2.3 Replication and lost Hardlinks

[Michael King]

This is actually one of the reasons I stopped using replication, once I
finally got it working.  Hardlinks have saved my butt more than once, and
saved a buttload of storage space, as well.  Being a media company, we
sometimes have huge files CC'd to 4-5 people.

I think this would be an excellent idea, and would definitely reconsider
using replication at this site if this was implemented.

Thanks,

Michael

Design / Hosting / Print / E-Media
------------------------------------
Michael King, Systems Administrator
Web International, Inc.
523 Louisiana Street, Suite 500
Little Rock, AR 72201  USA

501.372.0393 voice
501.372.1599 fax

mking at webinternational.net
http://www.webinternational.net

> -----Original Message-----
> From: info-cyrus-bounces at lists.andrew.cmu.edu [mailto:info-cyrus-
> bounces at lists.andrew.cmu.edu] On Behalf Of Roland Pope
> Sent: Thursday, March 30, 2006 3:38 PM
> To: info-cyrus at lists.andrew.cmu.edu
> Subject: 2.3 Replication and lost Hardlinks
> 
> Hi All,
> 
> It would appear from my testing of the new 2.3 Replication code, that you
> lose any 'SingleInstanceStore' benefits on the replica as hardlinks on the
> master cannot be reproduced on the replica.
> In my situation, I often have large emails sent to multiple recipients on
> the same server and I am relying on hardlinks to keep my disk usage down.
> In addition, I also have a small pipe between my master and my replica and
> any large emails sent to hundreds of users gets copied over the link
> hundreds times rather that the single delivery done by LMTP.
> I was thinking that maybe one way to solve this might be to have Cyrus to
> keep it's own DB of hardlinked Messages and then it could send a
> replication
> message that effectively resolves to "If you don't have message user.xxxx
> 'nnnn', see if you can create it by hardlinking to one of the following
> messages 'user.foo nnnn,user.bar.Filed nnnn' (if the message hash is the
> same), otherwise I will send you a copy".
> Then when you subsequently replicate "user.bar.Filed nnnnn", you should be
> able to link the message in from the copy you replicated to 'user.xxxx'.
> It would obviously be a little more complicated to deal with some corner
> cases, but what are people's thoughts?
> Is it worth trying to build something like this?
> Do any others on the list make heavy use of hardlinking who would be
> adversely effected by the current replication methodology?
> 
> Cheers,
> Roland
> 
> ----
> Cyrus Home Page: http://asg.web.cmu.edu/cyrus
> Cyrus Wiki/FAQ: http://cyruswiki.andrew.cmu.edu
> List Archives/Info: http://asg.web.cmu.edu/cyrus/mailing-list.html