Re: cvs repository files being corrupted

[Todd Denniston]

Jeremy Birch wrote:
> Dear CVS,
>
> We have a fairly large CVS repository with a few hundred binary files 
> and thousands of ascii ones. On a fairly regular basis (and increasingly 
> over the last month or so) we have noticed repository (*,v) files being 
> corrupted and thus failing to checkout.
>
> The symptom is that the ,v file has a large amount of NULLs (several 
> hundred) just after the @@ marker in the file, ie something that should 
> look a bit like
<SNIP>
> What it feels like is that locking is failing ie two server processes 
> are accessing the file at a critical time and the file is truncated (by 
> the other process) part of the way through the write by the main process 
> - this gives the packing with NULLs, and the tail of correct data.
>
> Is this a plausible explanation?
> Is this a known bug?
> How do we fix it?

Q1) is your repository on an nfs or smb share (or other network filsystem)?
Q2) what access method are you using, i.e., :ext:, :pserver:, :local:, or 
direct to drive?
Q3) which distribution version of Linux are you using?

This reminded me of some problems seen back in 2001:
http://lists.gnu.org/archive/html/info-cvs/2001-01/msg00003.html
http://lists.gnu.org/archive/html/info-cvs/2001-01/msg00016.html

http://lists.gnu.org/archive/html/info-cvs/2001-05/msg00202.html

I think validate_repo.pl is something you may want to use as well, it searches 
for faults with the ,v files IIRC.
http://cvs.savannah.nongnu.org/viewcvs/ccvs/contrib/validate_repo.pl?rev=1.1&root=cvs&view=log

> We are currently using version 1.11.14 for our server, and will be 
> trying 1.11.21 instead to see if that fixes it, but we can see no entry 
> in the release notes covering this issue.
>
> Cheers
>
> Jeremy


--
Todd Denniston
Crane Division, Naval Surface Warfare Center (NSWC Crane)
Harnessing the Power of Technology for the Warfighter