Post 10.3 Experiences

We’ve been using 10.3 for a while now, and overall it seems to be an improvement over 10.2. Once the pain of the transition has passed, the features of the new OS are starting to show through. The system appears fairly stable, and more responsive under moderate disk I/O load than 10.2. There also seems to be a an increased ability to administer the machine from the command line.

The most noticeable positive impact of upgrading to 10.3 has been the responsiveness with moderate to heavy disk IO. Under 10.2, the system was not at all responsive to remote logins, or command execution. The system gets fairly heavy IO usage with approximately 10GB of files available via http, and about 2GB of a cvs repository. All told, it tops 200,000 files. Cvs in particular was a burden on the system, because it touched so many files on every transaction. However, 10.3 seems to be handling the same load better than 10.2 did.

The system seems fairly stable, as far as uptime, but many userland tools seem to crash randomly. In the first 2 days up uptime, we’ve gotten 2 tcsh crashes, 11 cvs crashes, and a hand full of crashes in other tools. The tcsh crashes were both random during interactive sessions, and the cvs crashes may have been due to our configuration error. The other crashes appeared random. We definitely have fewer zombie processes on the system as well. Under 10.2, we would get zombie processes from cron and particularly crashreporter. We have yet to see a zombie process from either of these two, yet.

There also seem to be more command line tools designed to ease administration of the machine. 10.3 Server includes commands such ‘networksetup’, that allow the configuration of SystemConfiguration’s backing store with respect to networking options. This is a huge boon, since it was previously impractical to try to configure networking options from the command line. The biggest drawback of these tools, is that they talk to system daemons to accomplish their task. Trying to configure a chrooted environment is just as impossible as it was with 10.2, although slightly more dangerous. Now, you are presented with tools that work perfectly well, but you won’t be editing what you think you’re editing. Chrooted environments, a first line defense by sysadmins, have always had problems on OS X. Everything from user lookups being forced through a central daemon, to the cvs command crashing in Kerberos related functions, has caused chroots to be virtually useless on OS X. Kerberos seems to be particularly troublesome with chrooted environments, since it wants to talk to a system daemon. However, Kerberos applications seem to simply crash in chroots. 10.3 seems to come with more Kerberized applications, which means fewer things can run in chroots on 10.3, including sshd.

The trauma of the 10.3 upgrade is still fresh in our minds to say the gains were worth the trouble of upgrading, but the results have been largely favorable. Once things got setup and working, they seem to be working better than before.