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Level 1

35 points

USB disk disconnects randomly

Hello,

I'm experiencing an annoying problem with my external USB disk. At random times (these can be short or long periods), it starts making some noise (like when it's intensively reading or writing) and then it vanishes (like if I had unplugged it). Of course, the system complains with a message like "You have not ejected your disk properly...".
Sometimes it happen 3 minutes after I turn the disk on, sometimes it happen after some hours of use.
And, in the Console, I don't see anything useful (only mds stating "Media not present", but that's obviously after the problem).

An idea what I can do/check?
(P.S: I hope to be in the correct discussion board: the Leopard board had "internal errors" and I could not post there).

MacBook Pro, Mac OS X (10.5.6)

Posted on Apr 6, 2009 3:43 PM

53 replies

Anic297

Level 1

45 points

May 29, 2009 2:36 PM in response to eww

Well, I thought of that, but since the problem had not been experienced for some months and I had not damaged the disk, I assumed it may be something else (related to software).

eww

Level 9

53,028 points

May 29, 2009 5:50 PM in response to Anic297

None of the updates I've applied to my MBP has done anything to change the normal, completely satisfactory behavior of my four external hard drives — two USB, two FireWire. I think you should give some more thought to the reliability of your drive.

Anic297

Level 1

45 points

May 30, 2009 2:56 AM in response to eww

Well, it still might be the problem...
I'll be careful about it, thanks for the advice.

stevekn

Level 1

26 points

Jun 7, 2009 3:29 AM in response to eww

Since the recent firmware upgrade on my Mac Book Pro 17" ( early 2008) I have also been having random "device removal" errors when using the previously fine-with-these-devices USB ports on the left of the keyboard.

The devices are a Flash card reader, with CFIII card, a USB sat nav watch, and a usb-serial adaptor connected to a polar watch down load accessory.

All have previously worked fine for over a year on these ports ( was it 10.5.7 or the firmware update that b *d it up?

Anic297

Level 1

45 points

Jun 7, 2009 1:13 PM in response to JJulian

A new answer: since the last update, it appears I can no longer disconnects the disk (it's the opposite). When I try to eject the disk, the system complaints that it is in use (whatever application tries).
Using the terminal's lsof command, I don't see any file used on the disk (obvious when I plug the disk and unplug it immediately after).
But, well, I haven't seen the previous problem since that... weird...

HarryRex

Level 1

0 points

Jun 14, 2009 10:02 PM in response to cjlavesser

I'm using an Intel Mac Mini and main backup drive has started randomly and frequently disconnecting. It runs through firewire and it's got its own power. Looks to be a OS problem. Gonna try updating 10.5.7 again though the stand alone download and not through System Update. I've heard this sometimes resolves problems. If anyone figures it out before me please drop a line. twitter.com/chrisohare

Moritu

Level 1

0 points

Jun 15, 2009 7:53 PM in response to Anic264b

I have the same problem both with a White Mac Book last Generation as with a MacBook Pro previous generation. Randomly it disconnects a WD640GB external HDD that has its own powersource, tried different cables etc. Once I thought I had it nailed down - disabling "put HDD to sleep" in Energy Saver but the problems still persists.

I use latest Mac OS X 10.5.7 but also had the problem on 10.5.6.

This seems to be a wider spread issue, maybe there is somethign wrong with the implementation of USB hardware or driver on the Macs. I do not see this kind of behaviour on an external LaCie Firewire 800 disk.

Via the developer connection I also contacted Apple over some weird Kernel Messages (IOUSB subsystem errors during startup) but so far more interaction has to follow.

If anybody know anything - please let us know.

Anic264b Author

Level 1

35 points

Jun 16, 2009 1:10 AM in response to Moritu

It may not help much, but I often see kernel panics saying something with IOUSB (I have activated the hidden option to show the panic's message on screen), but this appears on another computer (PowerBook 12 '') under certain reproductible conditions. It was, however, more related to an external modem.

By the way, no one wants to respond with a "I have corrected the problem" reply? It's somewhat my hope, having started the thread for that.

HarryRex

Level 1

0 points

Jun 17, 2009 4:18 PM in response to HarryRex

Installing the combo update of 10.5.7 seemed to have resolved the issue. Then the next day it started again although a lot less frequently. It now happens once or twice a day. Maybe 10.5.8 or Snow Leopard will correct this issue.

Jun 29, 2009 7:01 AM in response to Anic264b

I have an OWC Mercury Elite Pro enclosure using two 500gb drives over a FW800 connection to my iMac (2008 model).

The whole issue of connectivity has become a joke - my iTunes library is on there amongst most of my other media and I simply cannot either reliably access or copy these files off the drive. I constantly get random 'disk ejection' errors, thus stopping the copy process right in it's tracks or media playback or whatever.

I know the drives are fine and I know the enclosure is fine. Something happened during a software update that has caused this as it's been fine before.

Really, really frustrated by this now as I don't want one of these random disconnects to ruin the data on there.

Aug 3, 2009 9:46 PM in response to cjlavesser

has there been any resolution to this? I am having this problem with my macbook pro. driving me nutz!

ah_heng

Level 1

0 points

Aug 5, 2009 6:47 AM in response to sseligson

I have the similar problems with all my USB drives/ pendrive. Plug in and it just got disconnected intermittently. However, no problem when I connect it using Firewire (for the same HDD).

Apple, please help.

miao

Level 1

0 points

Aug 7, 2009 7:20 PM in response to Anic264b

I am having the same issue with my mac book pro. Newly purchased and running 10.5.8!
I hope Apple fixes this quickly...am I supposed not to use any USB devices anymore?

Javieng

Level 1

0 points

Aug 8, 2009 9:55 PM in response to Anic264b

I ran into this with my Mac Mini. I bought a new Vantec enclosure with WD Caviar Black HDD and was getting the random disconnect issue. I swapped out the USB cable to a better quality one and haven't had a disconnect since. It's only been a day or so but will followup if it happens again.

Aug 9, 2009 4:02 AM in response to Javieng

i don't think one day is a good indicator.... Take a few days for the problem to surface.

USB disk disconnects randomly