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Date: Wed, 31 Jan 1996 15:13:07 -0700
From: Nate Williams <nate@sri.MT.net>
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To: Jake Hamby <jehamby@lightside.com>
Cc: freebsd-hackers@FreeBSD.org
Subject: Swapping (was Re: Good news -- pipe stuff)
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> 
> Another thing to look into, although I don't have a benchmark on this, but
> FreeBSD has a nasty tendency to "bind" during heavy VM/disk activity.  I
> don't know if this is because the IDE driver is CPU intensive, or if this
> affects people (to a lesser extent) with SCSI drives.

This is an IDE thing.  Basically, the system must uses lots more CPU and
is much less effecient than using the SCSI drivers.

> It's just that when
> the system starts paging out to disk, activity in other windows freezes up
> too.

There's nothing else the system can do when it's swapping. :)

> Speaking of VM, I set up a system with only 8MB of RAM running FreeBSD, 
> and even though we made a 24MB swap partition, occasionally it fills up.  
> Both boxes are running 2.1.0-RELEASE.  If it is not too difficult, I 
> would be REALLY grateful if we could add functionality to add swapfiles 
> and swap partitions to a running system.

You can.  See 'man vnconfig'.

> Even better would be the 
> ability to remove the swapfile without rebooting.  Linux (and most 
> SVR4's) have had this functionality for a LONG time.

Are you *SURE* you can remove it w/out rebooting on Linux.  AFAIK, it's
not possible, although I do know my Solaris box can delete swapfiles
(although I have yet to have an occasion to do so, since the Solaris box
always wants more swap than I have disk space. :)


Nate