Slow Boot Up on Mojave - External USB SSD

Loner T hope you are out there. I just upgraded my iMac to Mojave and now the system is booting extremely slow. I have my Mac OS on an external USB SSD drive and my data files on the internal 1 TB drive. The system was working perfect until recently. I did a backup and then wiped the drive completely and reinstalled Mojave and it is still having issues. Not sure where to start. The system does appear to function fine once booted up and logged in. I was planning on running Bootcamp the iMac but with all of the issues I decided to keep running Fusion.

Thanks!

iMac (27-inch, Late 2013), OS X El Capitan (10.11.3)

Posted on Oct 4, 2018 5:04 PM

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iz2lsc

Level 1

8 points

Posted on Oct 10, 2018 5:32 AM

The problem is APFS. I installed Mojave on my external USB SSD disk (SanDisk) and it was automatically converted to APFS. Boot time were > 2 min.

After that I converted back the SSD to HFS+ using the Paragon converter and boot time went back to normal, with Mojave. So I hope that Apple will find a fix for this APFS issue soon.

Andrea.

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35 replies

Oct 8, 2018 9:06 AM in response to Loner T

I have the same problem.

With OSX Sierra boot from USB take 30/40 seconds.

Same configuration, install OSX Mojave on same SSD and iMac start on 3 minutes.

SSD on connected un USB3 port like a OSX sierra, but OSX Mojave starts very very slow!

uufff... :-(

Oct 5, 2018 11:26 AM in response to Loner T

USB3 to the iMac. Haven't tried a SMC Reset. I can do that now..

Oct 5, 2018 11:27 AM in response to Loner T

Apologies. YES I did a SMC Reset.

Oct 5, 2018 12:28 PM in response to Loner T

Nope ;-(

Oct 5, 2018 2:22 PM in response to Loner T

How do I do that?

Loner T

Level 9

59,536 points

Oct 5, 2018 2:36 PM in response to Dick Richards

About This Mac -> System Report -> USB.

Oct 6, 2018 5:48 AM in response to Loner T

Loner T

Level 9

59,536 points

Oct 6, 2018 7:30 AM in response to Dick Richards

Is the external SSD self-powered or powered by the iMac?

Oct 6, 2018 12:49 PM in response to Loner T

Oct 6, 2018 3:01 PM in response to Loner T

So you are saying there is nothing I can do LT?

Oct 6, 2018 5:46 PM in response to Loner T

Unfortunately I do not. I think I have an extra thumb drive?

iz2lsc

Level 1

8 points

Oct 10, 2018 7:02 AM in response to Loner T

This is indeed a workaround. I expect that Apple will provide a fix asap.

Andrea

Loner T

Level 9

59,536 points

Oct 10, 2018 7:44 AM in response to iz2lsc

My expectations are low. 😉

Nov 7, 2018 9:34 AM in response to Loner T

I have this same problem right now.

And I think it's the APFS, because I had this same problem using HighSierra when I accepted convert my HFS+ SSD to APFS. And just solved it converting back from APFS to HFS+. But when installing Mojave we don't have any chance to choose APFS or HFS+, then the SSD is automatically converted to APFS and the problem come back again. And now all we have to do is WAIT Apple take care about us.

Loner T

Level 9

59,536 points

Oct 6, 2018 1:17 PM in response to Dick Richards

If it is connected to a USBc port, there are some known power timing issues. Normal USB2/USB3 ports should continue to work. Is there an indication on the external SSD of the power state?

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Slow Boot Up on Mojave - External USB SSD