Re: [Hampshire] Tar file max size

Top Page
Author: Brad Macpherson via Hampshire
Date:  
To: hampshire
CC: Brad Macpherson
Subject: Re: [Hampshire] Tar file max size

Reply to this message
gpg: failed to create temporary file '/var/lib/lurker/.#lk0x57ff2100.hantslug.org.uk.23097': Permission denied
gpg: keyblock resource '/var/lib/lurker/pubring.gpg': Permission denied
gpg: Signature made Wed Mar 26 16:29:23 2025 GMT
gpg: using RSA key 898A78DCF0DC9B14FF90997EB472A863FC94FD2A
gpg: Can't check signature: No public key

On 26/03/2025 12:04, rmluglist2--- via Hampshire wrote:
> Hi all
>
> Coming back to a topic I raised a few months ago…
>
> I’ve been trying to get a write-once-read-many backup using tape.
> Trouble is – it keeps failing.   It’s a fair old amount of data to
> backup (20+Tb) but I think one of the issues is I’m trying:
>
> tar czvf /dev/nst0 /path/to/data
>
> Googling tells me tar’s max file size is 8Gb and my files to be backed
> up (which are highly compressed anyway) are all around 8Gb – hence even
> only 2 of them will create a tar file over 8Gb.   I’m happy to remove
> the z so remove compression but is the way to this really (seems awfully
> clunky)_ to write a script to supply each file to be archived as the
> second argument to the command above.   So my tapes will end up with
> 500 .tar files if I have 500 files to compress?   Doing it as one .tar
> file – or even one .tar per directory is going to result in .tar files
> of over 200Gb so possibly the reason for the errors.


tar has been able to cope with files over 8G since the early 2000s -
there was a limitation on the file-size field in the tar header previously.

Alternatively you could try pax [1]. Bonus rabbit hole [2] :-)

> If anyone’s wondering what error codes I’m getting, it’s usually “file
> too big” (I’m paraphrasing).
>
> Lastly – I’ve not found any decent GUI based (free) software to do
> this.   Grsync didn’t seem to like my tape drive – not sure why
>
> Cheers
>
> R
>
>


Cheers

Brad

[1] https://pubs.opengroup.org/onlinepubs/9699919799/utilities/pax.html
[2] https://mort.coffee/home/tar/
--
Brad Macpherson

--
Please post to: Hampshire@???
Manage subscription: https://mailman.lug.org.uk/mailman/listinfo/hampshire
LUG website: http://www.hantslug.org.uk
--------------------------------------------------------------