On Thu, Jan 15, 2009 at 10:42 AM, Rob OpenSuSE <rob.opensuse.linux@googlemail.com> wrote:
Abuse and patronise me all you like, but some time spent studying VM issues, might help your low RAM system.
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Increasing the swappiness factor, as per Andrew Morton's view point, will save you some memory. Not huge amounts, but it'll be more signicant than whether the kernel loaded device mapper or not.
1) device-mapper was an example - a VERY simple example - of something which is loaded which has NO explicity dependency set in any other loaded service, module or toolkit running on the system after an Automatic Configuration. It only exists on the POSSIBILITY that someone wants LVM2 at some point. This is inefficient by design, it is as simple as that. That it saves 80KiB in loading the module - fringe benefit. I am sure it allocates some more, hooks itself into several subsystems, and then just hangs around being redundant. We simply do not do this where I come from. If it's not used, and it is not a dependency of any required component in the system, it don't get run. 2) swappiness is STILL not desired on our system because I keep saying that the disk is so goddamned slow that it actually severely impacts the responsiveness of the system. It is NOT a solution. How.. many.. times.. do... I .... need.. to... point.. .this.. out? 3) you are not running an Efika, nor a PowerPC, so your "I don't see it on my 256MB x86 system so I don't believe your claims"-style statements are invalid anyway. Even with 256MB and a much faster system (personally I have a Via EPIA, Pegasos 1GHz G4, MPC8641D dual core 1.5GHz, a 2.4GHz Pentium 4 and a bunch of VirtualBox installations), resource usage after boot on SUSE 11.1 compared to 10.3 is far, far higher - by something like 70MB just booting GNOME. It is much easier to give you the example of device-mapper because it is a service that, without LVM2, is absolutely totally redundant, and only *needs* to be started as an explicit dependency of LVM2 support modules (boot.lvm or boot.dmraid) and/or tools. Cups and HPLIP only *need* to be started as explicit dependencies on *actually having a printer* (it does not affect udev hotplug of USB printers that cups is not running!). rpcbind only *NEEDS* to be started if a service using rpcbind/portmap is started too. The FUSE kernel module only *needs* to be started when you start using fusemount. Postfix is only there as a dependency of cron (since cron needs to send mail) and it is bloated for the purpose, there are much better solutions in use on other distributions (Debian/Ubuntu use ssmtp). These are very very simple dependency issues which are not solved at some fundamental problem in the system of designing init scripts and their order and status. I do not install systems with LVM2 yet every system has boot.device-mapper active. This is the simplest to explain scenario. *WHY* is this the case? And Rob, I don't even want an answer from you, I want someone who actually knows what they are doing, actually handles this subsystem in SUSE, and is paying attention. -- Matt Sealey <matt@genesi-usa.com> Genesi, Manager, Developer Relations -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org