Random access by filename was fast, since we used a hashing mechanism to locate the directory quickly. But (what I meant with "browsing") was slow backup and slow inspection using normal shell tools.
Yes I understood the issue, I specifically asked how many files you were storing per directory - if directory scanning is slow, you still have too many files per directory.
I can't really remember, but we had tens of millions of files and the directory depth was 2, so there were approx. 80000 files in each directory (we used an md5 checksum for the directories). And we used ext3. I understand that the speed with large directories was increased in ext4... maybe that was the problem back then.
