Re: Backing up large unchanging files

[Colin Percival <cperciva@tarsnap.com>]

On 7/18/25 04:32, Tim Bishop wrote:
> On Thu, Jul 17, 2025 at 11:43:41PM +0000, Colin Percival wrote:
> > On 7/17/25 13:37, Tim Bishop wrote:
> > > On Thu, Jul 17, 2025 at 07:20:45PM +0000, Colin Percival wrote:
> > > > I *think* I can address this with a patch to say "cache trailers on large
> > > > files even if we've decided on our own to switch into lowmem mode".  You've
> > > > been using Tarsnap for a long time; can I assume that you can test a patch
> > > > for me once I've written something?
> > >
> > > Absolutely!
> >
> > Can you try this patch?
> >
> > https://github.com/Tarsnap/tarsnap/commit/61dab1292c19510f98d7dc7266b0e9320457ee97
>
> Initial impression is that it hasn't worked, but I need to wait for the
> daily jobs to finish so I can do some more controlled tests.
>
> Looking at that patch though it's checking mtime? Is that the mod time
> of the file rather than the size?

Umm.  I have no idea how that happened.  Yes, it should be checking the size,
not the mtime.

--
Colin Percival
FreeBSD Release Engineering Lead & EC2 platform maintainer
Founder, Tarsnap | www.tarsnap.com | Online backups for the truly paranoid