I needed to change my storage so I used an OWD chip. All went well until the Yosemite changed the structure of the SSD. It hung the machine. Why and can I correct the problem.
What is an "OWD chip?"
Apple changed the default storage type to Core Storage in Yosemite because it is more robust and reliable than the previous solution. It's still an HFS+ volume, but Core Storage is newer technology. It should not have "hung the machine."
William Lloyd wrote:
Apple changed the default storage type to Core Storage in Yosemite because it is more robust and reliable than the previous solution.
Where is this documented by Apple? And my understanding is this conversion is not done on ALL Macs.
It is documented in the OS X Yosemite Core Technologies Overview:
https://www.apple.com/osx/pdf/OSXYosemite_TO_FF1.pdf
Previously, only FileVault encrypted volumes used Core Storage. As of Yosemite, all volumes are Core Storage. There may be a way to force back to the old pre-Core Storage layout, but I haven't investigated how. I can't see that there would be any reason to do that.
Edit: It may be that only Macs that support AES-NI (this is a feature of more recent Intel chips) auto convert to Core Storage. These Macs came in about the time of Lion, so 2011 and later Macs? A good resource is here: http://www.hcsonline.com/support/blog/entry/yosemite-auto-converts-to-core-stora ge
Thanks for the PDF reference. No idea why Apple employees keep this hush-hush.
The way to revert back to native file format is via the following Terminal command as long as the Logical Volume is Revertible. Portable Macs (laptops) get converted. But not all Macs do. I only have the word of Apple employees from beta testing.
diskutil cs revert <Logical Volume's Disk: or UUID>
William Lloyd wrote:
Edit: It may be that only Macs that support AES-NI (this is a feature of more recent Intel chips) auto convert to Core Storage.
From an Apple employee:
The installer converts to Core Storage when:
I guess they consider the Mini portable because it made my Mini a core storage format.
It is a replacement SSD chip by a company called OWD. The chip is 256Gig compared to the 128 Gig on the machine I purchased.
I know Apple frowns on this upgrade but since the update functioned correctly for several hours and only locked up after going to standby overnight it appeared to their OWD's technical support that this change affected the performance.
Question: Would Yosemite change the file structure when installed or does it do it when the user is not active (like standby)
Maureen macAir wrote:
It is a replacement SSD chip by a company called OWD. The chip is 256Gig compared to the 128 Gig on the machine I purchased.
Question: Would Yosemite change the file structure when installed or does it do it when the user is not active (like standby)
You mean OWC which is Other World Computing (Macsales.com).
Do you mean when you replaced your SSD with the larger one and re-installed Yosemite, Yosemite created a CoreStorage - Logical Volume Group formatted disk? My prior post explains when the Yosemite install changes from HFS+ format to CoreStorage. If it is this format type, it will work just fine and should not hang as William Lloyd mentioned.
What year and model is your Mac? Is it a Macbook Pro Retina (2012-2013) or a different Mac?
The change to Core Storage does not affect the file structure in any way. I suspect OWC is pointing you in the wrong direction.
why did disk change to "core storage"
