Bug 40394 – LVM does not work on 20040128 LiveCD

• Status: RESOLVED WORKSFORME
• Product: Gentoo Release Media

[Description Alan Hughes 2004-02-04 11:32:11 UTC]

LVM does not work correctly on the 20040128 LiveCD. vgscan correctly detects the VG's (although it complains about a read-only file system), however vgchange -a y fails since it is unable to find the DeviceMapper entries in /dev.

Reproducible: Always
Steps to Reproduce:
1. Boot LiveCD
2. vgscan
3. vgchange -a y
Actual Results:  
vgscan OK 
vgchange fails when it cannot find DM entries in /dev 

Expected Results:  
vgchange should activate the VG and add entries in /dev

[Comment 1 Benjamin Judas (RETIRED) 2004-02-04 12:05:41 UTC]

What kernel did you boot? experimental or gentoo ?

[Comment 2 Alan Hughes 2004-02-05 00:03:53 UTC]

Problem existed with both kernels!

[Comment 3 Alan Hughes 2004-02-05 12:18:09 UTC]

Problem is still in the 2004-02-04 LiveCDs. At the moment it is impossible for me to test Gentoo since LVM is integral to the way I manage my disks.

[Comment 4 gent_bz 2004-03-04 08:04:07 UTC]

Have you tried 'insmod lvm-mod && insmod dm-mod' ?

(along with possibly a 'vgmknodes')

Seems to work for me...

[Comment 5 Gentoo LiveCD Package Maintainers 2004-03-04 08:25:29 UTC]

*** Bug 43704 has been marked as a duplicate of this bug. ***

[Comment 6 John Davis (zhen) (RETIRED) 2004-03-04 23:00:10 UTC]

have you tried the 2004.0 livecd?

[Comment 7 John Davis (zhen) (RETIRED) 2004-03-04 23:02:27 UTC]

*** Bug 43578 has been marked as a duplicate of this bug. ***

[Comment 8 Seemant Kulleen (RETIRED) 2004-03-05 13:15:34 UTC]

alan, well?

[Comment 9 Alan Hughes 2004-03-06 03:32:13 UTC]

I have'nt managed to try the 2004.0 LiveCD yet (first attempt resulted in a coaster). Am re-downloading the ISO image even as I speak, will burn it and try again later today and report the results.

[Comment 10 Frank Gore 2004-03-06 08:00:14 UTC]

Using the 2004.0 LiveCD, I ran vgchange -a y before running vgmknodes, and all the logical volumes were finally loaded into the /dev tree.

However, while going through the Gentoo installation, I forgot to add lvm to my use flags, so LVM was never installed. When I rebooted, the kernel couldn't load any of the LVM volumes and failed. Resolving this will take yet more time I'm not willing to devote to Gentoo, so I gave up again.

And this is really where the bug lies. LVM may be supported by Gentoo, but very poorly, and with no effort to inform the user how to do so. The LVM modules should be automatically loaded by the LiveCD, users should not have to go fetch for them. Any existing LVM volume group(s) and logical volume(s) should be automatically detected by the LiveCD during boot and made available to the user. And the installation instructions should mention that LVM support needs to be specified while setting up the base system. But none of this is done! All we get is some obscure statement that LVM is supported by Gentoo, nothing else.

[Comment 11 Alan Hughes 2004-03-06 08:40:44 UTC]

LVM volume group correctly handled by 2004.0 Universal LiveCD. Bug report can be closed now.

Note that there was no need to run vgmknodes.

[Comment 12 Benjamin Judas (RETIRED) 2004-03-06 09:22:41 UTC]

Frank, you may be right. In fact, LVM isn't covered in the installation manual. We think that a user want's to use LVM should have the basics to create such volumes. Describing the strategies with multi-device-volumes surely is too much for an installation manual.

Alan, thanks for testing. I'll set this Bug to WORKSFORME. That way we're able to collectively keep it in mind.

[Comment 13 Meder Bakirov 2004-03-09 03:20:35 UTC]

OK, I used "modprobe dm-mod" and it worked :)