Will Leopard Provide Real Rollback?

One of the problems of installing updates to your system is that any bad effects are sometimes not immediately apparent. Consequently, even if you can rollback, you might have moved on too far for it to be worth the effort.

At the moment, it’s good practice to back up your system before applying an OS update. Most of us probably don’t because there hasn’t been a seriously dud update since the early years of OS X.

However, from time to time some updates do cause smaller problems that initially go undetected. Windows XP has a System Restore feature. How good it is is unknown to me, but its intention is appealing. A search of the net didn’t turn up any similar rollback feature in OS X.

Two recent incidents highlighted the need for a rollback in OS X that could step back through system and application updates without affecting user data. Because of the way OS X is hung together, it is a difficult task with standard backup systems—even SuperDuper. It also means running and keeping a backup before every update, which kinda gets to be very annoying and disk consuming (unless you’ve got a Neiman Marcus diamond-encrusted 2TB hard drive from Seagate-Sothebys). The longer between the update and the discovery of the problem, the more difficult rollback via current methods becomes.

My problems began sometime after OS X 10.4.9 in March. Certain things on my Intel-based iMac have always been slower than my old Powerbook, but after 10.4.9, slowdowns have become my companion. No longer do I brag about happily running 20 or more apps at once. At the moment I have only five apps open. By comparison to how it used to be, how embarrassing! A search of the net did turn up one other person who felt his system was noticeably more bogged down since 10.4.9, so I’d expect there are more.

Since 10.4.9, I’ve been shutting down apps if I haven’t used them that day. Especially browsers. For instance, Safari, with only two windows and six tabs open, is sucking one 1GB of the virtual memory and 300MB of real memory (out of 1GB) at the moment! Also I’ve even taken to rebooting every few days. Again, how embarrassing!

My impression is the problem has something to do with memory management rather than CPU overload. The CPU graph is usually pretty happy and yet my system will be beachballing. A check of the memory panel in Activity Monitor showed most of the time my free real memory, out of 1GB, to be less than 50MB. Right now with Safari, Mail, DevonTHINK, Adium, and SuperDuper! open, free memory is only 100MB and virtual memory is nearly 11GB.

Now I know I run lots of crap on my system, but the abruptness of this decline in performance pointed to something more specific and, upon consideration, I realized the 10.4.9 upgrade corresponded with the performance hit.

Initially I did think it was Firefox as it had upgraded at a similar time. However, testing with other browsers showed the problem still existed. That said, either 10.4.9 has affected Firefox more adversely than other apps, or its update has, because it is definitely performing much worse than other apps.

Everything points to needing a memory upgrade; however I’d feel a bit ripped if an incremental upgrade is going to force that upon me.

The other recent incident where rollback would have been useful was last week when my printer’s driver stopped working sometime after I’d installed the latest OS X security update. In the printer dialog, it tells me that the printer’s panel is not compatible with my computer. That is, it is suggesting it’s not Universal. So now the printer’s extra dialog panels are only available when printing from Rosetta-based apps. Although I’d only had the printer a few days, I am reasonably sure I had printed fine from non-Rosetta apps before that. Plus a check of HP’s website says the driver is universal.

Now if OS X provided rollback of the system and applications, it would be an easy matter of testing and proving one way or the other both these issues I encountered.

OS X does provide “Archive and Install” which will take your system version right back to the version of OS X on your CD/DVD. But then you have to carefully apply the proposed updates of Software Update, lest you end up getting your problem update back. And it’s all time consuming. Generally speaking, rollbacks are meant to be simple and reasonably quick.

So, hopefully, Time Machine in Leopard will allow rollbacks that do not affect user data. Reading the info on Apple’s website doesn’t fill me with confidence though. Maybe someone who has played with it can vouch one way or the other.

What I want is a calendar driven rollback system that shows the update applied for each day and lets you individually roll them back. But for now? I’d just be happy if Apple’s updates had uninstallers.