norman.walsh.name: Comments on /2007/08/09/mercurial

Comment 1 on /2007/08/09/mercurial

2007-08-09T20:09:59Z

I have this in my crontab which provides backup of my Mercurial repository:

# weekly Friday ZFS snapshot of ON-bldscripts gate
1 7 * * 4       /sbin/zfs snapshot local/Public/ON10-bldscripts@`/usr/bin/date +%Y-%m-%d`

Comment 2 on /2007/08/09/mercurial

2007-08-09T20:52:35Z

Mmmmm. ZFS. Sweeeet :-)

The point wasn't just that I wanted to backup the repository, it was that the integrity of the repository which is my backup of the real data needs to be tested every time it's updated.

Comment 3 on /2007/08/09/mercurial

2007-08-10T19:32:40Z

Are you saying mercurial is not transactional? That's a little bit scary.

Comment 4 on /2007/08/09/mercurial

2007-08-10T19:52:54Z

It's transactional; it has atomic commits and all the goodness you expect. I'm saying if you sigkill -9 the server while it's in the middle of a push, things can go horribly awry in a way that isn't detected.

I think it should be detected, but...

Comment 5 on /2007/08/09/mercurial

2007-08-22T13:10:00Z

I thought it was a distributed system. Calling it "server" seems to be a stretch.

I'd say kill'ing -9 the pulled side should give an error in the pushing side, or the system can't be called transactional.

I still find really scary that a revision control system ends without a "proper" error when it breaks and after it is broken.

Comment 6 on /2007/08/09/mercurial

2007-09-06T21:34:27Z

Very helpful! I've just signed up for a VPS (Virtual Private Server eg a Xen DomU) with limited memory and this is something I worried about. Thanks :]

-Tyler

Comment 7 on /2007/08/09/mercurial

2008-09-30T12:41:52Z

Note that system(...) in Perl returns 1+ in case the command failed. Perhaps you wanted:

system('hg verify') and die "$!";