Linux performance

krautmick

Over the years, I have struggled with Linux on many occassions. And when I say many, I mean many. Before you dismiss me as yet another Windumb user, let me state that I used Linux when the Kernel revision read something like 1.2.x and I was recompiling the kernel to get ISDN drivers to work, so do give me just a little credit to start

The main reason I guess I always ended up falling back to plain old windows has been twofold: Games and the fact that I didn't really have a reason I needed to use Linux.

That has changed. For one I game less in my "old years" and what I do play, may well run under WINE and secondly I need networking tools that are only available or perform better under Linux. So here I go again, probably for the 10th time.

Over the last days, I have been installing various distributions on PCs and VMs, from Debian to Ubuntu 11.04 and Backtrack 5. Each and all of them with their own issues, which is neighter uncommon or surprising. I know that's normal.

What did strike me though, is the fact that nearly every HD install I have done is crawling slow in comparison to e.g. Win7 startup. E.g. one of the main reasons I'd love to put Linux on my laptop was that I wanted a system that could boot into OS quickly and give me Wireless Internet within a few seconds. Yet I find myself reverting back to the Win7 partition and cursing the grub loaders delays now.

So here is my questions then:

1) For some odd reason, I now have a delay of as much as 30sec before the Grub menu even appears and a delay of 1-2sec before it responds to a keypress. Something not right there.

2) Loading from grub is very slow. I did use ext4 and when I googled the issue, there is some references to grub being slow with ReiserFS, but that ext4 is fully supported in 11.04 etc. Is there any known issues with grub that would speed it up?

3) I have it somewhere in the back of my head, that people claim Grub is way better than LILO. Personally I always liked LILO, but I (probably stupidly) followed the common consensus and use Grub. Is there actually merit in this, given that LILO is still knocking around?

4) Distributions. I picked Ubuntu and Debian for 2 reasons. Ubuntu is the underlying distro for BT5 and it seems to be rather popular atm, so I though I grab that to get familiar with it. I also chose Debian, as I heard that it runs well on old hardware and I plan to revive some old desktops and turn them into network sniffers.
Is there something else I should consider?

5) Booting. It used to be the case, that one had to recompile the kernel to get a faster boot, by throwing out unnecessary drivers etc. I read posts that claim that recompiled kernels will really only save on HD space and could of course may cause compatibility issues. What's the most efficient way to streamline the bootstrap now?

In closing I say one thing though. The various package managers are a blessing. I dread to think back at manually creating the various locations for libs and changing config files just to get some tool working. Seem like most distros have their own versions of that now.

Naikon

Your argument about boot time is valid. Unix systems have traditionally been a bit slow to boot. Takes nearly a min for OpenBSD to boot on my machine. Linux is a bit nippier. X86 being optimised mostly for Windows might play a part here. Upstart annoys me to the core though. Buggy even for a desktop. BSD rc initialisation is more sane than SysV. Upstart is a mess.

Compiling the kernel was fun in the past for me, but i've moved onto actually working on the system now. I don't enjoy Gentoo not because I don't understand how to use it but because it is just too time consuming. Sitting for a week watching packages compiling is not a productive use of time when you consider the optimisation benefits from compiling with -O3 and other questionable compiler flags will probably reduce the stability by a huge margin.

Eliot Rosewater

I'm surprised about your experiences with boot up time. Every time I install Ubuntu on a computer it boots up faster than the Windows OS on it - and that includes a brand new version of Windows 7 that's installed alongside Ubuntu on my girlfriends laptop.

Naikon

Eliot Rosewater wrote: »

I'm surprised about your experiences with boot up time. Every time I install Ubuntu on a computer it boots up faster than the Windows OS on it - and that includes a brand new version of Windows 7 that's installed alongside Ubuntu on my girlfriends laptop.

Upstart is mostly to thank for this. For an system admin though, Upstart is nowhere near as mature. Ever used a RedHat/CentOS box? Takes ages to boot the system due to the use of old SysV init code. Old code tends to be reliable if maintained though. Don't get me wrong, Upstart does decrease boot times, but I would never use it on a server, at least for the time being. I would argue the rc startup solution is the most elegant. No reams of spaghetti symlinks to babysit, just add it to /etc/rc.conf.local by hand and move on.

PrzemoF

krautmick wrote: »

1) For some odd reason, I now have a delay of as much as 30sec before the Grub menu even appears and a delay of 1-2sec before it responds to a keypress. Something not right there.

Some blind shots: hard drive autodetect in BIOS? A non-existing floppy that BIOS is looking for? Try to tweak some settings - turn off POST, disable/remove CD. Let us know if it made any difference.

krautmick

Thanks guys.

No, the referred system is a modern one, I didn't get cracking with the old HW yet. So no floppies, SATA2 drives etc.

Its not the BIOS bootstrap, its something with Grub specifically. I'm going to try out LILO first and see what the difference is.

On another note: BT5 installed within a VM on HDD boots within a few seconds. Definitely not an issue with the processor.