linuxgeek: Re: [nslu2-linux] Slug hangs when trying to create directory on a 1Tb ext3 drive

Monday, September 28, 2009

Re: [nslu2-linux] Slug hangs when trying to create directory on a 1Tb ext3 drive

gullaugu wrote:
> I am running slugosBE 5.3 and have nfs and samba set up. Recently, trying to create a directory through nfs freezes the slug and only plugging the cord works for getting it back. ssh won't work and I don't have a serial cable. Trying to create a directory directly from the slug doesn't freeze it, but the ssh connection is reset and I can't log in again. But the power button actually does its thing. Connecting that same drive to my laptop (after fsck) and I can create the directory.
>
> The drive is 1Tb and using the ext3 file system. Is there a limitation to the number of directories on the slug? Does anyone have a fix for this? I hate to have to connect the drive to my laptop to create directories.

You're almost certainly running into limitations in terms of physical
memory. There are no limitations to the number of directories. Rather,
there are limitations in that in order to perform certain operations,
the filesystem code needs to have certain data structures in-memory.
And when memory is in such short supply, the result is often bad,
triggering the kernel Out-of-Memory Killer process (which is most likely
the cause of the symptoms you describe).

You can try to enable swap -- but since your issue is happening on the
drive's filesystem, you probably want a swap partition, not a swap file.

You can try using an ext2 instead of ext3 filesystem; some small amount
of memory might be saved by not having the journal. You might try
another filesystem format altogether; perhaps jfs handles large
partitions in a less memory-intensive fashion. But the best solution is
probably to re-partition the drive to smaller partitions; a pair of
500MB partitions might work, but I would use nothing larger than 250GB
(which seems to be the largest size that can actually be fsck'd on the
NSLU2 without running out of memory).

-Mike (mwester)