<html> <!--AD_DND--> <head> <title>Maintenance</title> </head> <body bgcolor=#ffffff text=#000000> <h2>Maintenance</h2> of the <a href="index.html">ArsDigita Community System</a> by <a href="http://photo.net/philg/">Philip Greenspun</a> <hr> The most important thing to ensure in an ACS installation is that Oracle exports are being made. In general, it is unwise to rely on full recovery of a damaged Oracle installation. In theory, it is possible to recover Oracle if (1) the thing was set up correctly to begin with, and (2) you have an Oracle dba wizard around to bring the system back to life. In practice, I don't feel comfortable unless I have a full export of my Oracle database made nightly (using the Oracle exp utility, as outlined in <a href="http://photo.net/wtr/thebook/">my book</a>). <p> So check on this! <p> Disaster recovery or just rebuilding your Oracle installation for any other reason (change of block size, moving everything to new disks) would then consist of the following steps: <ul> <li>put the ArsDigita Community System into read-only mode by editing /tcl/ad-read-only.tcl; all the pages in the system that accept user input are supposed to call ad_read_only_p before offering users a form. When ad_read_only_p is set to return 1, people will still be able to read whatever they want from an ACS installation but they won't be encouraged to contribute comments or bboard postings that would get lost when you "flip the switch" to the new Oracle installation <li>build a new Oracle installation <li>import the latest export file (.dmp) <li>switch AOLserver to talk to the new Oracle installation <li>edit /tcl/ad-read-only.tcl to put the system back into normal mode </ul> <hr> <a href="http://photo.net/philg/"><address>philg@mit.edu</address></a> </body> </html>