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iMac slow boot - prohibited sign
- Thread starter darkweather
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- el capitan imac 2012
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If the problem was about the ssd you could be right, but obviously it is about a code or something to chance with el capitan. and hence it's worth trying to do something. for example, the issue didn't occur last three times when i boot up mac.
I agree.
I have mentioned trying a different enclosure more than once.
The key word is "different", try a different brand. You may keep the SSD that you currently have. Although Kingston has been at the bottom of my "buy" list for a couple of years (below even OCZ
), you may accidentally have a reliable example. But, try it out in a different enclosure.
I try to understand those who claim that ssd or enclosure must be the source of the problem but i can't because:
1) https://www.reddit.com/r/applehelp/comments/4fbmb0/kernel_error_but_then_normal_boot_after/ this guy has same problem with different brand of ssd and without an enclosure
2) the problem doesn't occur everytime. if a phsycal machine is broken, it's broken every time. it doesn't sometimes work correctly and sometimes not.
3) os x 10.9 has no problem like this.
this all says that there is something wrong with os x and hence there is no guarantee that a new ssd or enclosure resolve the problem.
1) https://www.reddit.com/r/applehelp/comments/4fbmb0/kernel_error_but_then_normal_boot_after/ this guy has same problem with different brand of ssd and without an enclosure
2) the problem doesn't occur everytime. if a phsycal machine is broken, it's broken every time. it doesn't sometimes work correctly and sometimes not.
3) os x 10.9 has no problem like this.
this all says that there is something wrong with os x and hence there is no guarantee that a new ssd or enclosure resolve the problem.
I was about to post what Fishrrman wrote, at this point, I'd say live with it especially if your contention that its an OS X based issue is true. Nothing you can do will resolve this.
As an FYI, I'm running what I think is the exact same system you're running with an SSD connected as the boot drive via USB 3. I haven't seen that problem at all. OS is 10.11.6. The USB 3 enclosure is an Inland (dirt cheap...sells for less than $10 if I recall correctly) and the SSD is a Micron M500 series.
Apple seems to have some long standing problem with USB hosted drives. The most notable one being the ejection of them if they're asleep on some OS X versions, but if you search I think you'll find many other oddities as well. I remember someone, somewhere went into detail about the chipsets used in the USB devices being the culprit. It's probably something Apple should fix but probably hasn't.
There was a thread on the Apple Support Communities site where Apple Store "Geniuses" were actually telling people with the drive ejection problems to put a USB hub between the system and the drive and it apparently in some cases worked. I guess this is a "compatibility buffer." I'm not saying you need to do the same, I'm just saying there seem to be some USB compatibility issues.
Apple seems to have some long standing problem with USB hosted drives. The most notable one being the ejection of them if they're asleep on some OS X versions, but if you search I think you'll find many other oddities as well. I remember someone, somewhere went into detail about the chipsets used in the USB devices being the culprit. It's probably something Apple should fix but probably hasn't.
There was a thread on the Apple Support Communities site where Apple Store "Geniuses" were actually telling people with the drive ejection problems to put a USB hub between the system and the drive and it apparently in some cases worked. I guess this is a "compatibility buffer."
I'm not saying you need to do the same, I'm just saying there seem to be some USB compatibility issues.
I have a converted G-Drive with an SSD installed, and I too have not run into any issues. I just started setting that up and using that for some testing I'm doing. I still boot up to my Fusion drive by default but when I need to use a different version of OS X, I have that with the SSD. I mentioned converted, because originally it had a hard drive, but I grabbed an old SSD and swapped it out
@darkweather probably unrelated (the hardware and software are different), and I know that earlier in this topic I did not suspect a KEXT, but consider the following resolution to a slow boot issue:
https://forums.macrumors.com/posts/23111924
https://forums.macrumors.com/posts/23111924
i installed macos sierra. the prohibited sign is sometimes seen and sometimes not.
I don't think its an OS issue, maybe an odd combination of factors perhaps, but not a single attributable bug, At this point, I don't think there's anything else you can do.
Just to add some info to this long, old and detailed thread....
I recently purchased a used 2010 Mac Mini with the stock mechanical 320 HD. I was going to put a SSD in it, but had to wait until it arrived in the mail.
In the meantime, for experimentation, I wiped the HD with disk utility using the Snow Leopard startup DVD and partitioned the drive in half and installed Snow Leopard on one partition.
After that was fully installed & updated, I installed El Capitan on the second partition on the internal drive (that's why I got a 2010 Mac Mini).
During the course of playing with the Mac Mini with two new clean installed OSes and switching back & forth to compare..... Many times I get the "can't find startup disk" icon when booting up even though I previously chose the startup disk. And same as the op, if I hold the option key during startup and choose the disk (and wait a few seconds after choosing it) I can boot into the disk I want.
So in conclusion, (for other El Capitan users) the failure to find a startup disk is not related to USB, SSD, PRAM, SMC, or bad hard drive, but just the nature of the beast.
I recently purchased a used 2010 Mac Mini with the stock mechanical 320 HD. I was going to put a SSD in it, but had to wait until it arrived in the mail.
In the meantime, for experimentation, I wiped the HD with disk utility using the Snow Leopard startup DVD and partitioned the drive in half and installed Snow Leopard on one partition.
After that was fully installed & updated, I installed El Capitan on the second partition on the internal drive (that's why I got a 2010 Mac Mini).
During the course of playing with the Mac Mini with two new clean installed OSes and switching back & forth to compare..... Many times I get the "can't find startup disk" icon when booting up even though I previously chose the startup disk. And same as the op, if I hold the option key during startup and choose the disk (and wait a few seconds after choosing it) I can boot into the disk I want.
So in conclusion, (for other El Capitan users) the failure to find a startup disk is not related to USB, SSD, PRAM, SMC, or bad hard drive, but just the nature of the beast.