On my iMac with Mavericks I downloaded the Yosemite upgrade, or rather tried to. The progress bar stuck at 50% and after waiting an hour or so I powered down. Trying half an hour later the download continued successfully to the point of install. The progress bar stuck again around 50% so another hour wait before powering down. One more attempt with the same negative result. Any suggestions for best way forward or backward will be gratefully received. I will let the iMac and myself cool off overnight and consider a restart holding down the Alt key to use my back-up disk with Mavericks, unless I receive another solution. Roy
Roy, you do not state which “upgrade”, so let’s assume you mean the 10.10.5 update rather than the complete Yosemite 10.10.0 and later, to replace Mavericks.
It may be that downloading and running the OS X 10.10.5 COMBO updater would solve your problem by removing questionable oddities that may have accumulated during successive version updates. Combo updaters update from the baseline OS to the latest version (10.10.5).
Download here.
Some other thoughts: many users just pile in to upgrading their computers (Mac, Windows, Linux) without exercising what the MBA graduates refer to as “Due Diligence”. It is essential to make sure that your existing OS is healthy before embarking on an upgrade. It is wise to make sure you have a very good and healthy backups (clone, Time m/c, backup discs, iCloud).
To ensure the health of your drive you might run not just Disk Utility’s Drive and Permissions checks, but you could also restart with the shift key held down (Safe Boot) and then restart normally. Purists might want to run Onyx (free, from Titanium.fr — but ensure you download the appropriate one for your version of OS X and that you read the yellow triangle warnings relating to some actions and take care), and check everything out with that. Caches are tricky and can contain little corruptions that aren’t caught by the OS and build into larger issues. Cleaning them can be very helpful, at the cost of a subsequent (single) slow restart as the caches are re-established.
It sounds as though your installer has come up against a corruption and has given up the struggle. So you may, at worst, have to bite the bullet, erase the faulty drive or partition, do a clean install and add back your own files. Without sitting down in front of your Mac and getting a properly detailed history there isn’t much else to be added from a distance.
Having said all of that, El Capitan (OS X 10.11.0) arrives on 30th September, and should run perfectly happily replacing Yosemite. I have been running the latest public beta which purports to be the Gold Master here (although there do seem to be minor version number differences), with no trauma at all on a second Mac. Other members may have other ideas, and perhaps someone living locally can help you disentangle this.
Euan, many thanks for the reply. I am ashamed to say the upgrade I am attempting is from OS 10.9.5. to the latest complete Yosemite. Before I do anything today I thought I would own up to this in case it changes what you suggest. I did run Disc Utility's Drive and Permissions before starting the attempt to upgrade. I also checked that my bootable backup external drive and Time Machine were up-to-date. I am wondering if I should do a Safe Boot or try a restart holding down the Alt key? I could then move back to Mavericks and take a 'breather'.
This may be a silly question and wishful thinking but will it be possible to 'jump' from Mavericks to El Capitan, ignoring Yosemite?
Roy,
I expect you will be able to go straight to El Capitan from Mavericks.
I had problems with the Yosemite installation too (don't remember exactly now) and the whole thing is... well, let's say it's not Apple's finest hour. As Euan observed, El Capitan is due for release at the end of the month so I'd save yourself the trauma of Yosemite if I were you. After 2 days with iOS 9, I have to say it is looking much better than iOS 8, another not-finest hour, so there's room for optimism that Apple's normal service will be resumed.
Happy to help in October if you're still struggling.
Thank you Tony. Your comments have cheered me up! (a) That I am not alone in having a problem installing Yosemite and (b) that 'jumping' to El Capitan is a possibility. I will plan to do (b) and in the meantime have to get back to my iMac HD.
At the moment I am operating from the external bootable backup drive using Mavericks. I have had a chat with another helpful member who has pointed me to Disc Utility - Restore - Source: HD Backup - Destination: Macintosh HD. This it seems will erase the iMac HD and copy the HD Backup to it.
I plan to go through this procedure this evening when I have 2/3 hours to spare and have the the required 'medicinal' liquid to hand! Roy
Hi Roy, service interrupted by unforeseen circumstances. Here's my tuppence-worth to add to Tony's:
I (personally) would avoid the Disk Utility path. Instead start up your Mac from the Mavericks Emergency Recovery (invisible) partition. (Press cmd + R just before the startup chime and hold until the start is underway.) This should reinstall your current OS X System version from scratch, and should preserve all your data and network stuff without fuss. You might see a “world” icon if things are bad, in which case just follow the instructions.
(Option you are ALREADY adopting: use an external drive (either a clone or a freshly installed Mavericks setup) to run your Mac if you prefer to leap into El Capitan on the 30th or after, but I think it would be far better to recover the present situation asap and make sure everything works “as is” first.)
You could, of course, install Mavericks or Yosemite “fresh” on a newly erased drive or partition using your external drive, but that would be slow and maybe overkill - as Tony remarks El Capitan is so nearly here. I never had serious trouble with Yosemite glitches, but many people did, and it did take several updates to settle down - a bit.
The best (purist) way to install a new version of System software is always to install it on a freshly erased partition and then to import your data. This path has kept my Macs clear of dodgy issues for many years, and I suggest that this is what you should do when installing El Capitan.
Thank you for your additional comments Euan. I took up your cmd+R suggestion and after just a few minutes (without seeing a "world" icon) everything loaded but - some of the icons in the menu bar and in Safari looked slightly different than before. I then checked 'About This Mac' and was amazed and pleased to find that I was in Yosemite 10.10.5 !!!!!!
Many thanks to all who helped me on this subject. 'All's well that ends well'. Roy
Roy Rainford 