Hello.

I have been using a portable USB disc for storing media. After several weeks of inactivity, when I used it with git-annex again I noticed it was running very slowly. I mean, it is an USB 2.0 connection, `git-annex sync` would take a few minutes, but now it takes *many hours*.

When adding files to it (`git-annex add`), I would see the list of files passing by at the speed I would expect, but then, at the end, I would have to wait; the next day I saw the operation had completed. `git-annex status` makes me wait a similar amount of time, and `git-annex sync` also makes me wait, even when it has nothing to do — I saw `top` reporting 100% CPU usage, `iotop` saying `git` and `fuse` were saturating the USB connection to its maximum.

File operations outside of `git-annex` seem to work fine, so I can't blame the hardware or the filesystem (NTFS mounted with `fuse`).

I would like to know your thought about this problem, that I was not noticing before. Here is the regular information to help you form an oppinion:

    % time git annex status --debug
    [2016-09-07 20:20:46.093990203] read: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","-c","core.bare=false","status","-uall","-z"]
    [2016-09-08 15:05:23.239573491] chat: git ["--git-dir=.git","--work-tree=.","--literal-pathspecs","-c","core.bare=false","cat-file","--batch"]
    [2016-09-08 15:08:25.605689622] process done ExitSuccess
    git annex status --debug  33802.97s user 1162.38s system 51% cpu 18:47:39.54 total


    % git-annex info
    repository mode: direct
    trusted repositories: 0
    semitrusted repositories: 4
    	00000000-0000-0000-0000-000000000001 -- web
     	00000000-0000-0000-0000-000000000002 -- bittorrent
     	069de9a2-dc53-4c0a-82e0-a61a1f29e6b3 -- stratos PC [stratos]
     	49b5b3a4-56ac-4cf2-aed9-1c23d3181c97 -- Toshiba USB HDD [here]
    untrusted repositories: 0
    transfers in progress: none
    available local disk space: 120.41 gigabytes (+1 megabyte reserved)
    local annex keys: 6303
    local annex size: 1.87 terabytes
    annexed files in working tree: 7412
    size of annexed files in working tree: 2.24 terabytes
    bloom filter size: 32 mebibytes (1.3% full)
    backend usage: 
    	SHA256E: 7412


    % git-annex version
    git-annex version: 6.20160613-g1e4e6f4
    build flags: Assistant Webapp Pairing Testsuite S3(multipartupload)(storageclasses) WebDAV Inotify DBus DesktopNotify XMPP ConcurrentOutput TorrentParser MagicMime Feeds Quvi
    key/value backends: SHA256E SHA256 SHA512E SHA512 SHA224E SHA224 SHA384E SHA384 SHA3_256E SHA3_256 SHA3_512E SHA3_512 SHA3_224E SHA3_224 SHA3_384E SHA3_384 SKEIN256E SKEIN256 SKEIN512E SKEIN512 SHA1E SHA1 MD5E MD5 WORM URL
    remote types: git gcrypt S3 bup directory rsync web bittorrent webdav tahoe glacier ddar hook external
    local repository version: 5
    supported repository versions: 5 6
    upgrade supported from repository versions: 0 1 2 3 4 5
    operating system: linux x86_64

Thank you for your time.
