From:    Antony Stone <Antony.Stone@???>

Date:    Sat, 11 Oct 2025 10:45:23 +0200

> With an EXTn file system, and especially over NFS, more files per
> directory is the *last* thing I need.

My knowledge of the limits of the various Ext systems is minimal. In
https://en.wikipedia.org/wiki/Ext2 "Directory indexing is not
available in ext2, so there are performance issues for directories
with a large number of files (>10,000). The theoretical limit on the
number of files in a directory is 1.3 * 10^20,[original research?]
although this is not relevant for practical situations."

Appears that in Ext4, files per directory won't be a problem.

With network involvement, Lustre might help.
https://en.wikipedia.org/wiki/Lustre_(file_system)

> I already end up with >20,000 files in a single directory for some
> purposes.

If the filesystem is used to organize data, an alternative to consider
is organization independent of the filesystem. Something more
intrinsic to the context.

> Also, if my . file containing the directory itself gets corrupted,
> I'm a lot worse off, the more files there were listed in it.

Yes, reliable backup is essential.

Regards,                   ... P.

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