From: Simon W. <si...@zy...> - 2005-04-08 14:49:49
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Hi, been lurking on IRC etc trying to get my first UML instances up and stable. Was running Debian testing on host, with the various Debian UML packages loaded from the other versions, and the Debian stable file system from the usermodelinux.org site. Had a lot of problems getting networking working, and stable, despite considerable firewall, and some bridging experience. With a vanilla 2.4.27 Debian kernel, and; Linux version 2.4.26-3um (root@mizar) (gcc version 3.3.4 (Debian 1:3.3.4-11)) #2 Wed Sep 8 18:07:31 PDT 2004 I failed to get a stable networking setup - problem was that the UML instance would hang (or sometimes just the networking, until the tuntap uinterface was taken out of the bridge, reset, and brought up again). This would happen frequently, and everytime "nslookup" was run in the UML. Running "strace nslookup" in the UML worked fine, running strace against the UML produce 69MB of indecipherable loopings and a UML so slow I wasn't sure if it had hung or not <sigh>. Anyway it seems that switching to a host kernel 2.4.25 with the SKA patch in (as per one of the Debian stable UML "HOWTO"'s) solved the problem. I assume some sort of race condition, that the SKA patch addresses. Seems at least with that combination the SKA patch is mandatory for stability of the UML. However it isn't clear to me that the SKA patch is "mandatory" from my initial reading of the documentation - desirable yes - but it looks to me like it is mandatory. I was also a bit disappointed some of the documentation was so "dated", lots of it, much of it very good, but contradictory due to age, and a lot refers to old stuff that is of little current interest. I don't know enough yet to write new documentation, but I'd happily put in a little time to "tidy up" some of the existing documentation. |
From: Jelle B. <uml...@ni...> - 2005-04-08 15:03:36
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On Friday 08 April 2005 16:49, Simon Waters wrote: > Hi, > > been lurking on IRC etc trying to get my first UML instances up and stable. > > Was running Debian testing on host, with the various Debian UML packages > loaded from the other versions, and the Debian stable file system from the > usermodelinux.org site. Did you try a 2.6 kernel? you only mention 2.4 kernels, most development is on 2.6 I guess. [...] -- with kind regards, Jelle Booomstra PS: where can I volunteer to have that tejas networks adres removed from the list? |
From: Blaisorblade <bla...@ya...> - 2005-04-08 17:22:49
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On Friday 08 April 2005 17:04, Jelle Boomstra wrote: > On Friday 08 April 2005 16:49, Simon Waters wrote: > > Hi, > > > > been lurking on IRC etc trying to get my first UML instances up and > > stable. > > > > Was running Debian testing on host, with the various Debian UML packages > > loaded from the other versions, and the Debian stable file system from > > the usermodelinux.org site. About SKAS: it's not mandatory, however since almost everybody uses SKAS mode, TT mode is frequently non-debugged. It's not abandoned, when mode-specific bugs are reported they usually get fixed soon. > Did you try a 2.6 kernel? you only mention 2.4 kernels, most development is > on 2.6 I guess. What is more important, is that 2.6 kernels are usually more stable *at all*. We aren't yet rewriting from scratch big parts of code, we are instead gradually and gradually fixing it more and more. There are some bigger changes, which are well tested anyway. Especially, try either 2.6.11-bs3, 2.6.11-bs1, or 2.6.9-bs7 (in this order). The last one is known to be a bit unstable in TT mode, however (where "a bit" means "install Gentoo to notice" or something like that). -- Paolo Giarrusso, aka Blaisorblade Linux registered user n. 292729 http://www.user-mode-linux.org/~blaisorblade |
From: Simon W. <si...@zy...> - 2005-04-11 09:04:31
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On Friday 08 Apr 2005 6:28 pm, Blaisorblade wrote: > On Friday 08 April 2005 17:04, Jelle Boomstra wrote: > > On Friday 08 April 2005 16:49, Simon Waters wrote: > > > > > > Was running Debian testing on host, with the various Debian UML > > > packages loaded from the other versions, and the Debian stable file > > > system from the usermodelinux.org site. > > About SKAS: it's not mandatory, however since almost everybody uses SKAS > mode, TT mode is frequently non-debugged. It's not abandoned, when > mode-specific bugs are reported they usually get fixed soon. Well looks like there is a bug, but not sure how to report it other than the kernel versions as before. > > Did you try a 2.6 kernel? you only mention 2.4 kernels, most development > > is on 2.6 I guess. > > What is more important, is that 2.6 kernels are usually more stable *at > all*. > > We aren't yet rewriting from scratch big parts of code, we are instead > gradually and gradually fixing it more and more. There are some bigger > changes, which are well tested anyway. > > Especially, try either 2.6.11-bs3, 2.6.11-bs1, or 2.6.9-bs7 (in this > order). The last one is known to be a bit unstable in TT mode, however > (where "a bit" means "install Gentoo to notice" or something like that). I tried a build of 2.6.11 (stock kernel) with the ARCH=um, and also one from someone on the IRC channel, these kernels started some tasks on the 2.4.27 based host, but I got some errors and nothing that resembled a working UML. At this point I decided trying 2.6.11 was a step backwards from where I was and found the "Debian Stable HOWTO" with the SKA patched 2.4.25 and found that worked. I can investigate the errors on the 2.6.11 kernel and rebuild with the later patches - I was unclear as to whether I should need a host kernel patch, and whether I could run 2.6 UMLs only on 2.6 host kermels, so finding something that worked was a higher priority than finding out why it didn't work. Of course now it works I have more time - if only waiting for the upgrade from Woody to Sarge to run - now I've decided Woody really is too old for what I want to do. Thanks, Simon |
From: Ian M. <im...@gm...> - 2005-04-08 18:55:57
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Hi there for what it is worth here is the setup I'm running which works just fine for 2.4.x as my setup sounds similar to you Host kernel 2.4.27 on Debian Woody. gcc 2.95.4 Guest kernel 2.4.27 patched with: http://prdownloads.sourceforge.net/user-mode-linux/uml-patch-2.4.27-1.bz2 (I know this isn't the latest but works for me!!) With the networking I use the daemon option. I am using this for kernel development. I have also been working on migrating my code to a 2.6.x kernel on 2.4.27 host as well and there are a few things you need to know there if you go down that path on Debian Woody potentially. Feel free to ask more questions or correspond off list. Ian |
From: Blaisorblade <bla...@ya...> - 2005-04-12 17:47:32
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On Monday 11 April 2005 11:04, Simon Waters wrote: > On Friday 08 Apr 2005 6:28 pm, Blaisorblade wrote: > > On Friday 08 April 2005 17:04, Jelle Boomstra wrote: > > > On Friday 08 April 2005 16:49, Simon Waters wrote: > > > > Was running Debian testing on host, with the various Debian UML > > > > packages loaded from the other versions, and the Debian stable file > > > > system from the usermodelinux.org site. > > > > About SKAS: it's not mandatory, however since almost everybody uses SKAS > > mode, TT mode is frequently non-debugged. It's not abandoned, when > > mode-specific bugs are reported they usually get fixed soon. > > Well looks like there is a bug, but not sure how to report it other than > the kernel versions as before. > > > > Did you try a 2.6 kernel? you only mention 2.4 kernels, most > > > development is on 2.6 I guess. > > > > What is more important, is that 2.6 kernels are usually more stable *at > > all*. > > > > We aren't yet rewriting from scratch big parts of code, we are instead > > gradually and gradually fixing it more and more. There are some bigger > > changes, which are well tested anyway. > > > > Especially, try either 2.6.11-bs3, 2.6.11-bs1, or 2.6.9-bs7 (in this > > order). The last one is known to be a bit unstable in TT mode, however > > (where "a bit" means "install Gentoo to notice" or something like that). > > I tried a build of 2.6.11 (stock kernel) with the ARCH=um, Yes, that does not build on Woody, we have recently fixed that... try -bs4 from the website. > At this point I decided trying 2.6.11 was a step backwards from where I was > and found the "Debian Stable HOWTO" with the SKA patched 2.4.25 and found > that worked. > I can investigate the errors on the 2.6.11 kernel and rebuild with the > later patches - I was unclear as to whether I should need a host kernel > patch, and whether I could run 2.6 UMLs only on 2.6 host kermels, so > finding something that worked was a higher priority than finding out why it > didn't work. Of course now it works I have more time - if only waiting for > the upgrade from Woody to Sarge to run - now I've decided Woody really is > too old for what I want to do. > Thanks, > Simon -- Paolo Giarrusso, aka Blaisorblade Linux registered user n. 292729 http://www.user-mode-linux.org/~blaisorblade |
From: Simon W. <si...@zy...> - 2005-04-13 14:43:32
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On Tuesday 12 Apr 2005 6:54 pm, Blaisorblade wrote: > > > I tried a build of 2.6.11 (stock kernel) with the ARCH=um, > > Yes, that does not build on Woody, we have recently fixed that... try -bs4 > from the website. We have sarge as host, but I'll try -bs4 when I get some time. Busy making the UML do what it is suppose to, as I said all I needed was a stable UML, we aren't doing anything too complex, although if it succeeds no doubt I'll need more performance. Although it might be easier to buy more hardware ;) |