[comp.sys.apollo] Tar Backups

danny@idacom.uucp (Danny Wilson) (01/18/90)

> lampi@pnet02.gryphon.com (Michael Lampi) writes in <24648@gryphon.COM> :
> [...]
> If you like tar for backups there is no reason it can not be used for such.
>

There is a big problem with tar for doing backups if your backup
spans multiple tapes.  This is not a particular problem with Apollo,
just tar in general.

This means that, for example, you want to backup a 10 Meg directory
and only have 5 Meg tape, tar will only backup half the directory!

It does not prompt for a second tape and will not inform you that
data was not recorded.

-- 
Danny Wilson			danny@idacom.uucp
IDACOM Electronics		alberta!idacom!danny
Edmonton, Alberta	X.400	danny@idacom.cs.ubc.cdn	
C A N A D A		Voice	+1 403 462 4545

tim@gvlf9-e.gvl.unisys.com (Timothy Scharping) (01/18/90)

In article <1990Jan17.185931.21912@idacom.uucp> danny@idacom.uucp (Danny Wilson) writes:
>
>There is a big problem with tar for doing backups if your backup
>spans multiple tapes.  This is not a particular problem with Apollo,
>just tar in general.
>
>This means that, for example, you want to backup a 10 Meg directory
>and only have 5 Meg tape, tar will only backup half the directory!
>
>It does not prompt for a second tape and will not inform you that
>data was not recorded.
>

	I have also encountered another problem with using tar for complete
system backups.  There seem to be several files which tar isn't able to read
(i.e. `node_data/system_logs/sys_error_log).  When tar is comes accross a file
that can't be opened it chokes causing it to hang on our DN3550.

--tim
++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
Timothy Scharping       Internet: tim@GVL.Unisys.COM
Unisys Corporation	UUCP: ...!uunet!lgnp1!gvlv2!tim  
Paoli, PA  19301              ...!{gatech,purdue}!psuvax1!burdvax!gvlv2!tim

lampi@pnet02.gryphon.com (Michael Lampi) (01/19/90)

danny@idacom.uucp (Danny Wilson) writes:
>
>
>> lampi@pnet02.gryphon.com (Michael Lampi) writes in <24648@gryphon.COM> :
>> [...]
>> If you like tar for backups there is no reason it can not be used for such.
>>
>
>There is a big problem with tar for doing backups if your backup
>spans multiple tapes.  This is not a particular problem with Apollo,
>just tar in general.
>
>This means that, for example, you want to backup a 10 Meg directory
>and only have 5 Meg tape, tar will only backup half the directory!
>
>It does not prompt for a second tape and will not inform you that
>data was not recorded.
>
>-- 
>Danny Wilson			danny@idacom.uucp
>IDACOM Electronics		alberta!idacom!danny
>Edmonton, Alberta	X.400	danny@idacom.cs.ubc.cdn	
>C A N A D A		Voice	+1 403 462 4545


But if you want to use tar for backups, go right ahead!

(I didn't say you HAD to use tar -- just like I wouldn't say you should use
floppies, either. It all depends on what you're trying to do and what you are
comfortable with.  :-)  )

Personally, I use cpt to floppies for small stuff, and wbak to 1/2 inch
magtape for full backups.

Michael Lampi               MDL Corporation   213/782-7888   fax 213/782-7927

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"My opinions are that of my corporation!"