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....
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6 replies Latest Post - 2013-02-07T08:47:55Z by Lumart
Pinned topic Best tools to perform a backup under Windows
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Updated on 2013-02-07T08:47:55Z at 2013-02-07T08:47:55Z by Lumart
Re: Best tools to perform a backup under Windows2013-01-28T09:33:39Z in response to LumartAccording 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.
GKellner 11000079SA237 PostsACCEPTED ANSWER
Re: Best tools to perform a backup under Windows2013-02-05T08:01:11Z in response to LumartRegarding 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.
Re: Best tools to perform a backup under Windows2013-02-05T09:00:43Z in response to GKellnerI 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 11000079SA237 PostsACCEPTED ANSWER
Re: Best tools to perform a backup under Windows2013-02-05T09:49:39Z in response to LumartDowntime 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.
Re: Best tools to perform a backup under Windows2013-02-07T08:47:55Z in response to GKellnerWe 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).
brcowan 2000005CYP661 PostsACCEPTED ANSWER
Re: Best tools to perform a backup under Windows2013-01-30T16:19:53Z in response to LumartFor 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...
Advisory Software Engineer
ClearCase Software Advisory Team (SWAT)
IBM Software Group
550 King St
Littleton, MA 01460