knew that -- I've never heard of that being a source of excessive I/O, and I've never observed the process anywhere near the upper regions of a top list. I just checked top on my running system and jbd2 is way down in the root processes, maybe 40 or 50 processes down the root list.

Is your hard drive OK -- any reason to wonder about it?

[e8hffff]

Re: Bursts of I/O kills DVB recording and other functions

Is your hard drive OK -- any reason to wonder about it?

Should be ok. The checks done periodically result in ok reports.


I've deleted all my logs in /var/log retaining folders only so errors are produced when new logs are needed to be made. So far no errors produced but still getting high I/O at times when recording on DVB card. Stringi is off.

[dibl]

Re: Bursts of I/O kills DVB recording and other functions

Does the huge I/O only begin after you start recording from DVB? I wonder if there is some cause - effect relationship there?

One thing you could do that would let you do the recording is to turn off the ext4 journal. Of course, like all choices, that one has consequences -- a power loss would be a catastrophe for your filesystem. But as long as nothing bad happens while it's running, you should be able to record without the I/O interruption happening.