Greetings,

    Over the weekend I was attempting to install a new harddrive on one of 
    the computers in our SGI NIS cluster.
    Unfortunately, an existing drive (w/ lots of data on it) was 
    inadvertantly damaged.

    This is somewhat of a disaster, although its not as bad as it could 
    have been as much of the data had been backed up to
    a DLT tape.  Data collected since the backup was for the most part 
    still stored on the spectrometers.

    There are in all "bad" things lessons to be learned.    As I mentioned 
    previously, we now have an automated backup system that runs once weekly for

    each data disk and which 
    creates a mirror copy of the disk at the time of the backup.  This 
    system **failed** in the present case because of a slight typo that I 
    had made in setting up a directory for the disk in question (this was 
    particularly unfortunate as backups
    had been performed correctly for ALL other disk drives).

    The specific recommedations I would be make to users to ensure data 
    integrity are as follows:

    
    -periodically create a backup of your current disk contents on DLT tape 
    (owing to the high capacity of the tapes, it should be
    possible to copy the entire contents of any ones persons disk to a 
    single tape (takes about one hour for 40 Gbyte of data).  If you are 
    not sure
    how to use the drive, visit 
   http://instinct.v24.uthscsa.edu/~hincklab/soft/tape.shtml.  Cindy has 
    extra tapes - just talk to her if you are in need.

   
    -periodically check to ensure that there is a mirror of your current 
    data on the backup system.  To do this, simply cd to /inert1.  There 
    you should find a directory corresponding to the name of the disk that 
    contains your data.  Change into the subdirectory (cd /inert1/my_disk) 
    corresponding to your disk and make sure that files you have recently 
    written are there.  Depending on the day of the week and the day of the 
    scheduled backup for your disk,
    you should find all files except for those written since the last 
    backup.
    
    disk        backup_day (2:00AM)

    
    /inept1     mon
    /inept2     mon 

    These are all "server" files on instinct:

    /u          sat
    /usr/freeware       sat
    /usr/local  sat
    /disk1      sat

    
    /avance5001 sun
    /avance5002 sun
    /u on avance500     sun
    /avance6001 sun
    /u on avance600     sun
    /avance7001 sun
    /u on avance700     sun

    
    /bioc071    thurs
    /bioc011    thurs
    /nmrfac1    thurs  

    /instinct1  tues
    /instinct2  tues

    /nall1      wed
    /nall2      wed

    
    Finally, please be aware that the backup system is not archival in 
   nature.  That is, if you delete a file from your data disk, that file 
    will also be deleted from the backup system (at least within the time 
    of the next backup - that is within a week).  Thus, if you are going to 
    delete data permanently from one of your data disks, be certain that 
    you have a copy saved on DLT tape (my recommendation is that users have 
    two, or more tapes - one for a "current" backup, and one or more for 
    archival backups).

   
    Andy