Comments on: offload Mac OS X swap with dynamic_pager and an SDXC card

By: Mike

Mike — Fri, 05 Nov 2010 18:47:28 +0000

Has anyone found the OSX parameters/switches (possibly to dynamic_pager) thats tells it to not swap out processes unless it absolutly has too. this is in response to the OS swapping not-used programs out to create memory that may be needed. this has the effect that when I come into work in the morning, the machine takes a while before all the apps are running again (due to these apps being swapped out overnight).
man dynamic_pager shows an umimpl;emented -P option (for priority). Im using leopard (not snow leopard).

By: Daniel

Daniel — Sun, 01 Aug 2010 19:43:47 +0000

I’m rather surprised that Apple has not extended dynamic_swapper to allow multiple swap locations and implemented the “-P” (priority) option; I have used a similar facility on another Unix-like OS that allowed the addition of swap areas after the swapper has been started; if the priority of a new swap area is higher, it will be used in preference to the older swap areas, but data swapped out to those earlier areas remains in place until it’s made invalid (swapped in and reaped or swapped in and modified); If the preferred swap area fils up, the lower-priority swap areas are used (in order of priority, randomly within a priority level). This would allow a device that may or may not be present be added at the user’s “whim” and then have swap activity automatically shift to that device.

By: chet

chet — Sat, 24 Jul 2010 17:56:37 +0000

Oh nice! That’s awesome. Thanks for checking that one out My wife has an ExpressCard slot.. maybe I’ll try that out sometime

By: Chris

Chris — Sat, 24 Jul 2010 17:46:53 +0000

I found a solution for those without build in SD slots. The previous MBPs had Express/34 slots.

This should do the trick, and at 8GB should be plenty of swap space:
http://shop.transcendusa.com/product/ItemDetail.asp?ItemID=TS8GSSD34E-M

Some test show that you can get of 32mb/s read and 16mb/s write speeds onto the Express/34 card.

By: Tweets that mention offload Mac OS X swap with dynamic_pager and an SDXC card « sidenotes -- Topsy.com

Sat, 24 Jul 2010 06:59:31 +0000

[...] This post was mentioned on Twitter by Chet Nichols, Chris Klosowski. Chris Klosowski said: RT @chet: blog update: offload Mac OS X swap with dynamic_pager and an SDXC card – http://bit.ly/bFVQYH [...]

By: Chris

Chris — Sat, 24 Jul 2010 06:30:15 +0000

Great idea Chet.

I have the model MBP prior to the redesign with the SD slot, but who knows, that could change soon . If it does I’ll give this a shot.

I’d write a bash script to ‘swap’ two versions of the plist file so if I did need that slot for use, I could easy put my swap back onto the HD, and when done, switch back to the SDXC.