OS and architecture migration for DCC

Vernon Schryver vjs@calcite.rhyolite.com
Tue Jun 10 02:05:49 UTC 2008

> From: Gary Mills 

> but the databases are mostly empty.  The migration is from Solaris 9
> to Solaris 10, from SPARC (big-endian) to x86 (little-endian), and
> from UFS to ZFS.  Talk about a torture test!  

If it hurts (and it will), then don't do that.

> I'm using the same version of DCC in both cases, but recompiled for
> the Solaris 10 x86 server.  On that server, I started with a DCC
> directory (/usr/local/dcc) that was a copy of the one from Solaris 9
> SPARC.  I then reinstalled DCC so that the executables would all be
> x86 ones.  The daemons logged some interesting errors, presumably due
> to the byte order, but eventually seemed to run normally.  This was
> for dccd:
> Jun  9 16:03:02 setup01 dccd[1198]: [ID 702911 mail.error] dcc_db has page size 16128 incompatible with 15654912 in dcc_db.hash

Don't do that.  Instead, copy the only the ASCII files.

> Jun  9 16:12:06 setup01 dccm[1256]: [ID 702911 mail.notice] 1.3.86 listening to inet:3331 with /usr/local/dcc
> When I first ran `cdcc info', I got these errors logged:

Instead copy only the ASCII files including map.txt, dcc_conf, and
flod, and only some of those.  For example, lines for your external
DCC flooding peers must not be in flod files on more than one system.

> With single dccd and grey servers, is there any other way to do this
> migration and still maintain the data in the databases? 

No, there is no way.  Don't bother to waste time copying the database
files among systems.  Instead, let flooding rebuild the greylist and
main DCC databases on the new system from scratch as if the new
system had suffered a disk crash.

While you have both old and new systems running, you will want both
changes to be echoed on all systems.  So you will want to get flooding
going among the old and new systems.  With flooding, just let the new
system act as if it suffered a disk error that trashed the databases.
Disk or RAM problems are not exactly rare on new boxes, and so that
might happen even if you don't plan to start from that state.

Vernon Schryver    vjs@rhyolite.com

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