Problem slow boot with apfs on ssd external

I had this problem also since 10 nov 2018 when I bought a Samsung T5 500GB SSD and installed Mojave on it. Sometimes 4 minutes black screen before the AppleLogo appeared! Totally unacceptable, although workable... But I think i solved it. The problem appears to be that installing and updating the Samsung T5 Firmware needs at least one explicit eject and re-attach of this (external) SSD. But that is not possible while it is the disk where upon the OS is working! And re-assigning another disk to be the startup-disk does not count as a formal eject of the T5-ssd, because the restart takes place immediately without ejecting the ssd (so it seems). The solution:

1. Make (or use) a different, bootable startup disk, change startup-disk to that particular disk en Startup
2. Then update (safety first) the firmware on the still attached T5 ssd and EJECT and re-attach the T5 ssd (several times, if you want to be sure)
3. Assign Startup disk back to the T5 and Startup. This will take long, the first time, but there-after the slow-boot problem is gone!

Everything is probably caused by the fact that I had NOT activated the T5 SoftWare and FirmWare + ejected and re-attached the T5 BEFORE putting a new macOS on it. I did that deliberately, because I thought Mojave would know best how to format and install itself on this tiny little gem. That is true, but every time Mojave tried to re-start while installing etc. it got lost in space, because the T5-firmware was not effectively installed... And while working on the T5, we all could not eject it ... because it was the disk with the active OS on it...

So: an unsolvable loop. Which will come back every time when you update the firmware ! Because this firmware is not really designed for a bootable external ssd. And that is probably caused by the necessity to make attaching the data as secure as possible (that is what the T5-password-software tries to achieve).

Thus: first formatting and installing/updating the firmware on the T5 and immediately ejecting and re-attaching it is necessary. Mac Mojave will then re-format the ssd to APFS while installing, but the firmware is then already safely working in this little thing.

Hello everyone,

i've found the solution.

A friend lent me a ssd thunderbolt drive, which I completely formatted.

With UtilityDisk have created a new APFS partition, and I used Carbon Copy Cloner to do a clone of the entire SSD USB3 to the new Thunderbolt SSD.

After the clone finished I've rebooted the mac, set the new drive as Startup Disk under the settings panel.

After the chime, now the apple logo appear after more or less 10 secs.

The boot time is now reduced from 2-3minutes to complessively about 20-30secs from the chime to OSX.

I've used only the Carbon Copy Cloner app, nothing else; nothing command settings, nothing particular settings.

So, in the conclusion, the problem is the USB3 enclosure.

Thank you for all, my friends !!

Suggestion from apple is that the conversion to apfs is not the correct way to move to apfs. You need to do an erase and format as apfs... obviously that requires moving your data.

initial testing here suggests this is correct but i am still moving data around to test once i have my data back on my drives...

The only fix I found is a thunderbolt enclosure for the SSD. Got mine today and boot time is normal, now.
The problem occurs before the Apple logo shows up. It took up to 4 minutes before the logo shows. After that boot time was about 30-40 seconds. With the thunderbolt enclosure it is between 10 to 30 seconds until Apple logo and another 10 to 20 seconds boot time. There have to be some changes with the USB boot loader, because it takes the same amount of time, if I press the ALT key while powering up --- up to 4 minutes with the USB SSD enclosure and a few seconds with the thunderbolt enclosure. Apple, it's time for a fix! I had to spend 106 Euros for a simple enclosure for my System SSD which worked just fine before Mojave!

No, no problems. Both formatted with APFS. All fine after I made the switch to the thunderbolt enclosure.
Since maverick1987 reports the same (he made that switch, too), I guess this is the only way to go for now.
But a pretty expansive one. For 106€ I could have bought another SSD......

In my case the problem disappears in the last Mojave update (10.14.3).

Regards.

Delock 2.5" Enclosure SATA HDD>Thunderbolt external enclosure

Installed an external ssd yesterday. Worked like a charm. Looks like the issue has been fixed in 10.14.3

That's too bad, I'm sorry to hear that.

I don't think this issue is specific to the T5, actually. A friend of mine duplicated it for me with his Sandisk drive in a USB enclosure with the same results. Prior to that, I had contacted Samsung and a Support person told me they are aware of the issue and that it happens with other manufacturer's drives as well.

You don't even need to have Mojave installed on the external drive, it just needs to be formatted as APFS.

Yes, I can confirm this: after much a-do during installing the Mojave 10.14.3-update, the start-up is now super-quick: 4 seconds black screen and 1 minute with the apple logo on screen. Very good, Apple!

Considering all the security (EFI) aspects that played probably a role, this is a neat solving of the unacceptable long start-up time. Especially unacceptable because it showed a completely black-screen all the time for 5 minutes ...! That is long, the first time, I can tell you.

But: I am afraid that the update problems will return with every new update, because every restart during the update, it could not find a startup-disk, displaying a blinking ?-Folder and not responding to ANYTHING except a long OFF press. And an Option+ON start to choose the startup-disk. And choosing "OS-Installer" (not the T5) from the list of startup disks. And the same Option+ON again until I could just only choose my external T5 disk.

But I know how to handle it, now. Just happy and a bit exhausted.

I took a brand new Samsung T5 SSD and formatted as APFS, then used Carbon Copy Cloner to migrate everything from the internal boot volume. Merely having it connected to my iMac results in a 1-2 minute delay in between the startup chime and it actually starting to boot.

So it would seem that at least with this issue there is no difference between having the installer convert your drive to APFS versus formatting it APFS.

You are right: after my first euphorie of a quick boot (and telling everybody about it), the slow boot came back just as you describe. I am sorry and sad. It is definitively a problem caused by the password-security FirmWare in the T5, which does its work even if there is no password activated (but the firmware always is ...?.). Actually: Apple has done some good work in realising a boot-up at-all. Well, it is still totally unacceptable that neither Apple nor Samsung gives us a solution or even a hint, how to install a T5 as a bootable ssd with reasonable boot-up-time (while the screen is completely black!). This way we cannot advice anybody to buy a Samsung T5 external disk when they want to boot from it !

Same here. Went from seconds up to 3 minutes until Apple logo shows and another 2.5 minutes until login-screen. Everything was fine and very fast with High Sierra. I use an external SSD in a USB3 enclosure. But I have a longer boot time with the internal SSD in my Macbook Pro Retina 2015, too. I already did a PRAM and SMC reset, checked the drives with Disk Utility and so on.

What can be done?

I recall to have my external USB3 SSD formatted with HFS+ and had the option to keep on HFS+ when installing HighSierra. This worked very well back then.

But still I can not understand, that the Trillion Dollar Company can not afford to test a new OS/filesystem booting of an external drive. I'm not sure, if they even want to fix this problem. Because after all, it's present since over one year when they introduced APFS with HighSierra. I am very disappointed.

Just a thought but perhaps if your internal drive is formatted to HFS it does not work well with the external APFS drive when booting up the external drive. I noticed a similar issue when I formatted an external drive to APFS and installed High Sierra on and tested a few weeks ago when my internal was HFS with Sierra.