Saturday night's upgrade of our Koha server from the 32-bit 'Lenny' version of the Debian Linux operating system to the new 64-bit 'Squeeze' version went perfectly. I started the 'mysqldump', a full back-up of our Koha database, at shortly after 6pm and we were finished with the upgrade by 8:30 pm, with the exception of the reindexing of the bibs and authorities to rebuild the Zebra databases which finally finished Sunday morning.
In preparation I had created several sets of 'tar' backups over the past week of folders that wouldn't be changing, as well as a separate full backup of the '/home/koha' folder, (just wanted to be on the safe side), and had already ftp'd - copied - all of these to my machine for storage so all I had to copy Saturday night was the final 'mysqldump'. I had also downloaded the new Debian 'Squeeze' software, as well as the new 'drivers' file for this version, and created a DVD so that the upgrade would be much faster than pulling all the essential files from the network.
After I had the upgraded server back online, Jared from ByWater Solutions logged in to do the install of the Koha software -- the same version as we were on before, load the mysqldump that I had restored to the server into MySQL 5.1- that was upgraded as well; to make sure that everything was configured properly for Perl, Apache, and mail services; and that the SIP and cronjobs were restarted properly. Jared is very knowledgeable and thorough. I was able to watch what he was doing to setup our Koha server. He was very patient and willing to offer instructions as he went along so I could learn our system and the software better, which I personally that was very helpful and generous.
Everything seems to be working as it should and it is QUICK!! We are now able to access all 4Gb RAM on the server and now have almost 8GB of swap memory in use, so without changing any hardware we just tripled our usable memory which translates to more horsepower for Koha. I am confident that when staff login on Monday and proceed through their normal activities of the day they will see an immediate improvement in performance.