Re: [squid-users] Upgrade Squid but Use Old Cache

On Thu, 8 Jan 2004, Dodjie Nava wrote:

> a friend of mine is using redhat 8.0 & squid-2.4.STABLE7-4.rpm. he
> asked me to help him upgrade to squid-2.5.STABLE4. the only question is
> can squid2.5 use the squid2.4 cache? it's quite big already, around
> 100gig, and he doesn't want to start all over again. i'm not sure about
> this coz when i did upgrade our server, i did start my cache from
> scratch, but mine is only 10gig.
>
> our faq only has an entry for 1.1 to 2, but i'll include this in the update.

The cache in Squid-2.x and Squid-3 is upwards compatible between
releases.

This is except for the 2.4.STABLE1 and 2.4.STABLE2 releases where the
on-disk format got accidently broken and not even compatible with itself..
<url:http://www.squid-cache.org/Versions/v2/2.4/bugs/#squid-2.4.STABLE2-swap_meta>.
But even then it is upwards compatible unless one needs to make a slow
rebuild of swap.state.

It is not guaranteed that downgrading will always work flawlessly. In both
Squid-2.5 and Squid-3.0 new features is introduces extending the on-disk
format, and older releases may get upset when encountering objects using
these extensions. And it is extremely likely additional extensions will be
added during the lifecycle of Squid-3.

Regards
Henrik
Received on Fri Jan 09 2004 - 04:29:32 MST