Date: Fri, 16 Jul 2004 10:45:35 +0300 From: Nikos Vassiliadis <nvass@teledome.gr> To: Wojciech Puchar <wojtek@tensor.3miasto.net> Cc: freebsd-questions@freebsd.org Subject: Re: FreeBSD beginner (NetBSD advanced) Message-ID: <200407161045.35953.nvass@teledome.gr> In-Reply-To: <Pine.NEB.4.60.0407152340010.21629@chylonia.3miasto.net> References: <Pine.NEB.4.60.0407152019430.24734@chylonia.3miasto.net> <40F6DAC9.9020403@mac.com> <Pine.NEB.4.60.0407152340010.21629@chylonia.3miasto.net>
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I have used a single 256MB mfs on FreeBSD for months without any problem. I was not doing heavy IO on it, it was used in a /tmp fashion and most of the time was swapped out, going down to 8MB resident size at times. > softdeps in NetBSD is very buggy. putting very high load like deleting > huge tree or unpacking it easily triggers DDB with ffs_something panic :( I have the feeling that NetBSD without softdeps performs much better than FreeBSD. I can live without them on NetBSD. I think you will miss ALTQ. There is a patch for FreeBSD-4.8 at Kenjiro's page. NikV On Friday 16 July 2004 00:50, Wojciech Puchar wrote: > > Wojciech Puchar wrote: > >> i installed FreeBSD once to do quick performance tests, and at least in > >> disk I/O and fair scheduling it's MUCH better (tested 4.10 and 5.1). > > > > It's nice to be welcomed by higher performance when you switch OSes. :-) > > while high performance is always cool, stable performance is even more > important under load. I mean if i do 5 things it shouldn't slow down 100 > times. > > in NetBSD especially if you start large file copying whole system slows > down terribly. not true with FreeBSD. > > softdeps in NetBSD is very buggy. putting very high load like deleting > huge tree or unpacking it easily triggers DDB with ffs_something panic :( > > >> my questions: > >> > >> 1) what is Buf and Cache in top exactly? why buf on 96MB machine gets to > >> near 20MB and never goes down? it's almost 1/4 of memory size. > > > > Cache: number of pages used for VM-level disk caching > > Buf: number of pages used for BIO-level disk caching > > can you explain more? (or redirect me to URL about it) > > is all things double-buffered?!!!!!! it would be lots of memory traffic. > > > BTW is mfs usable and stable in FreeBSD? and does it make real sense? > > in NetBSD mfs is terribly unstable. especially large mfs disks easily > crash things. > > >> 2) can i compile kernel with -march=pentium,pentium[234] -O2 > >> optimization? in NetBSD 2.0 doing -march=pentium produces kernel that > >> doesn't boot at all, just resets. > > > > If you want to tune your system, tweaking the options from GENERIC by > > removing at least: > > > > cpu I386_CPU > > cpu I486_CPU > > did this. > > > ...will probably result in the greatest improvement, along with disabling > > WITNESS and such if using -CURRENT. See "man tuning". > > oh - i never did it... > > > Using -march=pentium is likely to be worthwhile (assuming you don't have > > a > > with heavy CPU-bound userland binaries i measured 10-25% gain. > > > 386 :-), higher than that may run into problems. Higher optimizations > > than -O are not supported, although work is underway to fix the remaining > > code issues (mainly in libalias used by NAT), as I understand. > > > > If you want to try -O2, give it a shot, but you might consider using > > either "-Os" rather than "-O2", or try "-O2 -fno-strict-aliasing". > > why -Os? it makes slower but smaller code? > > will lower memory traffic/better cache hitting give more gain than it's > lost because of slower code. > > >> 3) how can i disable compiling, using etc.. all that LKM (KLD) stuff? > >> > >> i really prefer one static kernel. > > > > Read the handbook on building the kernel. > > what i missed? > > i already built a kernel, found how to disable modules but all kld stuff > is still compiled in! > > yes i can just do rm *.ko but removing kld from kernel would be even > nicer. > > >> 4) is IPv6 working well? (i mean no crashes etc...) i will get real IPv6 > >> zone allocation soon and want to use it. > > > > IPv6 seems to work well, yes. > > > >> 5) what is used in FreeBSD for traffic management. NetBSD has altq - > >> please just give me a name i will RTFM. > > > > If you want to use that, ipf/altq should be available in -CURRENT. > > Otherwise, ipfw & dummynet is another choice. > > > >> 6) how to turn using serial port as console on i386? my home machine is > >> headless, i'm using X terminals to access it. > > > > See the handbook. > > > >> 7) does FreeBSD support 2 CPUs on i386? > > > > Sure. See the SMP section of the kernel config file. > > > >> should i go to 4.10 or better 5.2.1? stability is really important to > >> me. > > > > 4.10, unless there's a feature from -CURRENT that you don't want to live > > without. > > i don't think it is unless 4.10 has: > > 1) multiCPU > 2) traffic shaping > 3) nat > 4) firewalling > 5) IPv6 > 6) tun device > > i don't think i need anything more > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "freebsd-questions-unsubscribe@freebsd.org"
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