Coda File System

Re: RVM Log and Metadata Sizes

From: <coda_at_bobich.net>
Date: Wed, 30 Jan 2008 21:19:16 +0000 (GMT)
> > Is there an official limit on RVM log and metadata file sizes? I set my
> > log size to 2GB in order to be able to handle files up to 2GB. Ideally, I
> > wanted to be able to handle a FS up to 0.5TB, so I wanted to make a
> > metadata file of about 16GB. The biggest I've managed to get to work is
> > 4GB, otherwise things fail with an error. Does this sound about right?
>
> ISTR that the protocol for communicating among Coda hosts was
> 32-bit-size-oriented, but recently may have been updated to 64-bit
> sizes at the cost of backward compatibility, so it might be on a
> branch.  Anyway, this would impose a hard limit of 4GB (2GB if signed)
> on file sizes.  Note that this is a wire protocol issue, so a global
> substitution of off64_t for int won't help, but rather just introduce
> bugs.

Sure, I understand that, but if that is a wire protocol issue, then 
presumably, if I use the same version of Coda (e.g. 6.9.3) on both the 
IA32 and the x86-64 machine, they will still communicate correctly. Or am 
I misunderstanding?

> > On a related note, are any of these limits (file/log/metadata)
> > architecture dependant? If so are there any issues with having an
> > x86-64 and an IA32 node in the same replicated cluster?
>
> I don't think they're CPU-dependent, rather they depend on (a) large
> file support in the OS, and (b) a change in the Coda wire protocol.

Right - so if both Coda versions are the same and the same kernel version 
is on both machines it should work?

Gordan
Received on 2008-01-30 16:20:47