Slow boot time after update to Mojave - External SSD

*** do I know. It looks like the firmware thoroughly inspects each and every Bit inside the RAM chips or whatever.

BTW, I have 16GB installed (the "you have to order it from the factory" super expensive upgrade, you know). This was my last Mac, I swear. Bought it in Spring because my 7 year old iMac died. Had to buy 3 adaptor cables to keep my Firewire audio gear and external monitor running. MacBooks have been dropped here in 2016, Windows only on my notebooks now. I love them, they even have touch screens! Fook you, Apple.

Exactly same problem here. After installation of Mojave it takes about 3 - 4 minutes until the apple logo is shown and the boot process begins. It even takes ages to get to recovery mode or bring up the boot menu by pressing ALT key on startup.

I use an external SSD crucial MX300 1TB in an icy box case and USB3. My Mac is a iMac late 2013.

I already tried all the regular stuff like resting SMC or PRAM reset. I went back to High Sierra by restoring my Time Machine backup. Now the boot time is back to about 10 seconds.

Did anyone with the external SSD formatted as HFS+ installed MacOs mojave? how is the boot time.

My thought is if the file system is HFS+ on both the internal and external drive, it may resolve the problem. I don't know the technicality but, in the high Sierra this problem was solved when both the internal HDD and external SSD was HFS+.

Thanks

thanks @polo91, holding `option` for selecting boot drive manually brings back regular boot time, good workaround until a fix arrives.

Im on mbp 2016 with internal flash and apfs since high sierra btw. so this is presumably not just related to apfs or storage media.

I got the same issue like you guys, Late 2012 27" Imac with 256gb SSD with startech usb 3.0 cable, never had this issue with High Sierra, the time for the apple logo to come takes 30 secs then after that the iMac boots, dunno what apple has done here but this is terrible & hope they come with a fix, tried SMC reset no difference, hope apple engineers are seeing this thread.

Thanks.

miketoreno wrote:

You can enable trim support for external SSD with thunderbolt-enclosures.

Terminal: sudo trimforce enable

...yes, you can try that, but opinions differ about the advantages/disadvantages when doing so. Some say enabling TRIM actually slowed down their boot process/overall performance, others say it actually helped.

Mine is an Icy Box USB 3.1 enclosure. Time from system chime until Apple logo approx. 2-3 mins.

That would be really interesting... if really someone could confirm that they actually HAVE a USB enclosure that doesn't cause these boot delays with Mojave (on APFS!), I would immediately buy & try the same type...

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.

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....

....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.

There is disagreement here! I’m not a big fan of blithely following developers’ supported solutions. But others are - no problem that’s their prerogative. In this case you CAN clone Mojave to an unsupported format and it works, for me it has been ok for a while. But I have cloud and HDD backups in case of any problem. I live in remote Portugeuse village with erratic power so don’t want 3-5 minute boot ups every time the iMac restarts (quite regular). If you don’t have that issue then maybe sleep mode is better for you. But I’ll take my chances! Whichever way you go good luck! And I do respect those sticking to supported solutions... if that’s best option.

I dont know where to look for unsafe shutdown count and udma. i cant find them in mac system report window.

but in sata field where lacie stays i checked and saw this:

TRIM Support: Yes

SMART status: Verified

To read SMART parameters of your SSD you need a third party app as DriveDx or SMARTReporter. They provide trial versions. Or you may use the free "smartctl" which is only a command line tool, but actually all other utilities use it.

Unfortunately macOS DiskUtility shows only a summary as "S.M.A.R.T. status: Verified" (when It's able to read SMART data).

Perhaps this got nothing to do with the problem discussed here, but I just found out by accident my iMac doesn't swap memory at all when starting from my external T5 (iMac late 2013, USB3, 32GB). Is it possible this is the reason, does the OS fail to set up VM at startup? Would you check whether your swap is working?

I just came across this as I was running a huge batch of photos and the whole system eventually crashed with no memory left and no swap used.

Sorry if this is not of any help, I was just wondering ...