If you are using ext3 then you will get an EMLINK error at 32000 subdirs. If you are using ext4 with the "dir_nlink" feature enabled then you can create several million subdirs if you want. As for performance, if you are not regularly creating and deleting the directory I don't think you would even notice the performance difference of a large directory. The create and unlink rate get somewhat slower at 100k files (from 25k/sec to 10k/sec) and 1M entries or so (to 5k/sec). For lookups the whole directory will easily fit into cache (at about 40MB for 1M entries) so the lookup rate is not affected much by size. Cheers, Andreas > On Feb 14, 2015, at 03:17, suntrop@xxxxxx wrote: > > Sorry for confusion, but now I am confused :-) My setup will be like > /files/ > /files/1/ > /files/2/ > /files/3/ > (...) > /files/24244/ > (...) > /files/113524/ > > Thus all folders reside within the /files/ directory (can't change that). > What happens when the max link count reach 32,000 and I create more folders? Will this result in any errors or problems? I’m using ext3. Is the only consequence that the links aren’t counting up any more, like ext4? > > > > Gesendet: Freitag, 13. Februar 2015 um 18:28 Uhr > Von: "Eric Sandeen" <sandeen@xxxxxxxxxx> > An: suntrop@xxxxxx, "Andreas Dilger" <adilger@xxxxxxxxx> > Cc: "linux-ext4@xxxxxxxxxxxxxxx" <linux-ext4@xxxxxxxxxxxxxxx> > Betreff: Re: File limit inside a single directory >> On 2/13/15 10:49 AM, suntrop@xxxxxx wrote: >> Thanks guys. I was afraid of having a couple 100K (at most). The >> server support team told me not to have more than 10 to 20K. There >> seems to be a misconception (for me and people from the CMS) about >> the 32K subdirectory limit, but this ins't for files/folders within a >> single directory but rather nested directories like /1/2/3.../32000 > > You've confused things a bit here, FWIW. > > The 32k (well, 32000 because, sure) limit on ext3 is max link count; > each subdirectory increases the link count on its parent, but only > its parent. It's not about deep nesting, or about files in a dir. > It's only about subdirs in a parent dir. > > # mkdir dir > # stat dir | grep Links > Device: fd06h/64774d Inode: 2490391 Links: 2 // . and .. entries > # mkdir dir/subdir1 dir/subdir2 dir/subdir3 > # stat dir | grep Links > Device: fd06h/64774d Inode: 2490391 Links: 5 > # mkdir dir/subdir1/subsubdir1 dir/subdir1/subsubdir2 dir/subdir1/subsubdir3 > # stat dir | grep Links > Device: fd06h/64774d Inode: 2490391 Links: 5 > > ext4 bumped that max to 64000, and just stops counting if that number > gets exceeded... > > -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
