Slow boot time after update to Mojave - External SSD

Thank you for the warning re HFS+ cloning not supported by Apple! Bombich also warn of that to be fair to them. But for now I will risk it. I back up everything regularly and all my files are in the cloud so if something does go wrong I have security.

The problem is that live in a remote part of Portugal with weak erratic power supply that often causes iMac to shut down, sometimes several times a day, although thankfully less frequent than that mostly. So, not through choice, I have to boot more often than I would like, 3-5 minutes would drive me mad. Bizarrely we just got fibre under PT government commitment that everyone will have access to cheap fibre by 2020, with speeds of 1000mbs if you want (I'm happy to settle for 100mbs + free phone calls + 150 TV channels for €29 a month with no upfront cost).

So great internet, rubbish power supply! Maybe they'll fix it one day - the village only got a power supply in the 1970s. But for me anyway, the unsupported HFS+ workaround is optimum for reasons explained.

I'm sad that Apple seems to be going the way of Microsoft in some ways - not fixing known issues for example, in some cases not even acknowledging them for months e.g continuing iPad Pro Smart Keyboard errors (eventually free replacement offered thankfully). Back in the day (I'm very old) Apple wasn't like this. But they do still make great products and overall are still way ahead of MS.

I look forward to a permanent Apple supported fix to the slow Mojave boot issue that seems to be widespread on SSMs. Until then I will live with the risks of unsupported workaround. Will report any problems.

Thanks again for the warning though, appreciated.

One more unhappy customer here. iMac 27” (late 2013) / Samsung 840 PRO External USB3 drive.

On High Sierra my boot time was less than a minute. Then I reformatted the external SSD and did clean Mojave install. Now it takes 117 seconds until the Apple logo is displayed. Total boot time is around 145 seconds now.

Good, proficiat. The Thunderbolt connection is extremely fast.

"So, in the conclusion, the problem is the USB3 enclosure (can be the TRIM functionality that is not present to the USB3 enclosure, even if it supported the TRIM and the UASP functionality."

You do not need Trim at all. On modern SSDs it is not read at all by the SSD controller.

Hi guys, I decided to try the suggestion from the other Alex because I have set up my Macbook the way I want it and I thought it would be nice if I could simply clone all my Apps, Settings, Files, etc to the SSD.

Bottom line: it worked. My total boot time is now 45 seconds (with APFS it is 2 and and 25secs).

Please note that I don’t keep any important data on my SSD, so I am not warried about it crashing. I also feel that the fact that Apple used HFS+ for so many years means that it will likely continue to work at least for a few more years.

But again, I did this at my own risk and I do realise that this is not officially supported.

Can you or anyone comment on stability so far in doing this? The Paragon APFS to HFS converter. Also the last update did not fix this issue and I'm beginning to think Apple is not going to do anything about this in future updates.

Hi, if you’re referring to cloning the HDD with Mojave to SDD with HFS+ format (actually my post although maybe Alex posted similar), I have been running that for few weeks now with no problems, boot time if anything is even quicker that just after clone. As you say any risk is mine but all is backed up on old WD external HDD and in the cloud so I should be safe!

I have decided to go another way now. I am now heavily using the Sleepmode instead of shutting down and restarting my iMac, so I only reboot quite rarely now. Using AppleScript, I have written myself two small shell scripts that reside on my desktop for quick access. One enables the "Allow drives to enter sleep mode" option within energy settings and then sends my iMac directlly into Sleepmode. After waking it up again later, I start the other script which simply disables the aforementioned option (because I don't like any of my drives going into sleep mode while the machine is on). Using these two scripts eliminates the tedious need of entering the password each time you change that option and saves some mouse clicking.

I have also permanently disabled the "Power Nap" option and the "Wake up on network activity" option in order for my iMac to do absolutely NOTHING while in Sleepmode. So I think my Sleepmode configuration is the closest you can get to fully shutting down - but at the same time, I now have zero boot time when waking the iMac up again. The iMac and the external SSD stay completely cold while in Sleepmode, no sound is heard. And I can use the keyboard to start my iMac instead of having to use the rear button ;-))

For me, this is the best way to go while waiting for Apple to fix this issue, but as someone else has already said, my hopes for an Apple fix start to vanish too... on the other hand, I don't want to switch back to HFS+ and I am not willing to spend about 150 Euros for the Thunderbolt solution either just to reduce boot times back to normal.

Hi all, I believe there is USB bug in Mojave which should be fixed with next update. I had exactly the same issue - boot time prolonged from 20 sec to 2 mins after Mojave installed on external SSD drive. But only USB3 connection is affected - if I connect the same drive via Thunderbolt (drive has dual interface USB3/Thunderbolt2), boot time is around 20 secs again with no other changes. And if I change cable again to USB, then I need to wait 2 minutes again.

I have reset the PRAM, reset the SMC, unplugged all peripherals apart from the SSD and nothing helps. Over 5 minutes of black screen before it boots....this is after creating a DIY fusion drive with an external USB 3 256gb SSD and the internal 3TB hard drive. 24gb ram and i7 processor so plenty of system resources....

Hi PF2UK. I’ve posted this workaround couple times but this is a very long thread so you may not have seen. I got this from Mike Bombich of Bombich Software who developed Carbon Copy Cloner. It reduced my Mojave boot time on Samsung T5 SSD from 3-5 mins toreboot frequently and this startup delay is a showstopper for you, I have one potential workaround – you could boot back to the HDD, erase† the T5 as HFS+, then clone the HDD --> SSD. Some people have reported that the HFS+ formatted T5 did not experience the startup delay. You can't install Mojave onto the T5 via the Mojave Installer without converting it to APFS, but you can clone your Mojave to an HFS+ formatted volume, and the format will not change.

† You have to [erase the whole device](When you erase an APFS-formatted startup disk, erase the whole APFS container) for "Mac OS Extended, Journaled" to be one of the formatting options.”

Sorry chunk missed from post just now for some reason. My boot time on T5 reduced from 3-5 mins to < 1 min. Workaround not supported by Apple but no probs so far : “if you reboot frequently and this startup delay is a showstopper for you, I have one potential workaround – you could boot back to the HDD, erase† the T5 as HFS+, then clone the HDD --> SSD. Some people have reported that the HFS+ formatted T5 did not experience the startup delay. You can't install Mojave onto the T5 via the Mojave Installer without converting it to APFS, but you can clone your Mojave to an HFS+ formatted volume, and the format will not change.

† You have to [erase the

whole device](When you erase an APFS-formatted startup disk, erase the whole APFS container) for "Mac OS Extended, Journaled" to be one of the formatting options.”

Thanks - I really appreciate the reply. But I don't think this will work. I have 2TB of data on my hard drive and the SSD is only 256GB. And they are set up as a single fusion drive, formatted with APFS. I don't think what you describe is do-able with my setup.

...well, you'd need another external drive with at least 2,5 GB storage space. Then you could clone your DIY fusion drive to that drive, boot from it, reformat the fusion drive to HFS+ and clone back to it. AFAIK, Carbon Copy Cloner supports fusion drives in all directions.

....yes, if you are doing a clean install. But not if you clone from an external drive to a HFS+ formatted drive. On the other hand (as I mentioned several times), running HFS+ under Mojave is completely unsupported by Apple as it's not meant to be done that way. That's the reason I wouldn't do that.

I'm also starting to think that there won't be any fix for this. Yet I don't think either that there's a special attitude behind not fixing it, I would say that it's simply too low a priority for Apple.