Repeatedly failing to install MacOS from bootable USB installer to external flash drive

starbuckle wrote:

The disks are both USB sticks, yes. But they do both have promised speeds of "up to 400MB/s". Both are connected by USB type-C without an adapter.

FYI, the fastest SanDisk USB stick I could find is this one which has read speeds of up to 420MB/s, but write speeds are only up to 380MB/s.

https://www.westerndigital.com/products/usb-flash-drives/sandisk-extreme-pro-usb-3-2?sku=SDCZ880-128G-G46

Any of the other SanDisk USB sticks I could find which mentioned up to 400MB/s read speeds did not even mention the write speed which usually means they are embarrassed by the write speeds.....here is an example:

https://www.westerndigital.com/products/usb-flash-drives/sandisk-ultra-dual-drive-luxe-usb-3-1-type-c?sku=SDDDC4-128G-G46

And if you look closely, they usually mention sequential read or write speeds since that is when you will get the maximum speed possible.

You really need to look extremely carefully at the product documentation. Keep in mind the speeds can differ depending on the size of the USB sticks or SSDs with smaller ones more likely being slower than the larger ones.

Perhaps there are other fast options for SanDisk, but the WD site doesn't make it easy to find them and I only took a quick look.

This advice proved just the ticket. I used a flash drive for the bootable installer but tried with a (faster) external SSD for the installation and both Monterey and Ventura installed without a hitch. Thank you for your help.

Thanks for the follow up. I'm glad I was able to help.

Unfortunately those logs are very hard to parse and don't seem to include anything useful....the install just seems to stall.

Did you erase the whole physical destination drive as GUID partition and APFS (top option)?

Are those SanDisk disks actually USB sticks? If so, that is probably the problem. USB sticks are not a good option for installing macOS. They are Ok for the installer, but not the full blown macOS installation. Most of the SanDisk USB sticks are very slow, but even some of the ones with faster writes (about 150MB/s) may still have some issues when booting a full macOS. SanDisk only makes one or two USB sticks where the write speed is about 400MB/s.....I have no idea how it may behave when attempting to boot a full macOS from it, although theoretically it should be more than fast enough, but there may be other things with it that may cause problems.

Is the destination USB drive connected directly to the Mac? It is possible that an adapter, dock, or hub could interfere. Make sure to disconnect all other external devices except for the installer & destination drives. Otherwise I would suggest trying to install it to an actual SSD.