[linux-lvm] how to deactivate vg hosting root filesystem

[linux-lvm] how to deactivate vg hosting root filesystem

[Joe Harvell]

So I set up an initrd that starts raid and lvm before doing a pivot_root
and execing init.  This has been working fine for a long time.

The only problem I have is that the only way I know of to free up the vg
for deactivation is to make init exit, which panics the kernel.  How do
I do this safely?

Re: [linux-lvm] how to deactivate vg hosting root filesystem

[Luca Berra]

On Tue, Jul 17, 2001 at 09:11:26PM -0500, Joe Harvell wrote:
> So I set up an initrd that starts raid and lvm before doing a pivot_root
> and execing init.  This has been working fine for a long time.
> 
> The only problem I have is that the only way I know of to free up the vg
> for deactivation is to make init exit, which panics the kernel.  How do
> I do this safely?
At the moment there is no need to deactivate the root VG.

L.

-- 
Luca Berra -- bluca@comedia.it
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[linux-lvm] success report 2.4.10 + 1.0.1-rc2 + diff

[Jim Cromie]

fwiw,

Im pleased to report success using linux-2.4.10, LVM-1.0.1-rc2,
and this patch: http://incandescent.mp3revolution.net/lvm/inline_fix.diff
on a basically stock RH-7.1 installation.

I made 1 minor patch to /etc/rc.d/rc.sysinit, probably theres a better
way..

+ # LVM initialization
+ action "loading LVM:" /sbin/insmod lvm-mod
if [ -e /proc/lvm -a -x /sbin/vgchange -a -f /etc/lvmtab ]; then
        action $"Setting up LVM:" /sbin/vgscan && /sbin/vgchange -a y
fi

and possibly a couple manual edits to lvm-*.c;
min(z,x,y) -> min(x,y), max() too

so now, bootup works, and shows results as follows

[jimc@groucho jimc]$ df
Filesystem           1k-blocks      Used Available Use% Mounted on
...
/dev/hdc5              4031656   3762168     64692  99% /home
/dev/_vgb/vl_tmp        495844        24    470220   1% /tmp
/dev/_vgb/vl_t2        1511856    326156   1108900  23% /mnt/new

[root@groucho /root]# vgdisplay
--- Volume group ---
VG Name               _vgb
VG Access             read/write
VG Status             available/resizable
VG #                  0
MAX LV                255
Cur LV                2
Open LV               2
MAX LV Size           255.99 GB
Max PV                255
Cur PV                1
Act PV                1
VG Size               9.36 GB
PE Size               4.00 MB
Total PE              2397
Alloc PE / Size       500 / 1.95 GB
Free  PE / Size       1897 / 7.41 GB
VG UUID               6w4vI8-x2Qp-rqFg-soa6-eYOF-2Uwp-8sB7z8

[root@groucho /root]# lvdisplay /dev/_vgb/vl_t*
--- Logical volume ---
LV Name                /dev/_vgb/vl_t2
VG Name                _vgb
LV Write Access        read/write
LV Status              available
LV #                   1
# open                 1
LV Size                1.46 GB
Current LE             375
Allocated LE           375
Allocation             next free
Read ahead sectors     120
Block device           58:0

--- Logical volume ---
LV Name                /dev/_vgb/vl_tmp
VG Name                _vgb
LV Write Access        read/write
LV Status              available
LV #                   2
# open                 1
LV Size                500.00 MB
Current LE             125
Allocated LE           125
Allocation             next free
Read ahead sectors     120
Block device           58:1



the only hitch I had configing was using lvrename, vgrename;
IIRC. I had to mv the /dev/_vgb special files myself,
causing a couple of fstab-umount-reboot-to-single
sessions to clean up errs.  I used the 2nd cmd-form,
"vgrename vg02 my_volume_group", if that matters.


Perhaps a FAQ entry explaining what I may have mis-understood:

{lv,vg} rename dont change names of /dev/ special-files,
nor corresponding entries in /etc/fstab.  You must manually edit your mount
points.


looking forward, I plan to fix the problem with 99% on /home

thanks for great software.