Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!ames!sun-barr!apple!oliveb!tymix!cirrusl!sun505!dhesi From: dhesi@sun505.UUCP (Rahul Dhesi) Newsgroups: comp.unix.wizards Subject: swap partitions vs files Message-ID: <858@cirrusl.UUCP> Date: 16 Sep 89 00:45:41 GMT Sender: news@cirrusl.UUCP Reply-To: dhesi%cirrusl@oliveb.ATC.olivetti.com (Rahul Dhesi) Organization: Cirrus Logic Inc. Lines: 25 This question is probably specific to SunOS 4.x, unless 4.3BSD-tahoe has this feature too. SunOS 4.x allows you to specify not only a disk partition for swapping, but also a file created with mkfile(8). If I were doing it, I would have the kernel map the blocks in the file to a range of physical blocks on disk just once, and then do all swapping directly to physical blocks on disk. This would make swapping to a file as efficient as swapping to a partition. (My concern is purely with disks local to a Sun workstation, not with swapping over a network.) On the other hand, if swapping to a file involves some run-time mapping, it will be slower than using a swap partition. The Sun manuals are silent on the issue of performance. Question: Are the two equally efficient, or is swapping to a file less efficient? Please post or email your response as you consider appropriate. -- Rahul Dhesi UUCP: oliveb!cirrusl!dhesi