I'm trying to resucitate a discarded 2013 11″ MacBook Air with no internal drive and hence no OS.

The Apple Store Genius bar tested it and found the only problems to be the missing drive and broken display backlight.

Since I don't know if it's worth spending money on I'm doing an OS install to test it. We got Safari working with Wi-Fi from the installer so we know it does run.

But I only had USB 2.0 pen drives. We have the OS installer on an 8 gig one and we are installing to a 16 gig one.

The progress bar moved very slowly and the estimated "time remaining" was hilariously wrong. The progress bar eventually reached 100% and the time estimation went away but the USB activity light is still flickering with activity.

I know USB 2.0 is very slow, especially for writing and especially for a large amount of data. The install has been going for about 43½ hours so far with no error messages but also no other clues as to whether it's still going OK apart from the USB activity light.

I know this is an unusual situation and there are faster ways to do it but require spending money before knowing how well the machine will work.

Does anybody know or can find information from somebody who's done this before about how long it ought to take?

  • 1
    Don't forget, some USB2.0 pen drives support well under saturation speeds, especially for writes. It is not unlikely that your pen drive could be experiencing max writes of as low as 3-9MB/s. Good luck! Apr 26 '16 at 5:08

I've never done this before, but from the looks of it, the speeds will be limited by how fast your thumbdrives go.

If I remember correctly, an El Capitan install is around 8-10 GB in size, so the 16 GB one you're installing to should be sufficient.

USB 2.0 in reality can IO data at around 30-40 MB/s (although this depends on the make and model of your pendrive).

Using these factors we can calculate that an installation can take up to 6 hours for copying alone, not factoring the CPU overhead in installation.

Although 72 hours is a bit of a stretch, as long as your USBs remain flashing I would be fairly certain the system is doing something and not worry about it halting.

  • Yes I don't want to stop unless I'm sure it's hung in case it's just about to finish. Thanks! Apr 26 '16 at 4:22
  • Sorry I misestimated the time. It was more like 36 hours when I posted. It turns out that after the battery died and some time before I could borrow a power supply from somebody it so far seems that the install was complete after all. Apr 26 '16 at 12:56

I have just done this with El Capitan and an 8GB ancient thumb drive and it took precisely One hour and 15 minutes...

  • Wow. Did you install from or to thumb drive? Or were you using two partitions on the same drive? My machine has been working great for three years now, so worth the initial pain. Apr 7 '20 at 0:46

I was creating a bootable disk for High Sierra and I do agree the copy time was bit longer than expected. However it got over in 30-45 minutes..The entire process took around 1 hours and few minutes or so.

My guide: https://support.apple.com/en-in/HT201372

I followed the exact same steps and it worked fo me.

  • Can you please the instructions in the link that you provided? Links may change in the future or the page may be removed.
    – oa-
    Oct 23 '17 at 7:50
  • Were you using only two USB thumbdrives or just one plus an SSD or hard drive? Oct 24 '17 at 3:28

In my experience, it takes about two days.

Here's why I don't have a more precise answer:

I actually don't yet possess a magsafe2 power supply and have been testing and restoring this computer with borrowed ones when I can get one from a friend intermittently.

More than half way through the second day of install I had to return the power supply and the install kept running with the destination USB stick's LED still blinking for hours until the battery ran out of power.

When some time later I was able to borrow another power supply the machine did boot up into OS X El Capitan.

Since it was running out of a USB 2.0 pen drive it was exceptionally slow and any glitches may have been as a result of either an incomplete installation or OS-internal timeouts due to running far slower that it was ever intended to run.

  • ROTFL! You are hilarious. Yeah, it seems like it gets stuck at the last few bytes.
    – ATL_DEV
    Feb 24 '18 at 21:06
  • @ATL_DEV: After that success I invested in a second hand power supply and a USB 3 external hard drive. Later on a trip to China I got the screen's backlight fixed. I've been using it every day for over a year (-: Feb 24 '18 at 22:28

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .