f20 lvm - inactive LV

[Chris Murphy]

On Mar 7, 2014, at 1:34 AM, Michal Kopacki <mkopacki at gmail.com> wrote:

>  hello,
> 
> This is my first post to that list so hello everyone.
> 
> After a few years break, I've decided to take Fedora on test drive (last Fedora I've seen was something around 11; I use centos/redhat on daily basis) and I must say there are many changes here (good and bad ones). Anyway, below my problem:
> 
> There is this thing with LVM which I can't understand - I did create few VGs and LVs and add them to fstab (as default) but after that strange things started to happen during system boot. It seems that not all LVs are activated during system boot (kind of randomness here). I came to this solution that I need to put all LVs I want to be mounted by default as kernel parameter (ie rd.lvm.lv=rootvg/rootlv). 

That's a dracut parameter, to cause the LV to become available early during boot. It's typically used for rootfs and swap.

> 
>  I can live with that when it comes to "system" LVs but problem is that I have many "non os" LVs on that machine and putting all of them as a kernel param doesn't seem right.

They should be activated automatically. On Fedora 20 I have no LVM so I disabled the first two units.

# systemctl list-unit-files | grep -i lvm
lvm2-lvmetad.service                        disabled
lvm2-monitor.service                        disabled
lvm2-pvscan at .service                        static  
lvm2-lvmetad.socket                         enabled 

I then created a new PV, VG, and LV, formatted it XFS. I didn't add it to fstab, nor did I enable any services above. Yet this LV is active on reboot.


# systemctl status lvm2-pvscan at 8:17.service
lvm2-pvscan at 8:17.service - LVM2 PV scan on device 8:17
   Loaded: loaded (/usr/lib/systemd/system/lvm2-pvscan at .service; static)
   Active: active (exited) since Sun 2014-03-09 20:16:58 MDT; 5min ago
     Docs: man:pvscan(8)
  Process: 322 ExecStart=/usr/sbin/pvscan --cache --activate ay %i (code=exited, status=0/SUCCESS)
 Main PID: 322 (code=exited, status=0/SUCCESS)

Mar 09 20:16:58 f20v.localdomain pvscan[322]: /dev/cdrom: open failed: No medium found
Mar 09 20:16:58 f20v.localdomain pvscan[322]: 1 logical volume(s) in volume group "VG" now active
Mar 09 20:16:58 f20v.localdomain systemd[1]: Started LVM2 PV scan on device 8:17.


# systemctl status lvm2-lvmetad.service
lvm2-lvmetad.service - LVM2 metadata daemon
   Loaded: loaded (/usr/lib/systemd/system/lvm2-lvmetad.service; disabled)
   Active: active (running) since Sun 2014-03-09 20:16:58 MDT; 5min ago
     Docs: man:lvmetad(8)
  Process: 328 ExecStart=/usr/sbin/lvmetad (code=exited, status=0/SUCCESS)
 Main PID: 330 (lvmetad)
   CGroup: /system.slice/lvm2-lvmetad.service
           └─330 /usr/sbin/lvmetad

Mar 09 20:16:58 f20v.localdomain systemd[1]: Started LVM2 metadata daemon.

I would start with:

journalctl -b -x -o short-monotonic --no-pager

And then start search for some of the above items, like pvscan, to see if it's scanning for PVs and if it finds anything, and if it activates anything, and if not why not. Status can also be helpful.


Chris Murphy