Attempting to reinstall Catalina due to the commonly mentioned slowness issue and I’m now dealing with the stuck on install issue at 10%. There was another post similar to this back in 2019 and unfortunately there was no follow up after level 1 advice offered but do see that multiple other people faced the same issue. I guess I’ll have to move off all data and try to rebuild from scratch.
iMac 27″, macOS 10.15
Try running the Apple Diagnostics to see if any hardware issues are detected. A failing hard drive could very easily be the cause of all the symptoms you have described. Unfortunately the diagnostics may not detect some drive failures. I can provide instructions for creating & using a Linux boot disk to check the health of the hard drive. Let me know if you are interested if the diagnostics do not report any issues.
If you are reinstalling macOS over top of itself, did you first try running First Aid to verify the file system is Ok? In fact it is best to run First Aid on the hidden Container instead. Within Disk Utility you need to click "View" and select "Show All Devices" so that the hidden Container appears on the left pane of Disk Utility. Even if First Aid shows everything as "Ok" click "Show Details" and manually scroll back through the report looking for any unfixed errors. If any unfixed errors are listed, then you will need to perform a clean install and migrate your data & apps back.
Even if there are no errors listed in First Aid you still may need to perform a clean install of macOS by first erasing the whole physical drive. Many users end up reinstalling macOS to the wrong APFS volume and end up with a mess and using up double the storage space due to mistake.
Try running the Apple Diagnostics to see if any hardware issues are detected. A failing hard drive could very easily be the cause of all the symptoms you have described. Unfortunately the diagnostics may not detect some drive failures. I can provide instructions for creating & using a Linux boot disk to check the health of the hard drive. Let me know if you are interested if the diagnostics do not report any issues.
If you are reinstalling macOS over top of itself, did you first try running First Aid to verify the file system is Ok? In fact it is best to run First Aid on the hidden Container instead. Within Disk Utility you need to click "View" and select "Show All Devices" so that the hidden Container appears on the left pane of Disk Utility. Even if First Aid shows everything as "Ok" click "Show Details" and manually scroll back through the report looking for any unfixed errors. If any unfixed errors are listed, then you will need to perform a clean install and migrate your data & apps back.
Even if there are no errors listed in First Aid you still may need to perform a clean install of macOS by first erasing the whole physical drive. Many users end up reinstalling macOS to the wrong APFS volume and end up with a mess and using up double the storage space due to mistake.
Your hard drive is failing. You have over 819 Uncorrectable Errors and over 20K Pending Sectors waiting reallocation. You can try installing and booting macOS to an external USB3 SSD drive since it is difficult to replace the internal hard drive. However, some drive failures can interfere with system performance even when booted to other media. Unfortunately if you have Apple replace the internal drive Apple will just replace it with another slow hard drive. Maybe an Apple Authorized Service Provider will offer to install an SSD upgrade.
Thank you for your reply. I’ve run diagnostics using recovery disk utility first aid on all devices and volumes. I’ve also removed all external extension devices where I store my iTunes library and have checked them as well. My time capsule failed to run in the last month or so also, so not sure if that’s a coincidence or not. I’ll now have to go out and get another external drive to ensure everything is backed up before I rebuild it.
Since I’ve passed all first aid runs without issue, I am interested in a Linux bout disk to verify the disk health. Don’t want to waste my time rebuilding if the drive is gone. Thanks. I’ll await your next steps.
-dmbiker1
Download a Knoppix DVD .iso image file with "EN" in the name for "ENglish". I know that v8.6.1 works, but have yet to try v9.x. Use the downloaded Knoppix .iso file as a source for Etcher (Mac/Windows/Linux) to create a bootable Knoppix USB stick. Option Boot the USB stick and select the orange icon labeled "EFI". While Knoppix is booting the Mac may appear to be frozen on the Apple boot picker menu so give Knoppix lots of time to finish booting.
When Knoppix reaches the desktop click the "Start" menu icon on the lower left corner of the Taskbar and navigate the menus to "System Tools --> GSmartControl". Within the GSmartControl app double-click on the iMac's drive icon to access the drive's health report. Post the entire health report here. If you have a Fusion Drive, then post the health report for both the SSD and hard drive. You can also run the drive's internal self diagnostics using the GSmartControl app as well.
Thank you for the assistance here and I've already started to look for ways to recover files that weren't backed up with timecapsule. I reviewed the report as well and I pretty much was expecting you to come back with some bad news. I'm wondering if I can use Knoppix to boot and try to recover some data before it is all lost? At this point this box will likely become a paper weight if it costs to much to replace the drive. Appreciate the advice though.
It is highly unlikely you will be able to recover any data from the failing hard drive since there are 20K bad sectors that are pending reallocation. Most normal utilities (even data recovery utilities) are not designed to work with a failing drive which produces errors. At best you may be able to use the "GNU ddrescue" command line utility available with Knoppix to perform a bit for bit clone of the hard drive to another drive of equal or larger size, but with that many Pending Sectors it could take an extremely long time (a week or more possibly). I have no idea how much of the drive can be recovered or if any of that data will be easily accessible after the process is done. Even after this bit for bit clone it may be necessary to run Disk Utility on the clone to attempt repairs to the file system or perhaps even a data recovery utility will need to be used on the clone. "GNU ddrescue" is the only utility I know of that is capable of transferring data from a failing hard drive to a good drive as it can skip past any errors to concentrate on copying the good sections of the hard drive and later go back to try to recover data from the bad sections. If "GNU ddrescue's" logging/mapping option is used the clone can be resumed if interrupted and multiple attempts can be made to recover data from the bad sections. It is very easy to make a mistake using "GNU ddrescue" when specifying the source & destination drives and when resuming a clone. There is unlikely to be any confirmed end to the cloning process as I'm sure there will be sections that will be difficult to clone. It is always a judgement call when to abort the clone and attempt to access the clone (you cannot attempt access until you are sure you are done with the clone since macOS will make changes to the cloned drive which could make a mess of things if you try to resume the clone afterwards).
Of course after the clone you will need to transfer the files from the clone to another location as you will not want to use the cloned drive after retrieving the data. After retrieving the data you will want to erase the good drive containing the clone so it can be used for normal data storage or a backup drive.
You can try contacting a professional data recovery service such as Drive Savers or Ontrack. Both vendors provide free estimates and both are recommended by Apple. However, with that many pending blocks I'm doubtful if even these professional data recovery services will be able to recover your data.
You will only get one chance at recovering the data since any attempt usually ends up making the failure even worse so choose wisely.
Thanks for that. I was also thinking about pulling the drive and placing it into an enclosure to see if I could mount it to anther APFS mac and pull off any data myself. At this point it is likely a lost cause though but might be worth a try. Not sure I'd have any luck with Target disk mode to another mac running in APFS with as many bad sectors as there are. Thanks again for all your help. Greatly appreciated.
With 20K sectors pending reallocation it is highly unlikely you will be able to access the drive or recover any files using traditional methods or utilities. I know this from personal experience of recovering data from maybe a hundred failing hard drives over the years. The two options I presented are your best options for recovering data from the failing hard drive. The more you use the drive the more macOS and any utility being used to access the data will cause the drive to repeatedly try to read the data from these bad blocks which will just make things even worse. Even having the drive powered on may continue to cause the drive failure to become worse. macOS will just keep getting stuck on any errors produced by the failing drive. I don't use macOS for data recovery for this very reason even though it is possible to use GNU ddrescue on a Mac. 20K sectors pending reallocation is a lot! I'm not sure either of my options will even work.
Like I said you usually only get one chance at recovering data from a failing hard drive.
Good luck with whatever option you choose.
Please see the attached extended text and health report. Thanks for the instructions as well. I can confirm that v9.1 worked successfully.
Catalina stuck on install post. iMac late 2013
