A word about OS X Lion upgrades: backup!

98 times out of a hundred the OS X Lion upgrade will go swimmingly. But if it doesn't good backups are the only thing standing between you and a world of hurt - as I found out the hard way.

It's taken over 12 hours to achieve an OS X Lion upgrade due to various problems that most folks - with a single disk system - would never see. But I have a Pogoplug with a USB drive, an Iomega 4 drive NAS, a FireWire system disk clone, a FireWire Time Machine disk, a sweet DHK RAID 1 eSATA/USB dual drive array, a USB3.0 FireWire & eSATA drive dock and a 4 drive Promise Thunderbolt array.

In the dark my office looks like a small village of green, blue and yellow blinky lights. And to Lion it looks like a mess.

Woe is me I downloaded OS X Lion from the App store like everyone else - but then I did something different. I copied the downloaded file - Install Mac OS X Lion - to several different disks just in case I needed to reinstall it. And I also burned a bootable dvd.

Lots of copies protects your data.

I started the install and then went out to dinner. When I got back Lion was installed and sitting at the login screen. Just 2 problems: my account wasn't on the screen; and the password for the account that was didn't work.

I was locked out out my own machine.

After booting from my Snow Leopard system disk clone, I installed Lion again, using one of the extra copies of the installer I'd made, on a different partition, and ended up about the same place.

I then wiped the partition, did a clean Lion install and did a careful account setup. Rebooting into Lion and checking for software updates I then brought up Migration Assistant to move my accounts, documents and apps from the system clone to my new partition.

After that completed I rebooted and voila I still didn't have my old account to log into. Then logged into the temp account I'd set up and discovered that the old Accounts preference pane had morphed into Users & Groups. My old account was now in groups and I could not log into it or give it admin privileges.

The System Preferences help page was not helpful. Playing with the options - not recommended unless you have good backups! - I found that by right-clicking on my old account I got a couple of choices including "Add User or Group".

I chose to add a new user to my new account and used the name of my old account and the old user folder name. Lion then asked me if I wanted to use the old folder for this "new" account. I said yes and after a couple of minutes beach ball time, the new account was set up.

I rebooted, logged into my new old account and - finally - had access to all my data. Whew!

Recommendations

• Backup! I ran a Time Machine and and a system disk clone before I began the upgrade. The Time Machine backup had a problem that I later fixed, so it was a great comfort to have the clone as well.
• Multiple "Install Mac OS X Lion" copies. The DVD copy does the job, but installs are way faster from disk. And since each install destroys the install program, multiple copies means you can quickly reinstall without waiting for a download. I used 3 of the 4 copies I made.
• Don't go out to dinner. The install can jump the rails if you aren't babysitting it.
• Expect the unexpected. This is a major release and thousands of things have been tweaked. I knew how to solve the accounts problem under 10.6, but 10.7 does it differently in an undocumented way. Having multiple copies of my data - and a backup MacBook Air - let me consider each problem without the threat of total data loss scrambling my brains.