Date: Mon, 22 Nov 1999 22:41:29 -0800 (PST) From: Matthew Dillon <dillon@apollo.backplane.com> To: Joe Greco <jgreco@ns.sol.net> Cc: abial@webgiro.com (Andrzej Bialecki), freebsd-hackers@FreeBSD.ORG Subject: Re: Non-standard FFS parameters Message-ID: <199911230641.WAA02469@apollo.backplane.com> References: <199911230601.AAA04318@aurora.sol.net>
next in thread | previous in thread | raw e-mail | index | archive | help
:What's the recommended way to reduce the number of cylinder groups a bit?
:-c's maximum limit is affected by combinations of -b and -i, possibly some
:others. PHK was talking about new, more sensible values for filesystem
:parameters, but I don't know what happened. I just think it's a bit silly
:to go generating hundreds of cg's for a 34GB unit... and this _with_ the
:max -c setting of 26 (for this fs).
:
:/dev/vinum/rn8: 63700992 sectors in 15552 cylinders of 1 tracks, 4096 sectors
: 31104.0MB in 599 cyl groups (26 c/g, 52.00MB/g, 256 i/g)
:super-block backups (for fsck -b #) at:
: 32, 106528, 213024, 319520, 426016, 532512, 639008, 745504, 852000, 958496,
:
:... Joe
:
:-------------------------------------------------------------------------------
:Joe Greco - Systems Administrator jgreco@ns.sol.net
Well, -i doesn't effect c/g any where near as much as -b does. Try
bumping the block size up to 16K and use '-c 999' and see what newfs
tells you the max c/g is. -b 16384 -f 2048 -c 999. On my test it let
me do 89 c/g.
As we already know, non-standard block sizes will create problems under
stable and may create them under current. I believe I have fixed the
bugs under current (in getnewbuf()) but since no comprehensive testing
has been done you still have a lockup risk. Work on the VM system
mainly by Luoqi a few months ago fixed the buffer corruption bugs,
so only lockup bugs should be left.
-Matt
Matthew Dillon
<dillon@backplane.com>
To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?199911230641.WAA02469>