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Conference cookie::archive_backup

Title:Archive/Backup
Moderator:COOKIE::MHUAIG
Created:Wed Sep 08 1993
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:479
Total number of notes:2283

439.0. "INCREMENTAL backups of WNT and UNIX clients ?" by ATZIS1::KARTNER_M (HOUSTON, we have a problem) Mon Apr 21 1997 10:21

    Hi!
    
    I've got a question concerning INCREMENTAL backups of WNT and
    UNIX clients
    
    
    WNT:
    
    	How are incremental backups handled? 
    		- Are they working with the WNT Archive bit? 
    		- May I issue a backup for files specified by 
    		  modification/creation time too ? 
    		- May I control if my save request sets the ARCHIVE 
    		  bit after backing up a file or leaving it unchanged?
    
    UNIX:
    	How are incremental backups handled?
    		Standard TAR doesn't work with modification times. Is it
    		possible to select a creation/modification time as
    		parameter for the ABSgtar?
    		Or are incremental backups unsupported for unix ?
    		
    						thanks
    						Michael (a VMS guy) 
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439.1AnswersCOOKIE::MHUAMon Apr 21 1997 15:5049
    
    For both NT and UNIX, we use Gnutar as backup utility.  The function of
    Gnutar on both platform are identical.  (with few minor exceptions,
    but the difference will not be noticed at the user level.)

    About NT :

>Are they working with the WNT Archive bit?
    We do not do anything with WNT archive bit.

>May I issue a backup for files specified by modification/creation time too
    It is possible to do so, but ABS does not recommend the users to handle
    incremental date specification, because it's a lot of work for the
    users to control it.  If you let ABS handle FULL/incremental scheduling
    and which files are to be in incremental, the operation will be
    automatic.  The best thing is to specify FULL data movement type and
    use one of our complex schedules (such as weekly full daily
    incremental).

    If you want to specify yourself files with modification/creation time
    manually, you have to do a lot of work that ABS does it for you.

>May I control if my save request sets the ARCHIVE
>bit after backing up a file or leaving it unchanged?
    ABS does not care what you do with archive bit.
    	
    About UNIX backup  - we do not use standard TAR.  We user Gnutar which
    has incremental capability.  For both NT and UNIX, incremental is done
    as follows ( suppose we use weekly FULL and daily incremental):
    Please look into ABS documentation for the incremental levels of ABS.

    FULL backup is performed on Sunday for /usr/users/smith/
       (backup date "20-apr-1997 00:00")

    Level 1 incremental is performed, and ABS figures out that the last
    backup was performed at "20-apr-1997 00:00" and it issues a Gnutar
    command to backup files created/modified after "20-apr-1997 00:00".
       (backup date "21-apr-1997 00:00")

    Level 2 incremental is performed, and ABS figures out that the last
    backup was performed at "21-apr-1997 00:00" and it issues a Gnutar
    command to backup files created/modified after "21-apr-1997 00:00".
           (backup date "22-apr-1997 00:00") 

    ABS's incremental level can go up to level 6 on Saturday, then it goes 
    back to do FULL on Sunday for weekly full and daily incremental
    scheduling.

                                                  Masami
439.2thanks !!ATZIS1::KARTNER_MHOUSTON, we have a problemTue Apr 22 1997 04:254
    Hi!
    
    	Thanks for your helpfull answer
    								Michael