Tuesday, October 21, 2008

Parallels Desktop crashed my Mac Pro

I'll qualify the title shortly, but first let me recap. I've given Parallels Desktop a pretty decent chance. Only recently I wrote that I thought it had improved dramatically in the latest build. I've recommended it to friends, and they've purchased and installed it.

Yesterday, I was running Windows XP on a Parallels virtual machine on my quad-core Mac Pro, which has 4GB of RAM. It was smooth enough. I may have had as many as 20 other applications open (I generally just never quit applications—with 8 cores and 4 GB, why would I?), and then I logged my wife in as a second user. Then I launched a different Windows XP virtual machine in another instance of Parallels. As if that wasn't enough, she then launched some monolithic Java application inside that—and that's when it happened. According to Activity Monitor, the CPUs were doing essentially nothing, yet the whole user interface locked up. I couldn't even get Finder's Force Quit dialog up to kill Parallels. Finally, the disks stopped, and the mouse froze, and it was all over bar the power-cycling.

So while the title is true, I did happen to be punishing the machine a little at the time. I imagine it was a memory issue in the end. But, locking up to the point of requiring a power-cycle is a really poor failure mode. I think I'm over Parallels Desktop. I'm going to check out VMWare Fusion.

Thursday, October 16, 2008

Time Machine: still failing

The highest-traffic page on Mac Me Up (with a hit count four times its closest rival) is “Time Machine: Backup failed with error: 11”, which I wrote just over nine months ago. In the interim, I bought a Time Capsule, and things have been going fairly smoothly. Until yesterday. A Time Machine backup failed on the Mac Pro, and I ran into my old friend Error 11.

The symptoms this time were different to those I reported in January. backupd seemed to be complaining about an inability to move a single file: a preference list in ~/Library/Preferences. (Being unable to copy a single file, of course the entire backup failed. How robust.) I don't have the log handy to cut and paste, but that's not a big deal since the log adds essentially no useful information whatsoever, and certainly nothing resembling a cause for the copy failure. Just our old friend, Error 11.

I deleted the file (it was for a trial version of an Aperture plug-in), and then Time Machine complained about another one in the same directory. I moved the directory onto Time Machine's ignore list, and the backup completed fine. I'm not buying the idea that this is a disk failure or pre-failure. There is no other evidence of disk trouble. There is no SATA-subsystem logging of read or write errors. System Profiler lists the S.M.A.R.T. status as "Verified". Before I deleted it, I opened and viewed the file.

Time Machine needs to be fixed.

Thursday, October 2, 2008

iPod touch Mail Inbox out of sync

I read my mail via IMAP: all my mail sits on my mail server, and I use a range of clients over a handful of different devices to read it.
  1. Mail on a Mac Pro
  2. Mail on a MacBook Pro
  3. Mail on an iPod touch
  4. Mutt via a terminal into my FreeBSD box
  5. SquirrelMail via a browser.

Today, I've been using the first three of those at various times throughout the morning. I've noticed that Apple Mail on a Mac takes its time between marking a message for deletion on the IMAP server (at which point it's still recoverable), and actually having the server flush the deleted message (after which it's gone). Actually, that's slightly unfair, as even Mutt will wait indefinitely between those two actions—a message marked deleted by Mutt will sit there forever until you tell Mutt to purge them. There are two differences between Mutt and Mail here, though. Firstly, there's a visual indication in Mutt that the message is only marked for deletion (that is, it's still sitting there, just with a ‘D’ next to it), and secondly, there's a way to purge them (quitting Mutt or changing mailboxes will result in a prompt to purge). There are neither of these in Mail. When I delete a message in Mail, I can no longer see it (without changing to the Deleted Messages mailbox). (And since I can no longer see it, there's also no option to purge it.) But I can fire up Mutt at this point, and the messages are still there, marked as deleted.

Today, I guess I just happened upon the right combination of reading mail with too many mail readers, and making changes on all of them. Mail on my iPod touch was showing more than 50 unread messages in my Inbox (and they were all there, marked unread, and readable). Mail on the two Macs was showing what I expected: 5 messages, all read. (The other 45 or more had been deleted or moved to other mailboxes via filtering rules.) No matter how many times I synced Mail on the iPod touch, the views of my Inbox wouldn't reconcile. I tried disabling and then enabling the account on the iPod, but this didn't help. Finally, I fired up Mutt, viewed my Inbox, quit Mutt and answered ‘y’ to the prompt about purging deleted messages. On its next sync, the iPod touch displayed the same view of the Inbox as the two Macs. This was easy enough for me, but I don't know what people who don't have easy access to Mutt are supposed to do in this situation.