On an older Linux box I have, there is an NFS mount of a Netapp. Once there are 100k files in a single directory on this box, files can no longer be written. Anyone know what might be causing this? I have been told symbolic links can still be written.
I will add more specific information as I look it up. Please, skip the 'use a better a file / folder structure and/or database', I know ...
You've consumed all of the available inodes for that volume. You can confirm this with the commands df -i and maxfiles.
maxdirsize (more likely)
ONTAP imposes a limit on size of directories. Size being a product of metadata/hardlinks, not file content. This limit defaults (assuming >6.5) to 1% of your system RAM. It does so to ensure that large directories don't impact system performance. Because linear directory scans require directory data structures to be loaded into memory. Quick overview:
You can check a directory size with ls -lkd.
Raising maxdirsize for a volume is a bit of a one way operation.
Only raise it in small increments.
You can't reduce a directory's size by deleting it's contents.
I have these two bookmarked links which contain a lot more information.
Starting with Data ONTAP 6.5, the
maximum number of subdirectories a
single directory may have is 99998
(100K). Data ONTAP 6.4 and earlier
versions were restricted to 65534
(64K) subdirectories. This number may
not be changed. To understand the
reason for this limit, see the section
below on hard links and subdirectory