Subject: Re: OT: recommendation for vm tuning for anoncvs mirror?
To: None <tls@rek.tjls.com>
From: Jeff Rizzo <riz@tastylime.net>
List: netbsd-users
Date: 02/26/2005 17:07:02
Thor Lancelot Simon wrote:
>On Sat, Feb 26, 2005 at 04:04:09PM -0800, Jeff Rizzo wrote:
>
>
>>Is the purpose of this for LockDir? Not knowing a tremendous amount
>>about CVS's internals myself, I wonder if some of the read-only
>>repository patches available in later (than the 1.11.17 that comes
>>w/NetBSD) CVS might help with this? I wasn't originally planning on
>>having separate spindles, but clearly I need to rethink this... I
>>suppose I can simply not raid the disks, as all the data is mirrored
>>from other sources anyway - I'll live with a dead disk taking the system
>>offline.
>>
>>
>
>Read-only repositories don't use locks. I don't know what changes
>you're referring to that aren't in the CVS in the NetBSD tree: I can
>assure you that anoncvs.netbsd.org has not run with locks, ever.
>
>
I'm talking about the CVSREADONLYFS env variable that (for example)
OpenBSD's cvs seems to support, and that I think I saw mention of in the
cvs 1.12.X distribution, but does not appear to be in NetBSD's cvs
1.11.17. It's quite possible (even likely) that I'm just missing
something, but I can't get things to work unless I set LockDir to a
writeable directory in CVSROOT/config.
>CVS uses /tmp for generating old (or branch) revisions of files, for
>generating diffs, etc. It creates mirror directory structures of as
>much of the repository as it's been asked to check out, in /tmp, for
>every checkout (or diff, etc.). This means creating tens of thousands
>of directories and files per copy, which is the reason for all of the
>effort to optimize the system to run efficiently with huge numbers of
>small directories.
>
>
Right. Got it. Thanks for the explanation.
>I suggest that you mirror / (and /usr, and /var, etc. if those are
>separate filesystems) and then use one partition on each of the two
>mirror disks for /anon-root and /anon-root/tmp respectively. If you
>lose either disk, you can just drop a new disk in and trivially
>recreate either the anon-root you lost or let the boot process
>recreate an empty /anon-root/tmp for you. :-)
>
>Thor
>
>
Doh! The perfect solution! :) Now, assuming I can get the colo staff
to swap my drives around so it will come back up after I inadvertantly
wiped out my bootblocks... :)
Thanks again,
+j