"IOError : too much files open" coming iteratly

ericj · Post by **ericj** » Thu Apr 06, 2006 9:41 am

Hi,

I'm using brainvisa essentialy for morphometry. I'm not going really deep into the software as I am only using anatomical pipelines. I'm running Brainvisa on a Asus Laptop, with an AMD turion 64, 1GO Ram and nvidia graphics card. It relies on double booting with XP and Fedora Core 4. I'm experiencing some kind of trouble often enough to be quiet disabling. Sometimes, when lauching any routine from brainvisa, I get an error : "IOError : too much files open". It then keeps coming and preventing any routine to begin until I quit. Sometimes I'm even forced to quit the session.
Any one have ever heard of this ? Is this a Brainvisa problem ? or a Fedora one ? I have just redone a complete install from scratch but the problem is still occuring.

Best regards,
Eric Jouvent

Manik · Post by **Manik** » Thu Apr 06, 2006 11:37 am

This error is reported by python because the maximum number of open files was reached.
This is really strange, as it is usually a very large number.
To see the current value of the maximum :
cat /proc/sys/fs/file-max (you may need to be root)
The value returned is 102530 on my computer, how much is it on yours ? Fedora probably gives this a correct value, but just in case, could you check this ?

ericj · Post by **ericj** » Fri Apr 07, 2006 9:22 am

thanks for your quick answer,

I've checked for this, and the number I have is rather large too. More than 100 000 as yours. I still don't understand what's happening. Do you think it could come from the fact that my databases are on an external drive ? I don't…

Best regards
Eric Jouvent

Manik · Post by **Manik** » Fri Apr 07, 2006 10:17 am

I had a lot of problems using an external drive for the Brainvisa database, but it was because it was formatted for windows (fat32 filesystem) and not for linux. As long as yours is ext2/ext3/reiserfs it should not be a problem.
Or maybe there is a per-drive limit as well ? How do you mount your external drive ? If it is automatic, it is probably using automount or something like this; I had a few problems with this (I never tried with Brainvisa), so in that case you should try to umount your disk and remounting it manually using mount /dev/yourDisk /yourPath

ericj · Post by **ericj** » Tue Apr 11, 2006 8:08 am

In fact the problem occured with a FAT32 formated external drive. I've reformated it in ext2. I let you know if the problem is fixed. Right now it seems to work fine.
Thanks again for your help

Sincerely
Eric Jouvent

Post by **riviere** » Wed Apr 12, 2006 3:09 pm

Hi,

There are limits on the number of open files on the system, but also process-by-process limits: use the command 'limit' to see it (generally: 1024 descriptors).
Now the question is: why is this limit reached ? We have never experienced this problem...
Does it occur during the morphometry process execution (so in a C++ commandline) or in brainvisa in general (then, in python code) ?

Denis

Jean-Francois Mangin · Wed Apr 12, 2006 4:24 pm

As far as I remember when I saw this stuff happening, we get a python message...

ericj · Post by **ericj** » Thu May 04, 2006 7:32 am

It's been two weeks without any problem since I changed the format of my external drives. It's really an amazing stuff…

Kind regards
eric jouvent