Date: Fri, 24 Jan 2003 19:15:28 -0500 From: "Craig Reyenga" <creyenga@connectmail.carleton.ca> To: <Kevin_Stevens@pursued-with.net> Cc: <freebsd-questions@freebsd.org> Subject: Re: Filesystem tuning parameters Message-ID: <001301c2c406$ddf08310$0200000a@sewer.org> References: <20030124160148.R12356@babelfish.pursued-with.net>
next in thread | previous in thread | raw e-mail | index | archive | help
You're right, dedicating that much space to nothing is pretty pointless. What I did was I edited /usr/src/sys/ufs/ffs/fs.h and changed: #define MINFREE 8 to #define MINFREE 0 and then recompiled the kernel and set my /home partition to use 0% free space with tunefs. Now I get to use every last block, and it goes quite fast, until I truly do run real low on free space. I believe this is the way out, but I could be out to lunch on this one. Hope this helps. -Craig ----- Original Message ----- From: "Kevin Stevens" <Kevin_Stevens@pursued-with.net> To: <freebsd-questions@freebsd.org> Sent: Friday, January 24, 2003 19:03 Subject: Filesystem tuning parameters > I have a confusion about apparent conflicts between the minfree setting > and time/space optimization. > > Per the manpage: > minfree - > Specify the percentage of space held back from normal users; the > minimum free space threshold. The default value used is 8%. > This value can be set to zero, however up to a factor of three in > throughput will be lost over the performance obtained at a 10% > threshold. Settings of 5% and less force space optimization to > always be used which will greatly increase the overhead for file > writes. > > space/time - > The filesystem can either try to minimize the time spent allocat- > ing blocks, or it can attempt to minimize the space fragmentation > on the disk. Optimization for space has much higher overhead for > file writes. The kernel normally changes the preference automat- > ically as the percent fragmentation changes on the filesystem. > > I have a large (120GB) drive dedicated to data storage. I don't want to > commit 10% (12GB) of space to free space, and I don't need nearly that > much to avoid overflowing the volume. However, I want to maintain time > optimization. When it says that "settings of 5% and less force space > optimization to be used", is that still the case when you specify time > optimization?? > > Also, why is "up to a factor of three in throughput" lost over the 10% > setting? Is that another allusion to space optimization going into > effect, or is there something else happening? I guess I don't understand > the ramifications of the minfree setting. Any suggestions or references? > > Thanks! > > KeS > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-questions" in the body of the message > To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?001301c2c406$ddf08310$0200000a>