Problem slow boot with apfs on ssd external

Can anyone else confirm this? I don't have access to the external SSD anymore but I'm curious if the issue has been resolved.

Not fixed for me. But I don’t boot off my external apfs volume. So I wonder if the delay is the firmware trying to decide if the volume is bootable or not.

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.

If only mine was just 4 minutes. 90 minutes is about what I get with a MacPro (2013) and Mojave. It was the same with High Sierra. And i just replaced my samsung 860evo (in an inatec case) with a sandisk extreme because i was convinced it was the samsung going bad... waste of £200 there.

Thanks apple... no it was nothing. Really... nothing...

Needless to say the chances of me buying another mac ever again are pretty bloody slim... testing of any description seems to have been thrown out completely in the last few years with all apple products

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...

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.

@PCzzz, I'm glad you resolved it for you, but I don't see why ejecting the drive would make a difference. The drive basically gets ejected when you reboot or shut down the computer.

Based on what you said, I booted to the old, internal drive, installed the T5 software and it found a firmware update since the last time I had done this. I installed the firmware, ejected the drive just for the heck of it, and then rebooted. The problem seemed to be gone! The computer chimed, and I could see it accessing the T5 twice, then it quickly found the T5 as a startup volume and booted up. However, when I shut down and powered it up later, the startup delay was back.

I did file a bug report with Apple on this; we'll see what they say.

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 !

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.

Exactly the same problem on my external USB SSD. Very slow boot 1-2 min. since Mojave upgrade. On High Sierra with HFS+ the same drive started in ~20 sec. In Mojave from start to boot menu (holding Option key) takes ~30 sec. Then from boot menu to Mojave desktop 1-2 min.

My other problem is that my Recovery partitions disappeared after Mojave upgrade. My SSD is now formatted - first partition HFS+ (El Capitan), second partition is APFS with Mojave. No Recovery volumes appear in the boot menu. Booting to El Capitan (on the first HFS+ partition) is also slow (30 + 20) sec.

The Thunderbolt case allows TRIM command to pass to SSD, while USB case prevents the TRIM to reach the drive. There are a lot of users that complain about slow boot with APFS on High Sierra as well. Some claim that boot time is slow after enabling TRIM, others that after disabling TRIM. Another user restored his boot volume from Time Machine and his boot time reverted to normal.

I will try complete format and restore from backup, but I suspect that APFS requires TRIM to work.

Mojave requires APFS, but APFS does not require TRIM to work. Boot time got fast as soon as I put the SSD into the Thunderbolt 2 enclosure. I activated TRIM after that. As I understand it, TRIM is write-only and boot time is only affected by read-times. My SSD was pretty fast without TRIM. And it was still pretty fast with USB3 after log-in. The problem is the dark screen before Apple logo. I could live with the 40 seconds after that, but I cannot live with the 4 minutes plus before the Apple logo appears. The enclosure was pretty expansive: 106€ for a metal case with a pretty small board in it. I was lucky enough to at least have a thunderbolt 2 cable already.

Tommorrow I will try something. I will hook up my external SSD in a USB3 enclosure at my wifes Mac Mini. The Mini has not been updated to Mojave an runs on High Sierra. I want to have a look a what happens during the time before the Apple logo shows. The interesting part is, that my Macbook Pro shows long boot times even when I boot from the internal SSD with the USB3 SSD connected. And all my other drives start working, too (ie. the backup drives, although they lack a boot partition). Isn't that strange?

I wonder if Disk Utility shows "Solid State Drive: yes" for your SSD (in thunderbolt case). In Disk Utility select the drive, then Cmd+I to show Information window. My drive shows "Solid State Drive: no", but it's in a USB 3.0 case.

Also, do you see any Recovery partitions when you hold the Option key at startup?

It seems that this problem is not new. I tested rEFInd boot manager on my Mojave USB SSD and it's very slow, too. But I found that a user (see Uncle Sam post) in 2013 that fixed the slow boot problem by placing rEFInd boot partition on his internal HDD:

https://sourceforge.net/p/refind/discussion/general/thread/bc570433/#625f

I also noticed that boot is very fast if I force shut down (holding 5 sec.) the power button. Not a fix though.

I have exactly the same problem. In High Sierra, there was the option to keep HFS+ but this option is gone with Mojave 😟

You're right, issue not specific to T5 same issue with a SSD Crucial CT500MX in USB enclosure

Any chance to get a fix from Apple ?