Subject: Re: gzip warning about > 4GB breaks amanda
To: J Chapman Flack <>
From: Greg Troxel <>
List: current-users
Date: 11/02/2005 13:51:46
J Chapman Flack <> writes:

> This thread, or one like it, went around a while ago, didn't it?  Wasn't the
> upshot that the format has a 32 bit field that contains size%4G, and can
> always be tested by comparing the recovered size%4G to the stored value?

Yes, and I think that's done.

> Strictly that makes it a probabilistic test - it could be fooled if some
> corruption changed the recovered size by an exact multiple of 4G (!) - I
> think that's a probability I'm willing to accept.

I'm not at all worried.

> In which case the message, if any, when the size wraps 4G should be
> considered an info message, not a warning, simply noting that the size
> exceeds 4G and will be stored and verified mod 4G, and not changing exit
> status. As an info message, it seems harmless to me and probably worth
> keeping.

I agree that there should at most be info and not warning/exit status.
It's not clear to me that there should even be an info message;
scripts don't expect gzip to output anything to stderr if all is ok
(and I maintain that compression output being > 4 GB is ok).

I think warnx vs warn is about not acting like perror.  This surprised
me when i read the code. 

        Greg Troxel <>