Create and use a swapfile on another disk

nbar > There are better uses for this drive then using it for your swap space.

Such as?

I admit this is more or less of an experiment. Normally I would keep the system disk internally and add the ThunderBolt drive as the user partition, but since it is so amazingly much faster I don't think that is a win, in any case I am just trying to test it. If I am getting swapping, and I am at times, then if the swapping does not go over the ThunderBolt it would theoretically anyway free up I/O to that disk.

nbar > You will always have a swap file generated upon boot even if you have no page-outs.

That is correct as I understand MacOS.

I envision the solution as consisting of a script I can run after boot that creates or detects a swapfile on my internal drive, turns on swapping to it, stops swapping to the external system drive, and if necessary deletes the swapfile on the external system drive. This used to be really easy in systems like IRIX or Solaris and even Linux.

Swapping has changed a lot in UNIX. It used to be you needed a full partition on your disk as swap, then systems began to be able to swap to files. This should be easier than ever before, but thanks to most computer companies things are instead getting harder to do in the name of "helping" the customers, or making support easier. UNIX has pretty much been ruined by too much designed in complexity and obfuscation and not enough documentation.

michael black > If your device is not swapping to disc in the first place, than having a bigger and/or faster swap area is truly pointless.

Michael, whether what I want to do is pointless or not, if you do not know how, it's fine, you don't need to reply, right? If you want to add value to your reply instead of just being negative you might talk about how to measure this. Clearly the question is about "if or when" the system begins to swap, not about whether it is or not.

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Maybe I am too sensitive to some of these answers because a long time ago in a galaxy far away I used to do system, network and customer support and when peolpe got questions they had no idea how to answer they would often use the tactic of trying to make the "customer" feel stupid for asking the question. This was something I thought did not help people, did not help the company and in fact made customers dislike the company and not trust them and was not worth of a good support engineer. Here people do not have to answer if they do not know, and they are not being paid, except I guess in point status, so these kind of answers provoke me a little bit.

Frank, I know it is fashionable to give unsolicited advice instead of answering the question, but this is not a question of paging, which if you cared to read the question you would have caught ... it is a question or redirecting I/O ( i.e. swapping ) away from the system disk which is very fast, but not infinitely so, over to another disk which is not getting any use at all. I've read quite a few answers on this, and many of them go for the don't do that non-answer, and it's not helpful, except as an addenda from someone who knows how to do and qualifies their answer. Thank you.

By the way, I have 16GB RAM on the system. Never enough. ;-)

Nbar ... I wish I did have an SSD, but I don't. My Mac is 27" but several years old now, with only a regular 1TB drive for the system drive. If I could get the system to swap to that drive I think it would be a win as there would be less I/O to the root disk, particularly when doing video or other I/O intensive stuff.

I'm thinking you did not read what I wrote about this you did not acknowlege that I am using an external disk for my system disk ... a Thunderbolt 8TB WD MyBook drive.

> Actually I don't see the point of posting a long and detailed answer to a question where no actual issue or problem even exists in the first place.

So you have nothing better to do when you don't get the question, don't know the answer, why post?

No problem .... I just wish I could afford an 8TB SSD! ;-)