On Feb 24, 2004, at 11:25 AM, Mickey S. wrote: Hello, I am new to the Darwin / MacOS world and I am looking for some guidance. For starters I have heard any number of pros and cons about the swap file system used in Darwin. I understand the basics of the Dynamic Pager system ,but I am wondering why there appears to be a lack if support to dedicated swap partitions. Is this a limitation of XNU? or is this to make Apple's end users happy I.E. when they buy a 150G disk they don't see 149G available. ;) . It is not a limitation of XNU, if fact no limitation exists, one can create swap partitions and target the pager at it. Of course doing so is not a normal configuration or support by Apple (at least I don't think Apple supports it). If you want to do it do it... for more information on the dynamic page try "man dynamic_pager". Just understand that is not normal and later updates make break your redirected swap. Having a swap partition will likely greatly limit how big the swap file(s) can grow and hence limit what the system can do before running out of virtual memory backing (which often leads to crashes...). So slicing off a percentage of the relatively huge disks one gets in systems today can be counter productive. Some folks will state that having a swap partition reduces the chance of file / swap file fragmentation. It does but the data in the swap files is already greatly fragmented (for various obvious reasons) as is the page in/out pattern and that is likely to be more of an issue then fragmentation of swap file itself. Additionally if file fragmentation of the swap is some how an issue, your system is already greatly hindered by the swapping taking place, it will be the least of your issues. Now targeting an independent device for swap can make sense for some folks / environments. -Shawn _______________________________________________ darwin-kernel mailing list | darwin-kernel@lists.apple.com Help/Unsubscribe/Archives: http://www.lists.apple.com/mailman/listinfo/darwin-kernel Do not post admin requests to the list. They will be ignored.