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

The changes above seemed to help but I no more than finished adding the reply and bang, color wheel spinning and the the drive unmounted with the disconnect error.

So back to looking for an answer

Fixed. At least for me, and for now.

As I reported earlier, immediately after installing Mavericks, my external drives started randomly disappearing/apperaring. I gave feedback to Apple, and started scouring the forums.

I cannot relocate where I saw the suggestion of a fix:

Delete Google Drive.

So I deleted Google Drive, and have had no more drives vanishing and reappearing.

Hope it works for you -- and continues to work for me.

Hmm

I don't have a google drive connected but I do use gmail. Makes me wonder what could be acting like a oogle drive.

I have no "cloud" services connected.

I don't have Google drive installed.

I disabled Google Drive and within about 10 seconds of testing, my external USB drive disconnected by itself, re-mounted and then proceeded to do so again 3 times in about 5 minutes. This only happens on my MacBook Pro. The same drive on my iMac is fine-- both running Mavericks, OSX 10.9.

That is interesting. Maybe it has something to do with USB 3.0 and Mavericks? What are the specs of your macbook pro and your imac?

All right then.... it's something else.

However, I have not had any unmounts/remounts since removing Google Drive.

Scratch that... it does happen on my iMac too.... for some reason it wasn't happening at all and then I suffered a disconnection on my iMac about 2 hours into at 3 hour file copy. Since then, it's been disconnecting repeatedly.

Another hopefully interesting bit of info... I only suffered the disconnection on one external drive... a Fantom USB. A 1TB Western Digital 2.5" attached at the same time kept going without disconnect.

My MBP is a 2.66 GHz Intel Core 2 Duo, mid 2009

My iMac is a 3.4 GHz Intel Core i7, late 2012

Finally.. the disconnect only seems to occur when the drive is mounted. I unmounted via Disk Util and the drive has remained solidly connected so far. This makes me think it's not a physical connection issue.

I just tried re-mounting the partition and immediately received a 'Disk Not Ejected Properly' message and the drive completely disappeared from Disk Utility.

anyone tried this

http://support.apple.com/kb/HT3964

Buddy of mine said to try it but I need to give TM some time to finish first.

Resetting SMC didn't help

Now I have reset the SMC and the PRAM

will repost when it works or fails

That did not take long

SMC and PRAM reset di nothing to improve

Time Machine logged this

Property list invalid for format: 200 (property lists cannot contain NULL)

Starting manual backup

Backing up to /dev/disk1s3: /Volumes/TimeMachine750/Backups.backupdb

Forcing deep traversal on source: "MacBookProSSD" (device: /dev/disk0s2 mount: '/' fsUUID: F2FEAA99-446B-31A9-8014-EAFE7FDC1AAA eventDBUUID: 35305D88-884C-4FF4-90D1-D1ADA3E2CA8C)

Found 617749 files (Zero KB) needing backup

104.9 MB required (including padding), 712.12 GB available

Waiting for index to be ready (100)

Stopping backup.

Error: (-36) SrcErr:NO Copying /Users/twoodard/Library/Mail/V2/IMAP-terry.w.woodard@imap.gmail.com/[Gmail].mbox/All Mail.mbox/D4037B67-A3B7-4141-8FFB-1DB08B2F8C59/Data/1/Messages/1406.emlx to /Volumes/TimeMachine750/Backups.backupdb/Terry’s MacBook Pro/2013-11-12-174943.inProgress/3EEB838A-8F0B-4B29-9887-6DB2C9E07D7A/MacBookPr oSSD/Users/twoodard/Library/Mail/V2/IMAP-terry.w.woodard@imap.gmail.com/[Gmail].mbox/All Mail.mbox/D4037B67-A3B7-4141-8FFB-1DB08B2F8C59/Data/1/Messages

Copied 10864 items (2.64 GB) from volume MacBookProSSD. Linked 104.

Error writing to backup log. NSFileHandleOperationException:*** -[NSConcreteFileHandle writeData:]: Input/output error

Copy stage failed with error:11

Error writing to backup log. NSFileHandleOperationException:*** -[NSConcreteFileHandle writeData:]: Input/output error

Backup failed because the destination disk was ejected or disconnected unexpectedly!

Backup failed with error 27: The connection to the backup disk was interrupted.

This seems to only occur on my external HDD's that are partitioned (NTFS and Mac OS). When I use a

Mac OS Extended (Journaled) partion drive only, there is no issue. Perhaps you have the same scenario?

all mine are journaled

But now im in a unique place, i happened to just receive a new iMac and it is loaded with MtLion

All the drives work fine

But on my MacBook with Maverick, no go

Also have a powered hub coming, will also report on that when it arrives

I'm also having the same problem, I have a WD 2TB my book essentials connecting via USB 3 that keeps unmounting it's self. I just connected it to a windows machine and it works without a problem. However I also have another WD 1TB drive that's connected via FireWire 800 with no problems. Has anyone figured out what's going on here? I am not even able to gain access long enough on my Mac to reformat it.