"Updating database of binaries" step very slow under Yosemite?

[René J.V. Bertin]

> In at least some cases, the Yosemite installer wraps HFS+ volumes up into a Core Storage Logical Volume Group, and they become Core Storage Logical Volumes.
>
> http://arstechnica.com/apple/2014/10/os-x-10-10/2/#diskutil-list

that's the part I was wondering about ... and in what unexpected ways
it could mess up one's partition table ...

R.