--On Tuesday, September 27, 2005 17:46:03 -0700 Jerome Pioux <jerome.pioux AT
bull DOT com> wrote:
> Frank, thank you for your explanation.
>
> I didn't loose any data, what the links pointed to were backed up in other
> DLE as you mentionned and were successfuly restored.
>
> However, if it was only a couple links like /usr/local pointing to /opt/local
> as you mentionned in your example, I could recreate them easily... But when
> you have applications or users that use links everywhere, well this is
> another story :-(
>
> I guess I was hoping that, somehow??? even without following the link itself,
> Amanda or Gnutar would be able to store where it was pointing to?...
>
> So, if I understand you correctly, there is NO WAY using Amanda/Gnu Tar to
> get those links to point back to what they were poiting at - if correct, what
> about dump, would this solve this problem?
I may not have read your original posting closely and been clear enough in my
explanation. Tar should record the
link itself, it just doesn't follow it. In my example of /usr/local being a
link to /opt/local and you backup /usr,
then when you restore you should have the link local -> /opt/local recreated,
but /opt/local won't exist unless it
is already there or is restored from somewhere else.
If your tar is just creating an empty file (and not a link), then you may
either have a problem with your version of
tar or possibly an OS that refuses to create a link to a non-existent target.
You could test for both of those
manually outside of Amanda to verify.
Frank
>
> Jerome
>
>
> ----- Original Message ----- From: "Frank Smith" <fsmith AT hoovers DOT com>
> To: "Jerome Pioux" <jerome.pioux AT bull DOT com>; <amanda-users AT amanda
> DOT org>
> Sent: Tuesday, September 27, 2005 4:30 PM
> Subject: Re: Symbolic links
>
>
>> --On Tuesday, September 27, 2005 16:07:32 -0700 Jerome Pioux
>> <jerome.pioux AT bull DOT com> wrote:
>>
>>> Hi,
>>>
>>> I am surely doing something wrong but I have problems restoring symbolic
>>> links.
>>> Files that were symbolic links at backup time became empty file (0 size)
>>> after the restore?
>>> Backups were made using TAR (GNU tar 1.15.1).
>>> Any idea please? Thank you.
>>
>> It sounds like the links are being restored (a link does have a size
>> of 0), but you are wondering why what the link points to is not there.
>> Tar (with the options Amanda calls it with) doesn't follow the link, it
>> just archives the link itself (and doesn't cross filesystem boundaries
>> either, nor does dump).
>> If you backup /usr, and /usr/local is a link to /opt/local then all
>> you will be backing up of /usr/local is the link itself. If you want
>> what the link points to backed up, you need to make sure that whatever
>> the link points to is either its own DLE or part of some other DLE.
>> In my example it means you would have to backup both /usr and /opt/local,
>> or perhaps just / if they are both on the same filesystem (and you don't
>> care if you are backing up more than you need to).
>> If you are wondering why tar isn't called with the option to follow
>> links, it is because it would cause data to be backed up multiple times
>> (once for the original and once for each link to it), and because it
>> would make recovery fail, both from the increased size possibly not
>> fitting on the disk and from the recovered filesystem not being the
>> same layout as the original (could you find all the copies of a file
>> if you needed to change it, and woul you want to have to?).
>>
>> Frank
>>
>>
>>>
>>> - Jerome
>>>
>>
>>
>>
>> --
>> Frank Smith fsmith AT hoovers DOT com
>> Sr. Systems Administrator Voice: 512-374-4673
>> Hoover's Online Fax: 512-374-4501
>>
--
Frank Smith fsmith AT hoovers
DOT com
Sr. Systems Administrator Voice: 512-374-4673
Hoover's Online Fax: 512-374-4501
|
