Particle Hunter

Restore deleted files from lxplus

Earlier today I was trying to connect my VScode to lxplus and I was unable. I was trying to connect to particular working folder but it seems that vscode can’t find this folder. This was strange so I opened my terminal and then sshed to lxplus. I was surprised to find that this folder on my work directory is not there. This was annoying as it contains some MC files I generated locally which took somedays (as I still early in my analysis and don’t have a GRID ready analysis). The idea of having of having to generate all of them again was not good by any mean. I don’t have time for that. Beside in the process of generating them I was very annoying for CERN as I got many warning emails from CERN about my high memory usage (yes Gauss is a RAM monester). The source code for Gauss-job and analysis scripts weren’t a problem as I always have them pushed to a git repository on my github account. So I was able to recover them from there. But the MC files were a problem.

Now I was hoping there was a way to restore the deleted files. I went to Twiki and looked for a solution and found an article that describes the process. I was happy for know that all afs is being backuped regularly. Also they backup personal home and work spaces for each user. There is a difference however between both of them as the files stored in home and deleted are cached and you don’t need to get them from tape. Anyway it was good to know that home directory is backed each night (CERN time) and cached inside /afs/* where I could easily find the deleted files (up to 24 hours) beside other files. But actually my MC files were on work directory which is not cached. The backup are actually on tape which is slow to restore and process it a little bit more involved than just move the files back.

To store the files, the first was to create an empty folder with the following

afs_admin recover /afs/<path_to_my_missing_files>

The output asked me what backup I would like to recover. I chosed the latest one and then it will take sometime (long time) to restore the files. The backup will be written to a temporary folder and then you need to move the files to the correct location. The output will give you the path to the temporary folder. I then moved the files to the correct location.

This was my first day after the new year holiday and I was feeling horrible that I had this issue. I don’t recall what happened last week that could lead to this but anyway I was happy that everything worked out and now I can continue struggling with my analysis.

#Linux #lxplus #CERN #Servers