why is samba so slow with many files in one directory?

[David Collier-Brown]

Jeremy Allison wrote:> 
> Nope, I don't think so. Look at the kernel mailing lists for comments
> comments about ext2fs performance with 10,000+ files - it sucks.
> The developers consider this a broken application decision (ie. storing
> that many files in a directory for an application, rightly
> or wrongly). Try doing a regular ls of a directory with that many files,
> time it and then see if Samba is using equivalent time (I bet it is).

	Yup! In scanning a directory of 85,783 files,
 
				real	user	sys
	smbclient took         43.11s 	4.59s	3.55s
	ls -l took	     1m46.69s   42.33s  10.40s
	ls took		       19.49s 	3.16s	0.82s

	smbclient does a readdir and a stat for each file, as
	does ls -l: the getdents times are equivalent, the
	difference is in the formatting and sorting.

	Very very roughly, ls takes  .000272 second/dir entry
	for this size directory.  The directory size is 1369088,
	so that's roughly 70 KB/S. Ext2fs is only slightly faster
	at reading than ufs, so I expect similar times. 

	Hint: if your directory needs indirect blocks, it's
	**way** too big!

--dave
-- 
David Collier-Brown,  | Always do right. This will gratify some people
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