Wayne State University

AIM HIGHER

Wayne State University

High Performance Computing Services

Snapshots

HOW TO RETREIVE FILES FROM THE PNFS SNAPSHOT

Follow these steps to recover files using your PNFS snapshot.
Logon on to the Grid.

In this example there is a directory that was accidentally deleted called namd_test2014. Example:

ls -1


Input: ls -1

We do not see that directory in the home directory.

Output:  Line 1: bio, Line 2: mpi_hello_world.c

The snapshots are found on the volumes found in /wsu/home/. The directory after that corresponds to the first two letters of one's Access ID. Within that directory is the ".snapshot" directory. For example:

cd /wsu/home/zz/.snapshot

Input: cd /wsu/home/zz/.snapshot

List the contents of the directory. Example

ls -1

Input: ls -1

In the example shown seven days worth of snapshots are listed.

Output: Line 1: 2014.10.02.03.00.01.daily, Line 2: 2014.10.03.03.00.02.daily, Line 3: 2014.10.04.03.00.02.daily, Line 4: 2014.10.05.03.00.01.daily, Line 5: 2014.10.06.03.00.02.daily, Line 6: 2014.10.07.03.00.02.daily, Line 7: 2014.10.08.03.00.01.daily

We will see if the latest snapshot has the deleted file that we want to restore. Example:

cd 2014.10.08.03.00.01.daily

Input: cd 2014.10.08.03.00.01.daily

Complete the directory by typing in the first four characters of your Access ID, followed by a forward slash then your complete Access ID. Input: cd 2014.10.08.03.00.01.daily/zz99/zz9993

List the items in the directory. Example:

ls -1

Input: ls -1

The directory that we want to restore, namd_test2014, is in this snapshot.

Output: Line 1: bio, Line 2: mpi_hello_world.c, Line 3: namd_test2014

Copy the files to your home directory. Example:

cp -r namd_test2014/ ~

Input: cp -r namd_test2014/ ~

Go to your home directory

Input: cd ~

List the contents to make sure that the file is there. ' ls -1'

Input: cd ~

Your file has been restored.

Output: Line 1: bio, Line 2: mpi_hello_world.c, Line 3: namd_test2014
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