Topic
  • 6 replies
  • Latest Post - ‏2013-02-07T08:47:55Z by Lumart
Lumart
Lumart
114 Posts

Pinned topic Best tools to perform a backup under Windows

‏2013-01-24T16:33:49Z |
What are the best tools to perform a backup of Vobs under Windows?
I mean, to compress and save Vob storages in a remote folder.
I was considering Robocopy, 7zip, the Windows Backup Tool....
Any suggestion?
Updated on 2013-02-07T08:47:55Z at 2013-02-07T08:47:55Z by Lumart
  • Lumart
    Lumart
    114 Posts

    Re: Best tools to perform a backup under Windows

    ‏2013-01-28T09:33:39Z  
    According to the CC manuals, under Windows xcopy is best tool to copy the VOB storages on a backup location.
    But what is the best tool to compress (i.e. zip) them?
    Of course, time is an important issue.
    We want to minimize the total backup elapsed time, so we are looking for tool that perform the copy and zip operations as quickly as possible.
  • brcowan
    brcowan
    748 Posts

    Re: Best tools to perform a backup under Windows

    ‏2013-01-30T16:19:53Z  
    For various reasons, IBM doesn't recommend a particular software package for backing up ClearCase data on Windows.

    On windows, if you want to be able to back up your VOBs without taking Clearcase down, your backup package needs to be able to:
    1) copy files that are open for write access
    2) back up the ACLs in the exact order that they are specified

    xcopy generally gets the second right, but misses the boat on the first.
    robocopy gets the first (in some versions) and occasionally misses the boat on the second.
    Windows Volume Shadow Copy? If ClearCase is up during the snapshot, well.. bad things will happen.

    If you don't mind stopping ClearCase, then any of the tools you mentioned will do a good job of copying the data and (mostly) the ACLs.

    However, the key phase of a backup is not the backup, it's the restore. Whatever backup method you decide to try out first, you need to test a restore and verify that the data and ACLs were saved correctly. To do that, you would restore the VOB to a different host that is set up as it's own registry server and has the default MultiSite jobs DISABLED (in the even that the VOB you're working with is replicated). Once the VOb is restored:
    • register and tag the VOB. If this step fails, check the "db" log to see if it complains about "unknown style protections." If so, the VOB acls were damaged during the backup or restore. If you get other errors, those need to be investigate sseparately
    • mount the VOB, create a view, and verify that the VOB owner and/or ClearCase admin user can access files.
    • log out as the user who performed the restore, and back in as a normal one.
    • Create a view, mount the VOB, and verify that a normal user can access files, check them in and out, etc.

    Once you have a good backup/restore process, please don't forget to regularly test the restore. Not all backup logs tell you when something subtle goes wrong.

    You do not want to find out the hard way that your backup/restore hasn't been working for over a month... Because that's usually because you called us about a corrupt database after a disk crash and have been told that the database can't be repaired...

    =================================================================
    Brian Cowan
    Advisory Software Engineer
    ClearCase Software Advisory Team (SWAT)
    Rational Software
    IBM Software Group
    550 King St
    Littleton, MA 01460

    Phone: 1.978.899.5436
    Web: http://www.ibm.com/software/rational/support/
  • GKellner
    GKellner
    259 Posts

    Re: Best tools to perform a backup under Windows

    ‏2013-02-05T08:01:11Z  
    • Lumart
    • ‏2013-01-28T09:33:39Z
    According to the CC manuals, under Windows xcopy is best tool to copy the VOB storages on a backup location.
    But what is the best tool to compress (i.e. zip) them?
    Of course, time is an important issue.
    We want to minimize the total backup elapsed time, so we are looking for tool that perform the copy and zip operations as quickly as possible.
    Regarding compression:
    ClearCase saves all elements except text_file as compressed containers.
    So you should do some analyse work to check, if compressing the backup make sense.

    Our procedure is:
    • lock all VOBs
    • create a snapshot using Shadow Copy
    • unlock all VOBs
    • copy the snapshot to the backup device

    This is managed by Legato Network with some homegrown scripts regarding the lock/unlock.

    greetings georg.
  • Lumart
    Lumart
    114 Posts

    Re: Best tools to perform a backup under Windows

    ‏2013-02-05T09:00:43Z  
    • GKellner
    • ‏2013-02-05T08:01:11Z
    Regarding compression:
    ClearCase saves all elements except text_file as compressed containers.
    So you should do some analyse work to check, if compressing the backup make sense.

    Our procedure is:
    • lock all VOBs
    • create a snapshot using Shadow Copy
    • unlock all VOBs
    • copy the snapshot to the backup device

    This is managed by Legato Network with some homegrown scripts regarding the lock/unlock.

    greetings georg.
    I intend to follow this procedure:

    1) lock all Vobs
    2) stop ClearCase
    3) tar any Vob (just tar, not zip, in order to reduce the elapsed time)
    4) transfer the tars to the backup storage
    5) start ClearCase
    6) unlock the Vobs

    For step 3 I would use the GNU tar port for Windows, for step 4 Robocopy.
    Does anybody see any risk in this procedure?
  • GKellner
    GKellner
    259 Posts

    Re: Best tools to perform a backup under Windows

    ‏2013-02-05T09:49:39Z  
    • Lumart
    • ‏2013-02-05T09:00:43Z
    I intend to follow this procedure:

    1) lock all Vobs
    2) stop ClearCase
    3) tar any Vob (just tar, not zip, in order to reduce the elapsed time)
    4) transfer the tars to the backup storage
    5) start ClearCase
    6) unlock the Vobs

    For step 3 I would use the GNU tar port for Windows, for step 4 Robocopy.
    Does anybody see any risk in this procedure?
    Downtime might be the risk.

    To tar the VOBs can take hours, where no one can access the files in ClearCase.
    Nightly builds or other scheduled jobs might run into the daily buisness, which can reduce performance for the developers.

    Another point is the scrubber for the cleartext.
    We had some tar procedures years ago.
    The tar changed the last access time for the files, so the cleartext pool never got scrubbed.
    This will reduce the free disk space and of course the backups will crow.
    You could run the scrubber with aggressive parameters, but this will reduce the perfrmance for developers, because the files aren't cached long enough.

    greetings georg.
  • Lumart
    Lumart
    114 Posts

    Re: Best tools to perform a backup under Windows

    ‏2013-02-07T08:47:55Z  
    • GKellner
    • ‏2013-02-05T09:49:39Z
    Downtime might be the risk.

    To tar the VOBs can take hours, where no one can access the files in ClearCase.
    Nightly builds or other scheduled jobs might run into the daily buisness, which can reduce performance for the developers.

    Another point is the scrubber for the cleartext.
    We had some tar procedures years ago.
    The tar changed the last access time for the files, so the cleartext pool never got scrubbed.
    This will reduce the free disk space and of course the backups will crow.
    You could run the scrubber with aggressive parameters, but this will reduce the perfrmance for developers, because the files aren't cached long enough.

    greetings georg.
    We resolved to compress the .vbs with 7zip and then to copy them in a remote storage with robocopy.
    There is an issue with ACLs (7zip does not preserver them), but we solved it by saving ACLs before the compression with icacls and then restore them.
    In order to minimize the elapsed time, we check the Vobs history: if a Vob has not been modified since the previous backup, we don't backup it (actually, we keep the previous backup).