El Capitan GM having trouble making backup using Airport Extreme + external

There's some evidence on these forums of a potential El Capitan bug relating to USB connected external storage media. It's subtle though - it only seems to affect applications that have to access an external drive via USB to read/write a media library for example - it doesn't affect the ability to use the drive from Finder. Anyway, there are a number of threads on Time Machine woes alone on here - search "Time Machine Backup" for further reading...

-Max.

I have had one or two USB issues, especially with wired keyboard but I never use USB drives.

I'm having an issue with getting OSX to index (keeps getting stuck). I posted about it on a separate thread. I decided to try to force it to reindex again and added my HD to the Privacy tab in Spotlight. I noticed as soon as I did this that the speed of the backup increased dramatically. It's got 30 min left and I may actually have my first complete backup on El Capitan. Now I just have to figure out how to get indexing to work. Max, could you please take a look at the other thread I posted?

My search for your posts shows that the only other place you posted was on a thread last night where you report that the fix above worked for you. If you are referring to another, more recent thread, I can't find it. Could you please post a link?

Thanks! It says a moderator needs to approve it. I think because I included a link to a screenshot. Here is the text from my post. BTW. TIme Machine did finish my backup finally, so disabling spotlight was the fix I guess.

I'm having issues with getting time machine to finish its first full backup since upgrading. I was thinking its related to spotlight indexing so I deleted the index to get it to do a full reindex. The issue is that it's taking forever. It's been at it for 12 hours now and doesn't seem to have made a dent. Anyone have any idea what I should do?

i checked console for mdworker messages. It's full of these:

9/17/15 11:14:28.359 AM mdworker[20222]: LaunchServices: received XPC_ERROR_CONNECTION_INTERRUPTED trying to map database

9/17/15 11:14:28.359 AM mdworker[20222]: LaunchServices: Database mapping failed with result -10822, retrying

9/17/15 12:03:40.568 PM mdworker[502]: Failed to retrieve system accounts: Error Domain=com.apple.accounts Code=10002 "(null)"

9/17/15 12:03:40.572 PM mdworker[502]: [com.apple.corespotlight.log.index] Error caught while talking to the index agent, index:<CSSearchableIndex:0x7fe6e2539ae0; name="MDSFileProcessor", bundleID=com.apple.mail>, error:Error Domain=NSCocoaErrorDomain Code=4099 "The connection to service named com.apple.spotlight.IndexAgent was invalidated." UserInfo={NSDebugDescription=The connection to service named com.apple.spotlight.IndexAgent was invalidated.}

9/17/15 12:03:40.573 PM mdworker[502]: [com.apple.corespotlight.log.index] Finished "index items"(48) with error:Error Domain=CSIndexErrorDomain Code=-1003 "(null)"

So what actually worked for you (I've deleted the above) was:

1. From the Apple () menu, choose System Preferences.
2. Click Spotlight.
3. Click the Privacy tab.
4. Drag entire volume (your hard drive) to the list.
5. If prompted for confirmation, click OK.
6. Remove the volume you just added by clicking it and then clicking the minus ("-") button.
7. Close Spotlight preferences.

That's adapted from this Apple Support page: https://support.apple.com/en-ie/HT201716

I would add to that (for Time Machine backup purposes) to wait until the mdworker process has finished doing the re-indexing by monitoring it from Activity Monitor. Not waiting for it to finish before starting the TM backup could cause it to run very very slowly and perhaps even crash.