Re: Bug#557785: AW: Bug#557785: vzctl: symlinked config file: symlink overwrittenwhen --save isspecified

[Ola Lundqvist <opal@debian.org>]

severity 557785 important
thanks

Hi Robert and Debian Release team

On Wed, Nov 25, 2009 at 10:17:28AM +0100, Robert Heinzmann wrote:
> Olá Ola :)

:-)
 
> Is this a data corruption issue ? I think not in the first place, but It can become one.
> 
> Consider the typical HA scenario (* is the active config and node):
> 
> [NODEA*]-- --- [NODEB]
>           |
>         [CFG*]
>    (shared storage 
>        / drbd)
> 
> Let's assume you are changing the IP of the machine, or some other config parameter like some disk device on NODEA with --save. What happens is: 
> 
> 
> Before Failover, after --save: 
> 
> [NODEA*]    --- [NODEB]
>   |        |
> [modCFG*] [CFG]
> 
> 
> Everythign runs fine. Now if you are NOT aware of the bug, if you failover, your old config is restored and you may access wrong devices, use a wrong IP (duplicate?) etc ... This probably happens weeks after the change (--save) and you will have trouble finding the issue.
> 
> After Failover: 
> 
> [NODEA]    --- [NODEB*]
>   |        |
> [modCFG] [CFG*]
> 
> So for me it seems important that this bug can be found by people looking for this. If it needs fixing - yes, but how ? 

I see. Yes this is a data corruption issue, however only in the long term
and only if not following default practice. However it is still important to fix.

> A) 
> 
> * Fix in stable 
> (This will probably not break any existing configurations, it will just keep links that were removed before)
> 
> Pro: would help fast
> Pro: no side effetcs
> Con: does it break anything ? 

Would be a good thing if stable release team accept this kind of update.
Added:
Con: maybe side effects with 3.0.22 ? Likely not. Just as below.

> B) 
> 
> * Mark this bug as beeing a known bug up and including 3.0.23 in lenny (so that other peaople find it)
> * Fix in 3.0.23 (patch) 
> * Backport 3.0.23 to lenny
> 
> Pro: can be done now
> Con: what is 3.0.23 - is it a stable release ? 

Yes it is a stable release.

> Con: maybe side effects with 3.0.23

Likely not.

Backporting 3.0.23 is not an option just as backporting 3.0.24 is not an option.
See below.

> 
> C) 
> 
> * Mark this bug as beeing a known bug up and including 3.0.23 in lenny (so that other peaople find it)
> * Wait for 3.0.24 in sid (in the meantime live with a wrapper script/job)
> * Backport 3.0.24 to lenny
> 
> Pro: 3.0.24 will be the next stable
> Con: When will 3.0.24 arrive ?  

We do not yet know when 3.0.24 will arrive. Upstream have not given a clear statement
about that. Not more than "we should probably release it soon".

Backporting 3.0.24 can be done but only in the backports.org archive and not in the
real stable release. This will never be accepted by the release managers.

> 
> I think B) is not the best option. For me A) would be nice, hoever I can also live with C) for the sake of stability.
> 

I'd vote for doing the first part of B now (fix in 3.0.23) and then
let the Debian release management decide on whether this is allowed
to be fixed in stable.

Best regards,

// Ola

> Regards,
> Robert
> 
> 
> 
> 

-- 
 --------------------- Ola Lundqvist ---------------------------
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