Error after running gulp serve

After runnig **gulp serve** i got this error:

[20:40:07] Using gulpfile /var/www/html/blur-admin/gulpfile.js
[20:40:07] Starting 'scripts'...
[20:40:07] Starting 'styles'...
[20:40:08] Starting 'stylesAuth'...
[20:40:08] Starting 'styles404'...
[20:40:08] Starting 'copyVendorImages'...
[20:40:10] Finished 'stylesAuth' after 2.23 s
[20:40:10] Starting 'injectAuth'...
[20:40:10] Finished 'styles404' after 2.23 s
[20:40:10] Starting 'inject404'...
[20:40:10] gulp-inject 1 files into auth.html.
[20:40:10] gulp-inject 1 files into 404.html.
[20:40:10] gulp-inject 1 files into reg.html.
[20:40:10] Finished 'inject404' after 164 ms
[20:40:10] Finished 'injectAuth' after 180 ms
[20:40:10] gulp-inject 52 files into main.scss.
[20:40:10] Finished 'styles' after 3.16 s
[20:40:11] Finished 'copyVendorImages' after 3.36 s
[20:40:11] all files 244.11 kB
[20:40:11] Finished 'scripts' after 3.7 s
[20:40:11] Starting 'inject'...
[20:40:11] gulp-inject 1 files into index.html.
[20:40:11] gulp-inject 139 files into index.html.
[20:40:11] Finished 'inject' after 124 ms
[20:40:11] Starting 'watch'...
[20:40:11] 'watch' errored after 11 ms
[20:40:11] Error: watch /var/www/html/blur-admin/ ENOSPC
at exports._errnoException (util.js:1018:11)
at FSWatcher.start (fs.js:1443:19)
at Object.fs.watch (fs.js:1470:11)
at Gaze._watchDir (/var/www/html/blur-admin/node_modules/gaze/lib/gaze.js:289:30)
at /var/www/html/blur-admin/node_modules/gaze/lib/gaze.js:358:10
at iterate (/var/www/html/blur-admin/node_modules/gaze/lib/helper.js:52:5)
at /var/www/html/blur-admin/node_modules/gaze/lib/helper.js:61:11
at /var/www/html/blur-admin/node_modules/gaze/lib/gaze.js:420:5
at iterate (/var/www/html/blur-admin/node_modules/gaze/lib/helper.js:52:5)
at Object.forEachSeries (/var/www/html/blur-admin/node_modules/gaze/lib/helper.js:66:3)

In fact, it works for me fine for the first time and now only **gulp serve:dist** works fine.
Any idea about this error?
BTW my work environment is Ubuntu 14.04