I was copying files to a directory remote with git annex copy. Out of 114 files, 9 of them failed with no message, just:

copy data/foo.dat (to usbdrive...) failed
copy data/bar.dat (to usbdrive...) failed

According to strace:

31338 mkdir("/media/annex/Zp/9v/SHA256-s1362999320--d650297c8cf8c2dc0575110a52d0c5cc0ff266f294a0599f85796a6b44b23492", 0777) = -1 ENOENT (No such file or directory)
31338 mkdir("/media/annex/Zp/9v", 0777) = -1 ENOENT (No such file or directory)
31338 mkdir("/media/annex/Zp", 0777)    = -1 EEXIST (File exists)
31338 stat("/media/annex/Zp", 0x7f8449f170d0) = -1 ENOENT (No such file or directory)

The filesystem is FAT32 and has weird case semantics. This was mounted by udisks with its default options:

/dev/sdb1 on /media/annex type vfat (rw,nosuid,nodev,uhelper=udisks,uid=1000,gid=1000,shortname=mixed,dmask=0077,utf8=1,showexec)

I wonder if the directory remote should use hashDirLower instead of hashDirMixed?

git-annex intentionally uses the same layout for directory and rsync special remotes as it does for the .git/annex directory. As far as I know it works ok on case-insensative filesystems.

Based on your strace, if you ls /media/annex/Zp, you will see "No such file or directory", but if you mkdir /media/annex/Zp it will fail with "File exists". Doesn't make much sense to me.

I cannot reproduce this problem using a vfat filesystem mounted using the same options you show (linux 3.0.0). --Joey