I have had a nMP base mode for about three weeks. It comes with 256 g of SSD, which implies I have to store my data on external drives.
Compressor uses a Cache in the user/library, so if I want to use that program, I need to move my user directory to an external disk. If I use the side panel to manage my data then I also have to move the user to an external disk, unless I want to dig up some 30 year old unix skills and map the directories to an external drive.
I just imported 8TB of videos into FCPX. So I manage a lot of data. I just bought a 20 TB read5 thunder bay raid five drive and partitioned with a 2TB home drive and a 13 TB videos storage drive.
The first issues, is there is no easy way to move a user directory from one drive to another. There are unix commands to accomplish this, I could not get it to work by just copying the user folder to the new drive and relinking it through the user system preferences panel. I just had to rebuild the user and copy my user data over.
Time machine does not work very well with Video libraries. I prefer to back up my users data with time machine, and my video data bases independently. By partitioning a 2gb home drive I can use time machine and airport to back up my system and user files and an independent program to back up my video files.
I built my raid drive with soft raid installed by a root users on the SSD drive. This way I could insure the files to control the raid were not store on the raid user. When testing the raid by unplugging drives hot and rebuilding the raid, I had no problems with the user on the raid drive.
While I bought my nMP as an impulse buy, It was clear by the marking this unit is designed to support external storage via thunderbolt connections. This is a different design philosophy than the tower designs. I ponied up for the a professional grade computer and I expect professional grade tools and support with it.
If the product does not support external users, they have misrepresented the product. As a professional, I might want a different login account and storage system for each of my customers. I might have to take my user and plug him into different mac systems. There are a lot of valid reasons to support users on external drive.
I have not found anything close to a professional white paper on system design guidelines from apple for the nMP and to be honest, I am a little concerned about their long term support for the professional world.
I also can see that using raid technology with SSD is nuts. If there is a new SSD/thunderbolt technology that will replace raid drives, I can accept the short term issues and work around them. As a professional, I need to understand what their long term plans and directions are to keep my system design correct.
I would assume if I have to rebuild my raid from a complete failure, should be able to recover it from time machine. I have not tested it, but this is the stuff that should be sold in a professional level machine. This was one of the reasons i move to apple couple of years ago, and why I bought the nMP.
I also use Parallels Desktop for my dos programs I have the system image on the raid drive. That seems to work fine also.
I don't see any logic in having the system files on an external drive with the nMP. It made sense in a hard drive (DOS) world but in an SSD environment it makes far more sense to keep the system files local and the user/data on external storage. Raid makes no sense at all in an SSD world. but it is clear we on on the front edge of that movement.
The big advantage for me is to be able to reinstall the system files independent from the user data. I only tried it once and it was not as clean as I would like, I think I had to rebuild the user instead of relinking it, but that was not a huge deal compared to trying to recover from with my mess of data on a system drive.
I am impressed with the design of the machine, it has a lot of potential, external GPUs, External thunderbolt storage controllers, we will just have to see where it ends up.
You did put a lot of points on the table. However, in a context of a *nix system, the following rule of thumb should be taken under consideration: user home, user data, and system files should be handled separately (all 3 of them).
To clarify the above, a valid setup would/should be:
1. The users home folders in the internal storage. Considering the above, no other data should exist in there, except the user's application preferences. So, no much space should be required for this.
2. The user data on an external storage. That's the main content, hence that's where the space will be occupied. Applications should be configured to use the external storage. If needed, you could also protect the users' data from each other. After all, it's a unix, so it is built over the user isolation concept out of the box.
3. System files (OS files) should also be on the internal storage.
In other words, let the OS-related files/directories (system files and user home directories) on a unified always-available trusted storage (internal) and just handle the data externally, as you like. After all, these are the data that will take all the real space.
Concerning the backup/recovery, I'd just use Time Machine for the system files (operating system and user homes), but if the system serves more than one user, I'd only use TM to restore OS files. Then, the user accounts could be restored individually, using the Migration Assistant as needed (using the TM backup of course). I'd use a different externalized strategy for the backup of the user data (the ones on the external storage) and would not bother the operating system with this effort.
I think the above scenario is the most "clean" setup for this. Another variation of the above, could be using symbolic links for the users homes to the external storage. But, just in case, even then I'd keep the administrative account's home in the internal storage.
