sys-fs/lvm2-2.02.108 fails on static libs

ExecutorElassus

This seems to be a common issue with lvm2, but it's only recently popped up for me. I get the following:

Hu · Moderator Joined: 06 Mar 2007 Posts: 21602

As I understand it, udev upstream so thoroughly broke support for separate /usr that you likely already use an initrd to mount /usr (or are affected by other problems related to udev assuming /usr is available early). If you use a initrd, and that initrd mounts /usr, then you do not need USE=-static on lvm2 if you also place the necessary C library shared objects in the initrd. Are you using static lvm2 because you did not place glibc shared objects in the initrd?

ExecutorElassus · Posted: Sun Aug 17, 2014 4:20 pm Post subject:

I followed the instructions in this guide, which instruct to build lvm with static. However, this appears to be for the purpose of building a busybox shell to check /usr and /var before mounting, and does not indicate whether that flag is needed after the initramfs/initrd has been built.

Is that not the case? ie, now that I've built an initramfs using this guide, can I then drop the static flags from those packages? Also, how often should I update that initramfs? Neddy suggested it should be quite rare, but I haven#t updated it since the guide came out (and that was over two years ago at this point).

Cheers,

EE

saellaven · l33t Joined: 23 Jul 2006 Posts: 646

Check out this thread if you're interested in a separate /usr and don't want the headaches or potential breakages that come with an initramfs/initrd (it's possible for certain packages to get updated which will break your system if your initramfs isn't rebuilt also, which has already happened in the past for some people. If you don't regularly rebuild your initramfs, eventually, your luck IS going to run out even if things have been fine so far).

I've been using it for quite a while and it is stable, but WilliamH refuses to accept the patches for all I can assume are petty, personal reasons.

I'm using it with sys-fs/lvm2-2.02.103 and sys-fs/eudev-1.9-r2 (I don't trust udev and don't want systemd anywhere near my systems) without problem.

Hu · Moderator Joined: 06 Mar 2007 Posts: 21602

You need USE=static if you want to run the resulting binary without having a copy of the glibc shared objects available. I prefer to take the size hit of building an initrd that has glibc shared objects included, so that I can then place nearly arbitrary non-static commands in my initrd without special handling. If you do this, then you do not need static lvm. If you rebuild the initramfs to try this, save your old one aside until you know the new one works. It is easy to make a mistake with this conversion and the result will be an initrd that fails to mount any LVM-managed volumes. Depending on your filesystem locations, that could be an inconvenience or it could be a showstopper.

blu3bird · Posted: Sun Aug 17, 2014 10:23 pm Post subject:

sys-apps/util-linux and sys-fs/udev both include the function mkdir_p. If two different libraries include the same functions, gcc(ld) errors just like this.

As a workaround you can compile lvm with LDFLAGS="-Wl,-zmuldefs" which will give you a working lvm but please open a bug for this.
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gagern · n00b Joined: 26 Nov 2003 Posts: 54

I encountered the same, and filed bug 520450 for this.

ExecutorElassus · Posted: Fri Aug 22, 2014 8:07 am Post subject:

thanks for filing. I got distracted and neglected to do this

Cheers,

EE

ExecutorElassus · Posted: Wed Aug 27, 2014 7:47 pm Post subject:

so it seems now that lvm2 has the following USE:

saellaven · l33t Joined: 23 Jul 2006 Posts: 646

ExecutorElassus · Posted: Wed Aug 27, 2014 9:02 pm Post subject:

I saw that, and it's complicated

I have a bunch of questions about it. My partitions are identified by UUID in fstab; will this make a difference? FWIW, I get error messages about not finding /dev/vg volumes during boot.

I'm interested in that HOWTO, but haven't had the head for it since you first posted. How do you patch the files in question? To I add the patch files to a local patch repository to patch them into the ebuilds? How do I keep things like /etc/init.d/udev from reverting to their unpatched state after every update?

Your Howto needs a Howto

EE

saellaven · l33t Joined: 23 Jul 2006 Posts: 646

ExecutorElassus · Posted: Thu Aug 28, 2014 10:32 am Post subject:

actually, the UUIDs were only there to get the initramfs to work; I'm fine with listing partitions by /dev/mapper nodes instead.

Sigh. I'll set to work on this over the weekend. I'm not in any shape to do real work on the system during the week. It's not frustration with the instructions per se. I'm just not much for up during the week besides tea and cake and binge-watching whatever

Thanks for your advice on this. On the side, how different is eudev? Is it in a mature state? Does it work better? Is there a guide somewhere? If I'm going to be reconfiguring the system, I might as well look into that as well.

Cheers,

EE

saellaven · l33t Joined: 23 Jul 2006 Posts: 646

ExecutorElassus · Posted: Thu Aug 28, 2014 3:57 pm Post subject:

trying that resulted in emerge attempting to downgrade util-linux to 2.24.x (I'm at 2.25), which failed on the following:

saellaven · l33t Joined: 23 Jul 2006 Posts: 646

ExecutorElassus · Posted: Fri Aug 29, 2014 9:57 am Post subject:

actually, that USE requirement was added afaik to all lvm2 ebuilds due to changes in udev (see the bug report above). You may find that even stable packages now disallow static lvm with udev.

Anyway, more news in a couple days.

ExecutorElassus · Posted: Sun Sep 14, 2014 12:08 pm Post subject:

It seems there's a slight wrinkle in the initramfs-free setup you linked: I also have / on a partition managed by lvm (so far as I can tell; it's on RAID1, listed as /dev/md126 by 'mount'). According to your guide, that doesn't work, correct?

Am I incorrect? Or do I need to re-compile lvm2 with -static? If the latter, will the initramfs I have still work?

Thanks,

EE

NeddySeagoon · Posted: Sun Sep 14, 2014 1:46 pm Post subject:

ExecutorElassus,

With root on a LVM volume you need an initrd containing lvm, since you need to start lvm from userspace before you can mount root to get at userspace.

It doesn't matter if lvm is built with USE=static or not as long as all the bits are in the initrd, it will still work.
Until recently, USE=static was preferred, but run lddtree on the binary will tell you the libs it needs. Add these to the initrd and you are good.
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NeddySeagoon

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those that do backups
those that have never had a hard drive fail.

ExecutorElassus · Posted: Sun Sep 14, 2014 1:49 pm Post subject:

Neddy! So good to hear from you! I always feel better seeing you in a thread, you're legit.

Cheers, mate. I'll just drop the static flag from lvm and proceed.

Thanks.

EE