When I try and run 'gulp watch' I get this error:

[09:34:18] Using gulpfile /var/www/resources/mym/gulpfile.js
[09:34:18] Starting 'watch'...
[09:34:18] 'watch' errored after 4.82 ms
[09:34:18] Error: watch ENOSPC
    at errnoException (fs.js:1031:11)
    at FSWatcher.start (fs.js:1063:11)
    at Object.fs.watch (fs.js:1088:11)
    at Gaze._watchDir (/var/www/resources/mym/node_modules/gulp/node_modules/vinyl-fs/node_modules/glob-watcher/node_modules/gaze/lib/gaze.js:289:30)
    at /var/www/resources/mym/node_modules/gulp/node_modules/vinyl-fs/node_modules/glob-watcher/node_modules/gaze/lib/gaze.js:358:10
    at iterate (/var/www/resources/mym/node_modules/gulp/node_modules/vinyl-fs/node_modules/glob-watcher/node_modules/gaze/lib/helper.js:52:5)
    at Object.forEachSeries (/var/www/resources/mym/node_modules/gulp/node_modules/vinyl-fs/node_modules/glob-watcher/node_modules/gaze/lib/helper.js:66:3)
    at Gaze._initWatched (/var/www/resources/mym/node_modules/gulp/node_modules/vinyl-fs/node_modules/glob-watcher/node_modules/gaze/lib/gaze.js:354:10)
    at Gaze.add (/var/www/resources/mym/node_modules/gulp/node_modules/vinyl-fs/node_modules/glob-watcher/node_modules/gaze/lib/gaze.js:177:8)
    at new Gaze (/var/www/resources/mym/node_modules/gulp/node_modules/vinyl-fs/node_modules/glob-watcher/node_modules/gaze/lib/gaze.js:74:10)

but if I just run 'gulp' then everything runs perfectly.. Any ideas?