Time Machine Backup locks up WiFi adapter

Question

I have a MBP that connects to a shared USB external HDD via my Airport Extreme.  This external volume is only used for Time Machine and never is disconnected from the router. Under Snow Leopard, if I happened to be doing an auto backup (hourly) and put my machine to sleep/suspend by closing the lid, the backup would abort.  Upon resuming, and having my uptime counter click through another hour it would attempt again.  I had no issues with my networking adapter or anything.
Under Lion though, shutting the lid and coming back later results in a hung network adapter.  The Time Machine icon in the tray continues to spin, even though the drive may not be attached (Under Snow Leopard, TM would "wake-up" the attached HDD, a proces of 15 seconds, and it would appear on my desktop before the backup would begin).  I'll lose any associated AP that I was connected to over WiFi, and even browsing through the list shows both bands of my Airport AP available, even though it won't associate.
The only way out of this loop I've discovered is to disable the WiFi adapter, and waiting perhaps 30 seconds.  Eventually TM gives up and it appears to "release" my Wireless adapter.  Only then can I power it back up, and have it auto-associate to my AP.  Sometimes, attempting to Turn Off WiFi gives me a spinning beach ball for approx. 10-30 seconds.  The adapter status is "unknown".  Other applications continue to function, but the adapter is useless during this time.
This has happened several times...I'm at a loss to explain it, but it seems unique to Lion.  Somehow, some function doesn't allow TM to abort before my machine properly suspends. 
I also have a theory regarding the network adapter: I broadcast a different AP name for the 5gig band, which my MBP joins.  In Snow Leopard, my Mac would transparently join the 2.4gig AP name, mount the drive, and start backing up.  That doesn't happen in Lion; it seems to stay continually attached to the 5gig band SSID.
What other info would be relevant to the masses? Let me know and I'll try and dig it up.  Is anyone else having this same issue?

Answer 1

GeekApproach wrote:
Regardless of whether or not it's supported by Apple, it is a touted feature of the Airport Extreme.
Some Apple Store employees have told customers it will work, but it's not "touted" otherwise.  It's not mentioned, either way, on the online AppleStore page (several of us have been trying to get that changed for years).
And yes, as noted in the link, it does work for some folks for some period of time.  But most will, sooner or later, find their backups corruped, often beyond repair. Thus the recommendation to keep secondary backups.
Also, considering even the Time Capsule HDD uses an internal USB interface to make itself available to the networking hardware, I'm having trouble seeing why using an external device would be different given all other things being equal:
That's the rub; they're not equal.  The hardware inside the Airport Extreme is not the same as in the Time Capsule.  Apple won't say, of course, but those who've taken them apart think the buffer in the Airport is too small, and/or the chips aren't capable of as much verification and recovery as the TC's innards.  Thus the corruption problems, especially when there are WIFI or power issues.
We heard the same thing when Snow Leopard came out; those who thought they'd been doing fine for a while under Leopard and then had trouble some days after upgrading to Snow Leopard were convinced it was something changed in SL.  Ditto just about every "point" upgrade in both Leopard and Snow Leopard, and we'll no doubt see it when 10.7.1, etc., are relased.
Perhaps the next upgrade of the Airport Extreme will use the same hardware as the TC, or at least be improved.