Date: Wed, 21 Mar 2001 10:28:37 -0800 From: Alfred Perlstein <bright@wintelcom.net> To: Matt Dillon <dillon@earth.backplane.com> Cc: "Michael C . Wu" <keichii@iteration.net>, Rik van Riel <riel@conectiva.com.br>, Peter Wemm <peter@netplex.com.au>, izero@ms26.hinet.net, cross@math.psu.edu, grog@FreeBSD.org, fs@FreeBSD.org, hackers@FreeBSD.org Subject: Re: tuning a VERY heavily (30.0) loaded s cerver Message-ID: <20010321102836.N12319@fw.wintelcom.net> In-Reply-To: <200103211817.f2LIHR416007@earth.backplane.com>; from dillon@earth.backplane.com on Wed, Mar 21, 2001 at 10:17:27AM -0800 References: <200103211114.f2LBE0h57371@mobile.wemm.org> <Pine.LNX.4.21.0103211328310.9056-100000@imladris.rielhome.conectiva> <20010321120620.A932@peorth.iteration.net> <200103211817.f2LIHR416007@earth.backplane.com>
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* Matt Dillon <dillon@earth.backplane.com> [010321 10:20] wrote: > > :B) Added 3gb of swap on one drive, 1gb of swap on a raid volume > : another 1gb swap on another raid volume > :C) enabled vfs.vmiodirenable and kern.ipc.shm_use_phys > : > :-- > :+-----------------------------------------------------------+ > :| keichii@iteration.net | keichii@freebsd.org | > > I'd reduce that 3gb on that one drive to 1gb. The kernel > allocates a bitmap for 4 * (largest_swap_partition), i.e. > it will allocate a bitmap for 3gb x 4 = 12 gb worth of swap, > even though you only have 5. If you reduce the 3gb to 1gb, then > the kernel will allocate a bitmap for 1gb x 4 = 4gb worth of swap, > using 1/3 the memory for the bitmap. Each page of swap eats 2 bits of > memory for the bitmap so we aren't talking about a huge > amount of memory, but it's worth doing. Hey, talking about large amounts of swap, did you know that: 4.2-STABLE FreeBSD 4.2-STABLE #1: Sat Feb 10 01:26:41 PST 2001 has a max swap limit that's possibly 'low': b: 15912412 0 swap # (Cyl. 0 - 990*) c: 17912412 0 unused 0 0 # (Cyl. 0 - 1114*) If I made b == c, then i couldn't swapon it. Don't ask why I have that much swap, I just needed a bunch on a dedicated disk. :) -- -Alfred Perlstein - [bright@wintelcom.net|alfred@freebsd.org] To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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