What do you think about Fedora/FreeDesktop.org UsrMove Plan?

Yamakuzure · Posted: Tue Mar 20, 2012 4:07 pm Post subject:

I would like to know why everybody is going nuts about this "move". We have several servers (about 20 internal and external), all running with debian and they never had neither /usr nor /var on a different partition but the root partition. Backups were never an issue, everything that has to be backed up is on other drives. My two machines at work are running with gentoo on it with a non-extra /usr partition, and everything (udev-181 included) is working well.

People keep saying they have /usr in LVM, but why? Once everything is set up, /usr isn't growing this much any more. And if you really need something on a different partition (I have /usr/portage and /usr/lib/debug on other partitions) you can mount them or symlink them.

So, basically speaking, apart from the hassle to change the root partition size and to move /usr, what exactly is the problem?
_________________
Edited 220,176 times by Yamakuzure

dmpogo · Advocate Joined: 02 Sep 2004 Posts: 3468 Location: Canada

aidanjt · Posted: Tue Mar 20, 2012 4:21 pm Post subject:

Hypnos · Posted: Tue Mar 20, 2012 4:24 pm Post subject:

Hypnos · Posted: Tue Mar 20, 2012 4:31 pm Post subject:

baaann · Guru Joined: 23 Jan 2006 Posts: 558 Location: uk

aidanjt · Posted: Tue Mar 20, 2012 5:13 pm Post subject:

dmpogo · Advocate Joined: 02 Sep 2004 Posts: 3468 Location: Canada

sphakka · Tux's lil' helper Joined: 24 Jun 2003 Posts: 79

greyspoke · Apprentice Joined: 08 Jan 2010 Posts: 173

sphakka · Tux's lil' helper Joined: 24 Jun 2003 Posts: 79

greyspoke · Apprentice Joined: 08 Jan 2010 Posts: 173

sphakka · Tux's lil' helper Joined: 24 Jun 2003 Posts: 79

Thanks, greyspoke!

ExecutorElassus · Posted: Thu Mar 22, 2012 12:30 am Post subject:

So, it seems there are already ebuilds that depend on >=sys-fs/udev-182 (on my system, todays sync results in sys-auth/consolekit-0.4.5-r3[acl] needing it. I suspect more will come.

So, does that earlymount script you posted work? Like, should I try it out, or is this something best left to people who know what they're doing?

I guess my problem is, I'm still not sure what exactly I should do before unmasking udev. greyspoke, you give some init scripts; are those sufficient, or do I have to follow the wiki to build that initramfs as well?

And as far as the freedesktop people causing problems with this, didn't they say they're just complying with what is already the standard practice (that is, that scripts calling on things across the /usr boundary have been loading earlier in the boot process for some time, and just fail gracefully), and got tired of all the errors about it?

I'm fine with a script or whatever pre-mounting /usr to run udev rules. But I have zero experience with building an initramfs, and build my kernel manually (so, no genkernel, and I've never heard of dracut). What I would really love - since it seems we can do this with a couple system tools and a script - would simply be a clear documentation for how to build an initramfs that does what's necessary to keep udev from puking. It seems like what they'd prefer to have happen is to stop splitting system tools across the /usr boundary anyway, and it seems like the tradeoff (if I understand it correctly, which I probably don't) is to pre-mount /usr.

So, greyspoke's scripts look like fun. Anybody mind spelling out for idiots (me) how to implement them?

Thanks,

EE

greyspoke · Apprentice Joined: 08 Jan 2010 Posts: 173

FastTurtle · Posted: Thu Mar 22, 2012 3:43 pm Post subject:

As I was one of the many that build tested w/o udev/hotplug and a number of other so called features, I don't understand what the problem is with deprecating udev and its flag. Seriously those of us that actually tested the lack didn't have many issues - most were related to automounting and we quickly discovered that there were fewer headaches by not allowing things to automout - things like perms failing to update, can't umount something automounted except as root - or partial mounting and having to su to root and fix the problems from that.

Even on my work machine, the IT dept doesn't allow windows to automount/autorun anything anymore and it's been that way for the last 7-8 years in the good shops. So why should linux be any different. People are already used to manually mounting things except maybe music cd's and where I work, after the Sony Root Kit debacle, they don't even allow us to do that for safety reasons and you know what, we don't miss it.

What I suggest be done is for the devs and everyone to begin testing to see if they really need udev/hotplug and the features it supposedly brings with it as I suspect you'll be suprised just how little benefit it offers now.

For the devs, they should be able to list all packages that depend on udev so we can begin looking at whether it's an explict dependency or a use-flag issue. Sure it's going to take some effort but isn't Q/A testing why catalyst and the autobuild systems are there? I know, who wants to babysit something like this where there's more exciting things going on but the benefits should outweight the effort if we can freeze and deprecate udev before completely removing it.

IMO udev simply adds another layer of complexity that doesn't offer any real benefit, thus it should be removed as quickly as possible for stability reasons. For those who think the system can't mount your raid/lvm setups, then you haven't configured your fstab correctly. That's exactly what it is for. It's the same for every filesystem on a Linux box. If fstab isn't setup right, things break and it's a PEBKAC (user error). Do it right folks. That means the simplest method possible, not as MS likes, the most complex, convuluted, misbegotten excersie in frustration we've all seen. In other words, if you're working for the computer, then you're doing it wrong as the computer is supposed to work for you. So why isn't it?

Those using disk encryption shouldn't have anymore problem setting up their fstab then those using raid. If they do then there's something wrong with the encryption method as it shouldn't add anymore complexity then the PW being needed during boot/mounting of the drive/partitions. Yes I'm a lazy person but it's a smart lazy as I prefer the system to work for me, not me for it. This means that once it's configured, I shouldn't have to do anything more to it unless it breaks or something fails. Until then I follow the "If it aint broke - don't fix it" principle and it works quite well for this lazy penguin.

ExecutorElassus · Posted: Thu Mar 22, 2012 5:42 pm Post subject:

Turtle: I like your approach even better.

Okay, so what's the process to wean myself from udev? Again, I'm kinda stupid with this stuff, so I depend on documentation. On my system, I have a couple packages that seem to depend explicitly on udev:

chromium
udisks
devmanager
lvm2

and a couple others.

Cheers,

EE

sphakka · Tux's lil' helper Joined: 24 Jun 2003 Posts: 79

So I tried greyspoke's method. I had to make some adjustments which I'd like to discuss -- that might actually depend on the fact that I use OpenRC (~)0.9.9.3:

1) the regex to catch relevant lines in fstab is IMHO more robust and (possibly) POSIX-ish like this:

comprookie2000 · Posted: Thu Mar 22, 2012 6:45 pm Post subject:

Its a work in progress;
https://bugs.gentoo.org/show_bug.cgi?id=407959
_________________
http://dev.gentoo.org/~dabbott/

steveL · Posted: Thu Mar 22, 2012 7:24 pm Post subject:

You can do the extraction with one awk command:

greyspoke · Apprentice Joined: 08 Jan 2010 Posts: 173

Thanks for the feedback sphakka and steveL. A difference between hacking for one's own use and writing stuff that works more generally, I wouldn't pretend to be a proper programmer but I will look into being POSIX compatible.

sphakka - if things are mounted ro initially, how do you get them unmounted, checked and remounted later? If I just change the script to mount ro, fsck complains and won't do a check, and after that the world and its wife whinge about not being able to write to various files. I have noticed messages about lvm (on shutdown) as well, I think they are just informational.

steveL - your method appears more relevant, thanks for pointing it out. As I see it, having udev start early and decide what services to run based on the hardware it finds is useful for achieving a "no configuration required" system. But if your basic system hardware doesn't change much and you don't mind configuring it manually, all you want udev for is hotplugging/ naming of peripheral things once the basic box has started up. So starting it late (rather than mounting things early) makes more sense.

Having said all this, if I was building my system now, I would bung everything on one partition and be done with it.

sphakka · Tux's lil' helper Joined: 24 Jun 2003 Posts: 79

steveL · Posted: Sat Mar 24, 2012 6:52 pm Post subject:

greyspoke · Apprentice Joined: 08 Jan 2010 Posts: 173

I will start a thread in "kernel and hardware" when I get the chance then.

aCOSwt · Posted: Fri Mar 30, 2012 11:05 am Post subject:

Initramfs-less, is this all-in-one filesystem charming tendency ? fashion ? whim ? policy ? (pardon-me, english is not my native language)...
likely to concern /tmp ; /var/tmp ; /var/log too in a more or less near future ?
_________________