Introduction of ENCS on-line backup system

All users of ENCS's computing resources can access on-line backup system, which creates 'snapshots' (read-only copies of your files) at regular intervals. Under Unix, every directory mounted from Netapp has a .snapshot subdirectory with a number of entries. The .snapshot directory doesn't appear in the output of ls unless you specify it explicitly. You can recover files that have been deleted or changed by copying files from the snapshot to your home directory.

[respect] [/home/u/username] > ls -la .snapshot
total 3088
drwx------ 58 username username 53248 Sep 27 17:03 hourly.0
drwx------ 58 username username 53248 Sep 27 17:03 hourly.1
....
drwx------ 57 username username 53248 Sep 23 17:24 hourly.27
drwx------ 57 username username 53248 Sep 23 17:24 nightly.0
drwx------ 57 username username 53248 Sep 23 17:24 nightly.1
....
drwx------ 59 username username 53248 Sep 13 22:21 nightly.11
drwx------ 57 username username 53248 Sep 23 17:24 weekly.0
drwx------ 58 username username 53248 Sep 17 17:47 weekly.1
....
drwx------ 59 username username 24576 Jun 6 23:23 weekly.16


The timestamps you see do not reflect the date and time that the snapshot was made. To see the real schedule of snapshots type cat /mnt/nettemp/snapshot.txt

[respect] [/home/u/username] > cat /mnt/nettemp/snapshot.txt
date           name
--------    --------
Sep 27 07:00 hourly.0
Sep 27 06:00 hourly.1
....
Sep 26 03:00 hourly.27
Sep 26 00:00 nightly.0
Sep 25 00:00 nightly.1
....
Sep 14 00:00 nightly.11
Sep 27 00:00 weekly.0
Sep 20 00:00 weekly.1
....
Jun 07 00:00 weekly.16


Recover a file

You need to know:

• The name of the file.
• where was the file (the path).

To recover a lost file:

• find all available versions (timestamp) of your lost file in .snapshot subfolder.
• select the proper version of the file to be recovered, and copy it to an appropriate target directory.

Recover a file from Windows:

AN EXAMPLE: (a file called tempfile.txt was deleted in your unix home directory U:\ )

To recover a lost file, Here is the procedure:

1. Double-click on "My Computer" icon on your desktop

2. In the address bar, just type in: U:\.snapshot ( or U:\~snapshot )

Note: If the file was saved in your windows home directory, just change the letter U:\ as G:\ .

3. Click "Search" in the tool bar.

4. Click "All files and folders", In the All or part of the file name field, type the name of the file you want to search for: tempfile.txt, then click "Search" button.

5. Your search results will display on the right side of the Search Results window, select one version of the file to be recovered, and copy it back to your unix home directory U:\.

Recover a file from Linux/Unix:

AN EXAMPLE:    (a file called tempfile.txt was deleted in your unix home directory /home/u/username)

To recover a lost file, here is the procedure:

1. At your UNIX prompt please type:
ls -la /home/u/username/.snapshot/*/tempfile.txt

NOTES:

• If you don't remember which sub directory the file was saved, please type:
          find /home/u/username/.snapshot/*/ -name tempfile.txt -exec ls -la {} \;
• Do not actually type /home/u/username. "u" is the first letter of your username, so for user j_smith:
  ls -la /home/j/j_smith/.snapshot/*/tempfile.txt

Now you get all available versions of your lost file listed in .snapshot subfolder.

-rwx------ 1 username 22 Jun 28 16:24 /home/u/username/.snapshot/hourly.0/tempfile.txt
-rwx------ 1 username 22 Jun 28 16:24 /home/u/username/.snapshot/hourly.1/tempfile.txt
....
-rwx------ 1 username 22 Jun 28 16:24 /home/u/username/.snapshot/hourly.27/tempfile.txt
-rwx------ 1 username 22 Jun 28 16:24 /home/u/username/.snapshot/nightly.0/tempfile.txt
-rwx------ 1 username 22 Jun 28 16:24 /home/u/username/.snapshot/nightly.1/tempfile.txt
....
-rwx------ 1 username 22 Jun 28 16:24 /home/u/username/.snapshot/nightly.11/tempfile.txt
-rwx------ 1 username 22 Jun 28 16:24 /home/u/username/.snapshot/weekly.0/tempfile.txt
-rwx------ 1 username 22 Jun 28 16:24 /home/u/username/.snapshot/weekly.1/tempfile.txt
....
-rw------- 1 username 13 May 18 11:16 /home/l/leonlg/.snapshot/weekly.16/tempfile.txt


2. select one version of the file to be recovered, and copy it to an appropriate target directory.
cp /home/u/username/.snapshot/hourly.0/tempfile.txt /home/u/username/