Slow boot time after update to Mojave - External SSD

You could fix that by combining the two drives to create a DIY fusion drive as I did. Then the OS decides what content goes on the HDD (internal) and the SSD (external) invisibly to you. It works like a dream now the Mojave update has fixed the bug that was causing this particular setup to 'go slow'. My five year old iMac feels like a brand new machine. It's a bit tricky to do - there are lots of online guides to doing it though. The main thing is you have to copy all your content, reformat the drives, then restore all your content. Is a bit anxiety-making in the process but I'm so glad I did it.

MacOS 10.14.3 Update.

From almost 2,5~3 minutes to:

- 27 seconds from pressing the power button to Apple logo and another 26 seconds to Login screen.

I repeated a few times and it's the same.

I can say that is better now.

Personally, I can live with this.

But there is room for improvements.

UPDATING Mojave 10.14.3:

(Imac 2017 - 3,4 GHz Intel Core i5 - 8 GB 2400 MHz DDR4 - Radeon Pro 560 4096 MB - Fusion Drive 1Tb)

Boot without any external ssd connected (ONLY FUSION DRIVE) = ~ 25sec

Boot with the FUSION DRIVE and connected sdd external (SAMSUNG T5 USB Type C - 1Tb) = ~ 47sec

Boot with SDD external (SAMSUNG T5 USB Type C - 1Tb) = ~ 47sec

There was an improvement with this update .. but there is still a lot to do in my opinion 😟

I have an external SSD on a iMac 21" 2017 and boot time takes forever. Looks like the solution is going back to High Sierra.

Hi guys,

10.14.3 update is here!!

Seems that it works!!

Seems 10.14.3 fixed it here!

;-)

And again same problem here with a Samsung 850 EVO in an external Icy Box USB 3.1 enclosure connected to my iMac 27" late 2015 model. Had it running under High Sierra on HFS+ without any problems and with a very decent boot time.

Now that Mojave reformatted it to APFS, it takes about 2 minutes between the iMac start up chime and the Apple logo. After that, the boot process continues normally. This is not acceptable at all.

Had the exact same issue a couple of months ago when I reformatted the SAME SSD in the SAME enclosure from HFS+ to APFS (for testing) while being on High Sierra. After I switched back to HFS+, the problems were gone immediately.

So it's definitely NOT the SSD, it's something about the combination of USB and APFS.

So if anybody comes across a solution here, I would LOVE being notified!!!

Best

I have the exactly same problem.

I am using the external SSD as a boot disk in a USB C enclosure with a USB3.1 cable.

After the upgrade the boot time is increased to ~5 min.

The same problem was there in High Sierra when I first installed the SSD as a boot device. I noticed that the problem was due to APFS back then. Because the internal HDD was HFS+ while the SSD was APFS, I have read in some thread that if the boot drive is APFS and the internal HDD is HFS+ then the system takes more time to boot. somehow they were not compatible together so I changed the SSD format to HFS+. (now both the external SSD as well as internal HDD was HFS+) and I noticed the problem solved and boot time was ~20 sec.

Fast FW 23 sep.

After upgrade to Mojave- SSD format changed automatically to APFS, while internal HDD was still HFS+ and boot time increased to ~5 min. I thought that this might be because of the same problem of HFS vs APFS incompatibility. so this time I changed the internal HDD format to APFS (I think that was my mistake), because I have read a lot of good stuff about APFS. but nothing helped, the boot time is very long.

If anyone comes with a solution please let me know.

Thanks

Same problem for me and nothing is working.

Only I found out when you use the option key while starting up and he is not recognise your external ssd than unplug your usb and plug it back in will help.

But it still slow with starting.

Thunderbolt solved another problem in Mojave's bootloader. The problem was that Mojave's Startup Disk Preference Pane can't boot the selected El Capitan drive (put in a USB enclosure). After the restart, instead of El Capitan the Bootcamp Windows started. But if I use eSata to Thunderbolt cable for the very same enclosure and drive, then Mojave (System Preferences > Startup Disk) successfully selects and boots El Capitan.

There is an interesting read on the SuperDuper's Blog, that I was not able to comprehend fully, but It talks about similar problems with APFS and Startup Disk Preferences:

https://www.shirt-pocket.com/blog/index.php/shadedgrey/comments/its_awfully_quie t_out_there/

Your enclosure is indeed a Thunderbolt one, but I'm not sure if your problem is exactly related to this thread. We discuss a boot delay (black screen) of about 2-3 min. up to the Apple logo. It has nothing to do with slow boot after the Apple logo or slow shutdown.

Would you please explain what these two statements mean:

1. "Always booting off internal set as startup drive".

Is your external 4TB 850 EVO (Mojave) set as a startup drive or you boot from your internal HDD?

2. "Same thing happens with TB3 enclosure connected as simple data drive or even without anything connected."

This clearly means that you boot from your internal HDD, which may cause the problem after all. Do you experience slow boot if you disconnect any external enclosures (USB and Thunderbolt)?

First off, the enclosure is a TB 3 with only a TB 3 to TB 3 cable. I boot only from the imac pro internal drive. The Samsung SSD's are just external data drives formatted to APFS. I will disconnect the TB3 enclosure as well as the UAD Apollo X TB3 audio interface and report back on boot speed.

Unplugged both enclosure and UAD audio TB3 interface and boot was faster. Plugged TB3 enclosure back in alone and boot was a little slower but not too much. Then tried plugging in UAD Apollo X TB3 audio device and got a hard shut down panic crash twice in a row (see first line of report sent) and then unplugged it and plugged the apollo back in while in OSX and worked fine. I will try loading drivers for UAD again and see what happens.

{"caused_by":"macos","macos_system_state":"running","bug_type":"210","os_version ":"Bridge OS 3.2 (16P52540a)","timestamp":"2018-11-21 17:51:54.52 +0000","incident_id":"A4E42B82-CE1A-49D2-9F4B-BC07E805BFC7"}

Mac OS Mojave doesn't support anymore HFS+ in a boot Drive.

So you can't update your OS if it detects that you're using a HFS+ formatted drive. You need to use your original drive to update the OS and clone again to the external SSD.

I am on same situation, Fusion Drive 1tb inside, boot on Fusion Drive is fast, boot on Samsung T5 takes 1-2 minutes until Apple logo. On High Sierra with Samsung T5 in HFS+ everything was smooth.

You're right.

I've found int my IMac that the VM partition on the external disk wasn't mounted. You can check it running the diskutil command on a terminal: diskutil ap list

I've found the solution in this url: https://apple.stackexchange.com/questions/318266/mac-os-x-is-not-creating-a-swap -file

But this problem has no relation with the slow boot. Once solved (the VM), the boot time before logo is the same.

Agreed 100%. Apple need to fix this. It would appear (On my mac-pro 2013 anyway) that this is somewhere in firmware. Because it is slow BEFORE any logs appear when booting MacOS in verbose mode, and also affects booting with windows (BootCamp via an external SSD USB attached)