Path: utzoo!utgpu!attcan!uunet!lll-winken!lll-tis!ames!haven!mimsy!tank!ncar!boulder!bernard
From: bernard@boulder.Colorado.EDU (Bernie Bernstein)
Newsgroups: comp.sys.next
Subject: Re: Mach features? (Re: Paging and swapping to a removable disk?)
Message-ID: <4200@boulder.Colorado.EDU>
Date: 20 Oct 88 23:48:34 GMT
References: <12670001@eecs.nwu.edu> <3924@encore.UUCP> <3352@pt.cs.cmu.edu> <73838@sun.uucp>
Sender: news@boulder.Colorado.EDU
Reply-To: bernard@boulder.Colorado.EDU (Bernie Bernstein)
Organization: University of Colorado, Boulder
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In <73838@sun.uucp> ram@sun.UUCP (Renu Raman) writes:
>In <3352@pt.cs.cmu.edu> ralphw@ius3.ius.cs.cmu.edu (Ralph Hyre) writes:
>>In <3924@encore.UUCP> bzs@xenna (Barry Shein) writes:
>>>>Does Mach (on a NeXT, at any rate) do memory swapping to disk?
>>>>If so, what does it use for the swap area when the laser disk is out?
>>>I'll stick my neck out and say that I don't believe that you'll be
>>>able to remove the optical disk if that's what you're paging and
>>>swapping to 
>    What if you can swap over the network?
>    I thought that was possible in Mach. 
>    change your swap area to the big server's filesystem that is
>    remote mounted and continue to swap your disks as you please.

Oh yeah, and let one CPU manage the paging for the entire network.
Then we can see some real wild thrashing.:->

I think what is necessary is paging to the local disk.  It should be a
fast one, so if the seek rates on the optical disk are above 30ms, then
perhaps a Wren (16.5ms) or some other traditional hard disk should be used.
Otherwise, we can keep the optical disk in and go along with Ralph's
hypothesis:  don't let the disk out unless we're ready ...

- Bernie



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Bernie Bernstein                        bernard@boulder.colorado.edu