Date: Fri, 16 Jul 2004 12:38:50 +0200 (CEST) From: Wojciech Puchar <wojtek@tensor.3miasto.net> To: Nikos Vassiliadis <nvass@teledome.gr> Cc: freebsd-questions@freebsd.org Subject: Re: FreeBSD beginner (NetBSD advanced) Message-ID: <Pine.NEB.4.60.0407161236400.21969@chylonia.3miasto.net> In-Reply-To: <200407161045.35953.nvass@teledome.gr> References: <Pine.NEB.4.60.0407152019430.24734@chylonia.3miasto.net> <Pine.NEB.4.60.0407152340010.21629@chylonia.3miasto.net> <200407161045.35953.nvass@teledome.gr>
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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. > does FreeBSD deallocate pages that are unused. NetBSD does not. if you create 100MB file on mfs and delete it, VM size of mfs is still over 100MB. while it will get swapped out it's a kind of nonsense IMHO >> 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 have too. anyway softdeps is big speedup. i tried async and doing sync every 5 seconds. looks good. > I think you will miss ALTQ. There is a patch for FreeBSD-4.8 at Kenjiro's page. > i read manual page about ipfw yesterday. i think i will not miss :) > 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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