Q: Anyone else having problems with external disks unmounting randomly/suddenly on Mavericks?

Just piling on. Same problem: random unmounts of external USB drive with imroperly ejected disk error after installing Marvericks. Never saw the behavoir before the 'upgrade'. Should have stuck with 10.8 as the external drive is one of the main repositories for my home server. Have to frequently cycle the power on the external for the mac mini to see it again. Not easy when you're halfway across the country!

The disconnect issue (only with FireWire here, USB/eSATA fine) is still going on after update to 9.1. I got one thing new for one of the drive that disconnects: it does not dsconnect anymore, but it becomes unaccessible and put my system in a infinite loop (needs to power off/on the unit to get system back). When it happens, the console shows many many entries like this:

kernel: disk12s2: device is not ready

the "put to sleep" option on or off does not make any difference beside being less frequent when it's off.

There is another issue with Maverick extensively documented in this thread:https://discussions.apple.com/thread/5492808(10-30s delay before the finder displays the directory of a window)

Two solutions around this bug are provided. Solution 1 is to have the scroll bars on "always" (Prefrences/General). Solution 2 is to modify the auto_master file. I did both and it fixed the slow display problem and....not a single random eject of my FireWire drives since then!

The solution 2 has to do with NFS networking, could it be that is causing the random eject as well?

If some people can try and report their experience with FireWire drives....

i am opn mavericks right now and i was talking about this on an other thread and i concluded that my power line might have a voltage fluctuation problem as my usb hub would eject drives only when i would toggle the fan or the lights in my room on/off. but now after noticing this thread i am beginning to wonder. i had a similar problem with my older belkin 4 port powered usb hub and i threw it away thinking it was not working. how dumb of me. that was with mountain lion.

infact when i connect my iphone on the new usb hub now on mavericks it continuously connects and disconnects the device! i unplug the usb cable from the computer and let it charge via the hub, works fine!!! weird!

i am on a brand new mb air 2013 and this problem was there even on my old macbook pro 2010 a little over a month ago.

i guess i'll wait before buying a new hub. until then will use the drives directly pluggin them in.

I was having a problem with random unmounting of my Seagate NTFS drive.  Updating the Seagate firmware didn't work, and neither did anything else, until I upgraded my Paragon NTFS driver.  Unfortunately it was a paid upgrade, but it seems to have done the trick and the drive isn't unmounting anymore. Maybe this will help other folks with Seagate drive problems.

i clean installed mavericks. i am gonna try and see what happens now. i remember installing a number of ntfs drivers in my previous installition.

Neerav

Just an update. I'm still having problems and for now I'm not plugging in my external unless I really need it. I've tried selecting "don't put hard drives to sleep" and it still unmounts randomly.

I bought a new 1TB western digital usb3 drive today and I'm going to test it out. I'll let you all know what i find.

Just an update. After about a month after checking off 'do not put disks to sleep' the external finally unmounted unexpectedly. If anything it postponed the ejection for a good amount of time.

I am just getting this error. I was running my Time Machine backup and the external disk I was using just ejected randomly from my Mac Mini. Happened 3 times in an evening and it is getting very irritating.

I've had the same problems in the past week after buying a 3 TB Lacie external drive.  I've had to reformat the drive three times for multiple problems.  First, I received an error saying that the drive couldn't be mounted.  Second, my password wouldn't work to open the drive.  Third, I received some encryption error after it copied my HD.  Furthermore, when I went to Time Machine settings, there was not an option to Encrypt the files.

Like I said, after a third attempt at erasing the disk with Mac OS Journaled, Encrypted - trimming down my password to something simple...it seems to be working.  I've never had a thunderbolt connected HD before, I don't know if that could be a contributor or not but Time Machine seems to be working now.  It caused me a lot of stress and I hope it holds up.

Happy New Year!

Darin

If anybody had problems mounting their ™ back drive, try 'drive genius'. Just try and repair the drive using it. It will most likely fail in the repair but will be able to forcefully mount ur drive. From that point onwards ur time machine  drive would work fine as before!

Disk Utitlity or Disk Rescue would not mount, repair, erase or even read my disks. Again, mine were all usb 2, seagate and western digital drives all 2, 3 and 4 TB. I have a new seagate, formatted under 10.9 and so far is working fine, 2 weeks now. Still waiting on the western digital drive to arrive.

Disk utility failed for me too all the time. Drive genius reported it had problems as well. But i kept trying with drive genius and it showed up magically.

Drive Genius is getting a lot of praise but it's pricey at $100.  I'd like to try other options (hopefully free) before dropping $100 when I already spent $325 on the Lacie HD. 

Frustration frustration frustration -

Happy New Year!

Jettison (in the App store for about 2 $) does help those who only have the problem with not properly ejecting the disk when the OS is going in sleep mode. Jettison ejects all disk when the computer goes to sleep mode and remounts them when the user continues working. My girlfriend had the problem and Jettison solved it.

I am having a similar issue with my new 27" iMac with Mavericks.  I took a 1TB Western Digital Caviar Green out of my Mac Pro, and put it in an external drive enclosure.  I am trying to use it as my Time Machine drive--but it ejects randomly and the backup stops.  I have tried various things suggested in posts:  remove Google Drive, change the Energy Saver settings, etc, but no luck.  This is the second external device I am trying with the same results.