IPython error

gistfile1.txt

[I 11:41:27.812 NotebookApp] Using existing profile dir: u''
[I 11:41:27.818 NotebookApp] Using MathJax: 
[I 11:41:27.846 NotebookApp] Serving notebooks from local directory: 
[I 11:41:27.846 NotebookApp] 0 active kernels 
[I 11:41:27.846 NotebookApp] The IPython Notebook is running at: https://[all ip addresses on your system]:9999/
[I 11:41:27.846 NotebookApp] Use Control-C to stop this server and shut down all kernels (twice to skip confirmation).
[I 11:41:36.389 NotebookApp] 302 GET / () 0.67ms
[I 11:41:40.188 NotebookApp] Creating new notebook in 
[E 11:41:40.199 NotebookApp] Error while saving file: Untitled.ipynb disk I/O error
    Traceback (most recent call last):
      File "/scratch/gaa/local/src/anaconda/lib/python2.7/site-packages/IPython/html/services/contents/filemanager.py", line 383, in save
        self.check_and_sign(nb, path)
      File "/scratch/gaa/local/src/anaconda/lib/python2.7/site-packages/IPython/html/services/contents/manager.py", line 428, in check_and_sign
        self.notary.sign(nb)
      File "/scratch/gaa/local/src/anaconda/lib/python2.7/site-packages/IPython/nbformat/sign.py", line 248, in sign
        self.store_signature(signature, nb)
      File "/scratch/gaa/local/src/anaconda/lib/python2.7/site-packages/IPython/nbformat/sign.py", line 251, in store_signature
        if self.db is None:
      File "/scratch/gaa/local/src/anaconda/lib/python2.7/site-packages/IPython/utils/traitlets.py", line 412, in __get__
        value = method()
      File "/scratch/gaa/local/src/anaconda/lib/python2.7/site-packages/IPython/nbformat/sign.py", line 129, in _db_default
        self.init_db(db)
      File "/scratch/gaa/local/src/anaconda/lib/python2.7/site-packages/IPython/nbformat/sign.py", line 141, in init_db
        )""")
    OperationalError: disk I/O error
[W 11:41:40.203 NotebookApp] Unexpected error while saving file: Untitled.ipynb disk I/O error
[E 11:41:40.204 NotebookApp] {
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      "Accept-Language": "en-US,en;q=0.5", 
      "Accept-Encoding": "gzip, deflate", 
      "Cache-Control": "no-cache", 
      "Connection": "keep-alive", 
      "Accept": "application/json, text/javascript, */*; q=0.01", 
      "User-Agent": "Mozilla/5.0 (X11; Ubuntu; Linux x86_64; rv:37.0) Gecko/20100101 Firefox/37.0", 
      "Host": ":9999", 
      "X-Requested-With": "XMLHttpRequest", 
      "Pragma": "no-cache", 
      "Cookie": "__utma=170659492.1716016652.1397056628.1429609178.1430149129.3; _ga=GA1.2.1716016652.1397056628; username-radio-ccc-uam-es-9999=\"2|1:0|10:1428429582|30:username-radio-ccc-uam-es-9999|48:ODJlYjgyMmQtMDQwNy00MWY5LWI0NTItMGU3NmNhYTZmNWNh|72b21758fcd382eee1b579b393b92d2a64b81e5c8f1a4a187db30154b09f9d28\"; __utmz=170659492.1430149129.3.2.utmcsr=google|utmccn=(organic)|utmcmd=organic|utmctr=(not%20provided)", 
      "Referer": ":9999/tree", 
      "Content-Type": "application/x-www-form-urlencoded; charset=UTF-8"
    }
[E 11:41:40.205 NotebookApp] 500 POST /api/contents () 17.31ms referer=:9999/tree