iMac slow boot when USB drive connected

[Arcadeez]

My iMac is 2011 mid i7 3.4G with 16G RAM.
I realized that the boot up time is much longer after plug in my external USB drive.

If boot up with only ethernet cable connected, the time is 18 sec (until I see login prompt).
After connecting my USB drive, it is 48 sec!
What's wrong?
Any solution?

Thank you for any thought.

 

[simsaladimbamba]

It may scan the external HDD for a bootable Mac OS X version. I experienced the same, but since I sleep my Macs, I rarely even boot them now.

 

[Arcadeez]

If this is the case, the scanning is taking too long time.
Actually I have 2 USB drives connected.
I tested boot up one by one.
Connecting to old WD USB (with Firewire 400) My Book 1T : 20sec.
Connecting to new WD USB 3.0 3T My Book Essential: 45sec.

If both USB drives connected, which is 48sec!
If no any USB connected, which is just 18sec!!
What a big difference!

 

[NutsNGum]

Yeah, it happens. Some other post pointed this out earlier on in the week. I have something similar happen on mine. Same model. Not a big deal now as a previous poster said, I pretty much just sleep mine all the time.

 

[Arcadeez]

Is there any way to tweak or shorten the boot up time? Thx!

 

[likegadgets]

In addition to longer boot times, I also experience beach balls slowdowns as my 2011 27" 3.4ghz iMac occasionally scans 3 external drives (2 USB and 1 FW). One drive is time Machine, another is a nightly super duper image and the 3rd is for windows backups from the parallels VM.

 

[Arcadeez]

Yes. Beside boot up, I also experience the USB sleep and slow wake problem while I am using my iMac.

Not sure this is USB architect problem or my USB drive problem.

 

[Detrius]

It's a problem with the USB device. If you look in your logs (kernel.log or system.log), you'll see USBF errors pointing to an unresponsive device. Since it's a hard drive, it's also possible the drive itself is bad. You may instead see disk I/O errors in the logs.

 

[Arcadeez]

Hi Detrius,
Would you please teach me where and how to check those log files ? Thanks.
Arcadeez.

It's a problem with the USB device. If you look in your logs (kernel.log or system.log), you'll see USBF errors pointing to an unresponsive device. Since it's a hard drive, it's also possible the drive itself is bad. You may instead see disk I/O errors in the logs.

 

[Detrius]

Hi Detrius,
Would you please teach me where and how to check those log files ? Thanks.
Arcadeez.

You can use Console.app to look at the log files. The ones in question are in /var/log. If you're running 10.6, check out kernel.log. For anything older, look in system.log.

I don't have a copy of what the USBF errors look like off hand, but you should be able to search for just "USBF" and find them, if they're there. The ones I'm expecting you'll see say something along the lines of "found a transaction past the completion deadline on bus 0x06"... very roughly. Also, search for "I/O error" as that usually comes up when the system is trying to access a bad drive. from the disk ID, you can figure out in Disk Utility which disk it is. From the USB bus ID, you can figure out from System Profiler what controller the device is connected to.

 

[Arcadeez]

Thanks Detrius,
I found Console.app and checked it out.

There is neither I/O error nor USBF error.
I now try to upgrade my 3T WD USB drive's firmware to see if it can improve boot up time or wake up time.

 

[Arcadeez]

Just update the firmware for 3T WD USB drive.
There IS a bit improvement!


Connecting to only 3T WD USB 3.0 My Book Essential: speed up from 45sec to 43sec.

If both USB drives connected, which is improved from 48sec to 45sec!

BUT, it is still far slower than plain boot up which is just 20sec!

For anyone information, the firmware update won't affect data saved in the usb drive.
I took about 9 hours to backup all data (about 140G) in the USB drive before upgrading firmware...