Ergon: File duplication on different tapes - mfdupli

The mfdupli command allows obtaining a file copy with the guarantee that it will be migrated to a different tape from that which stores the original file. The principal objective is to protect especially valuable files from an accidental deletion (unintentional rm). A second objective is to protect your data from any possible damage to the cassette (or its tape) which stores up to 6TB or an average of 100,000 files. Files considered especially valuable are those whose contents would be very costly to recalculate (in human time or calculation hours), or for which this could become impossible (libraries, obsolete compiler versions or even machines which are not longer available).

The duplicated file has the same characteristics as the original:

  • Lifespan of one year.
  • Size is included in the quotas.
  • Managed by using the classic UNIX commands.
  • It is stongly recommended that the original file and the copy remain identical: If the original file is changed (renamed, modified, deleted or the expiration date is changed), the copy should be updated at the same time.

The mfdupli command can be regarded as a simple cp which assures that the copy will be located on a different tape than the original file.

The mfdupli command has the following characteristics:

  • Asynchronous: The copy is not actually made until some hours later.
  • The file copies are located in the DUPLI directory (called $HOME/DUPLI) in order to distinguish them from the originals.
  • It cannot overwrite files with the same name which already exist in DUPLI.

Using the mfdupli command from Ergon

# Duplication of a file
ergon-rlab001 : mfdupli fic fic
+ dupli /arch/home/rech/lab/rlab001/fic /linkhome/rech/lab/rlab001/DUPLI/fic 
+++ 1 duplications ; 0 entrees dupli existantes ; 1 mkdir +++

# Duplication of a file tree
ergon-rlab001 : mfdupli -r rep rep
+ dupli /arch/home/rech/lab/rlab001/rep//fic1 /linkhome/rech/lab/rlab001/DUPLI/rep//fic1
+++ 1 duplications ; 0 entrees dupli existantes ; 2 mkdir +++

# List of duplications in process
ergon-rlab001 : mfdupli -l
/linkhome/rech/lab/rlab001/DUPLI/copie -> /arch/home/rech/lab/rlab001/original

Using the mfdupli command from Adapp

# The following **must** be done before using the mfdupli command
adapp-rlab001 : cd $ARCHIVE
adapp-rlab001 : pwd
/arch/home/rech/lab/rlab001

# Duplication of a file
adapp-rlab001 : mfdupli fic fic
+ dupli /arch/home/rech/lab/rlab001/fic /arch/home/rech/lab/rlab001/DUPLI/fic 
+++ 1 duplications ; 0 entrees dupli existantes ; 1 mkdir +++

# Duplication of a file tree
ergon-rlab001 : mfdupli -r rep rep
+ dupli /arch/home/rech/lab/rlab001/rep//fic1 /arch/home/rech/lab/rlab001/DUPLI/rep/fic1
+++ 1 duplications ; 0 entrees dupli existantes ; 2 mkdir +++

# List of duplications in process
ergon-rlab001 : mfdupli -l
/arch/home/rech/lab/rlab001/DUPLI/copie -> /arch/home/rech/lab/rlab001/original