So, I started thinking about moving my movie collection from DVDs to a hard drive. HDDs are so cheap right now. You can get 2T disk for about $200. And it will fit most of my 500 movies if I simply convert them to ISO files. ISO format is very convenient, because you can mount it with one click in Mac OS (I use Mini as my media center) and then just run DVDPlayer.

In Windows world DVDShrink will create ISO from DVD and it's free. In MacOS I don't think there is free alternative program. However I found combination of two things that does exactly that:

1. MacTheRipper. Rip your DVD into a folder (with VIDEO_TS and AUDIO_TS underneath).

2. And then use this command in Terminal to create ISO file:
hdiutil makehybrid -udf -udf-volume-name MYDVD1 -o mydvd.iso DVD_FOLDER

Make sure DVD_FOLDER is a parent folder for VIDEO_TS folder.