Re: Where all does preallocated/extra space hide?

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Eric Sandeen wrote:
I was running some of the xfstests enospc tests on ext4, and they were
failing; in one case, manymanymany small files are made to fill up a
100M filesystem.  ext4 stops quite early with -ENOSPC, but after a bit,
(or after a "sync") we get 40MB free again.  So 40% of the fs space is
hidden somewhere in preallocation...

I tried calling out to discard group prealloc but that's only a few
blocks.  I'll go trace through the sync paths to see what all gets
released, but if anyone knows offhand where the rest of that space is
hiding, please give me a shout.  :)

Thanks,
-Eric

Possibly related; on a 1G filesystem, doing this:

#!/bin/bash

xfs_io -F -f -d -c 'pwrite -b 64k 0 512m' /mnt/test/io_test
rm /mnt/test/io_test

in a "while true" loop spews ENOSPC. (it's a direct IO 512m write in 64k chunks). Buffered IO seems fine ...

-Eric
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html

[Index of Archives]     [Reiser Filesystem Development]     [Ceph FS]     [Kernel Newbies]     [Security]     [Netfilter]     [Bugtraq]     [Linux FS]     [Yosemite National Park]     [MIPS Linux]     [ARM Linux]     [Linux Security]     [Linux RAID]     [Samba]     [Device Mapper]     [Linux Media]

  Powered by Linux