How do I contain my OS purely on a small SSD drive, but store all user data on an additional internal HDD?

What I do is keep my home dir on a separate HDD and my boot and key (often used) apps, prefPanes, login items, etc. on my SSD.

Here's some articles on moving your home dir:

How to Move the Home Folder in OS X – and Why

TUAW Tip: Moving your home folder to another disk (or moving it back)

Move Your Home Folder Off Your SSD Boot Drive in OS X

One thing you need to be aware of is that, as I understand it, when using the apple app store, it will always download to your /Applications folder on your SSD. I wish someone would tell me I'm wrong about this but I am not sure it is.

FWIW, a popular and reliable place to buy SSDs is OWC.

In my opinion you should only move contents into new folders of the like name (aka Music2, Documents2) on the second drive.

Once you start tweaking things out of place, when you update or a glitch occurs, it's rather hard to boot if your user account is on another drive.

There is even software that if you save something to your Documents folder by accident, it can copy it and add it to the Documents2 folder.

I think SyncTwoFolders does this.

I've kept my home dir on a separate drive since 10.1 with no problems what-so-ever. Indeed it's very convenient to do it that way because I keep backups of my boot drive and (and also versions of it if, say going from 10.6.5 to something greater) and of course backups of my drive with my home dir too. It means I can boot from my backup boot drive(s) and my home dir couldn't care less.

You can organize the disk containing your home dir any way you want. You want a Music2, Document2, applications, whatever, by all means do so. If you then have to boot from one of your other boot volumes for some reason everything you need (preferences, Application Support, etc.) is still available and up-to-date as usual because it's the same home dir, not a copy.

Well I guess if the one drive is a SSD, it shouldn't be as two seperate hard drives.

I was looking at the 2x potential for failure.

How does one boot the boot/program drive if the second drive has all the users on it?

Don't you have to leave one user on the boot drive?

Well, I'm the only user on my machine. But I don't see any problem or difference with multiple users. What difference does it make if it's one user or more? I have my machine always prompt for login so I can log into any user I wish. Indeed I do have an additional user defined in my machine strictly for testing without all the additional installations I have defined in my standard account.

As for the 2x failure potential, you can look at that way with two drives involved. Or you could look at as if the boot drive fails it doesn't take the user (or users) with it. And as long as you backup everything the risk is not great. I find the benefits outweigh the risks. And I do backup boot and home dir volumes, for me, every day at 9AM (not using my machine at that time).

One other point, when using an SSD, I really want to try to minimize the use of the SSD as much as I can (within reason of course). So I don't want needless writing to the SSD if I can at all avoid it. And keeping the home dir separate is a simple thing I can do to at least avoid all the potential writing to my home dir. I can't do anything about system operations that write to the boot dir but I don't have to add to it. FWIW, using this line of thought is one of the reasons I have as much ram as I do, i.e., to at least mitigate paging. I also enable noatime on the SSD as well.

Oh, almost forgot. About leaving one user on the boot drive. Additional users, no, but of course root is always on the boot drive it you want to count that.

X423424X wrote:

...root is always on the boot drive it you want to count that.

Naturally, which you have to enable of course or else if your users drives has directory issues you wouldn't have a user to boot into to fix it.

A small home folder - yours - on the SSD is a way to improve performance because it does take a lot of hits and I/O's and while there is the "protect your SSD from writes" drives are also there to be used and as long as it isn't too tiny and has 40GB+ of free space, a month's worth if writes, use it and let the firmware and controller inside do all the agressive background work, even w/o TRIM.

SATA 3.0 specification has called for alll such TRIM and BCG to be part of and built into SATA native command queueing anyway which is something to look forward to, if and when the makers implement in next gen SSDs (and hope it is less trouble and complications as the 2011 series of SATA-SSDs have been).

Putting the /Users on another drive via hard link didn't always work.

Not having a small user makes it harder.

But.... any such 'repairs' etc to your data drive? should be done from your emergency boot volume - another small 30GB you keep handy. And my experience was that the boot drive and not users was an issue unless it was a drive failure type in which case the only cures or fixes were your backup image and restore to a new drive and scratch the old one.

ds store wrote:

Naturally, which you have to enable of course or else if your users drives has directory issues you wouldn't have a user to boot into to fix it.

When I said I always have backups I neglected to mention that one of those backups is always mounted so it is always available to boot from.

The hatter wrote:

A small home folder - yours - on the SSD is a way to improve performance because it does take a lot of hits and I/O's and while there is the "protect your SSD from writes" drives are also there to be used and as long as it isn't too tiny and has 40GB+ of free space, a month's worth if writes, use it and let the firmware and controller inside do all the agressive background work, even w/o TRIM.

As I said I only want my key apps on the SSD and less used stuff off it. If I wanted to fully maximize the disk performance then of course I would keep everything on the SSD. But I prefer the convenience of having a common home dir across any volume I can to boot from.

Putting the /Users on another drive via hard link didn't always work.

I certainly never suggested that and I agree, its problematic.

Not having a small user makes it harder.

As I said above I always have another boot drive available to fall back on I also always have root (and lets not debate the pros and cons about root). And then there's also my unmounted external backups too.

some users tested leaving ~/Library on their SSD - about 1GB worth, and it was worth keepiing it there for performance

you don't want iTunes movies and documents and all the other junk, that is a waste of expensive storage

two wheel drive is always better than mono which is why I have used netinfo manager and such to keep home on 2nd drive, and often that was an array of 2-3 drives

some users tested leaving ~/Library on their SSD - about 1GB worth, and it was worth keepiing it there for performance

I don't like spliting up my home dir even for performance.

two wheel drive is always better than mono which is why I have used netinfo manager and such to keep home on 2nd drive, and often that was an array of 2-3 drives

Huh? Netinfo manager? Not any more! 😕