On 12/02/2015 12:05 PM, Axel Glienke wrote:> in journalctl i found: > modprobe: FATAL: Module dm-snapshot not found > ... > Can't process LV root_snap: snapshot target support missing from kernelI installed a very simple CentOS 7 system with an LVM root FS. Created a snapshot and rebooted, no problem. Updated dracut, then updated everything else and rebooted, no problem. As far as I can tell, dracut normally includes the entire kernel module tree under kernel/drivers/md, which should provide the dm-snapshot module required to complete the boot sequence. I can't determine what's causing the problem you see, but it doesn't appear to affect a standard installation. Try: dracut --force --debug > /var/tmp/dracut.txt 2>&1 Upload /var/tmp/dracut.txt to http://paste.fedoraproject.org/. I'll see if I spot anything useful.
ok, thank you very much Gordon. but you know what the difference? if i do 1. centos7 installation 2. yum upgrade 3. lvcreate -s ... 4. reboot then i got the error. if i do your way 1. centos7 installtion 2. snapshot & reboot 3. yum upgrade 4. reboot then the system start. Zitat von Gordon Messmer <gordon.messmer at gmail.com>:> On 12/02/2015 12:05 PM, Axel Glienke wrote: >> in journalctl i found: >> modprobe: FATAL: Module dm-snapshot not found >> ... >> Can't process LV root_snap: snapshot target support missing from kernel > > I installed a very simple CentOS 7 system with an LVM root FS. > Created a snapshot and rebooted, no problem. Updated dracut, then > updated everything else and rebooted, no problem. > > As far as I can tell, dracut normally includes the entire kernel > module tree under kernel/drivers/md, which should provide the > dm-snapshot module required to complete the boot sequence. > > I can't determine what's causing the problem you see, but it doesn't > appear to affect a standard installation. > > Try: > > dracut --force --debug > /var/tmp/dracut.txt 2>&1 > > Upload /var/tmp/dracut.txt to http://paste.fedoraproject.org/. I'll > see if I spot anything useful. > _______________________________________________ > CentOS mailing list > CentOS at centos.org > https://lists.centos.org/mailman/listinfo/centosGr??e Axel
On 12/02/2015 02:02 PM, Axel Glienke wrote:> ok, thank you very much Gordon. > > but you know what the difference? > > if i do > 1. centos7 installation > 2. yum upgrade > 3. lvcreate -s ... > 4. reboot > > then i got the error.I'll try to recreate the problem on a new VM, but that doesn't make much sense. Including the required module isn't dependent on creating the snapshot as far as I can tell. If you can get dracut debug output from an affected system, I might be able to help. Without that, I can't think of anything else I can offer you. dracut --force --debug > /var/tmp/dracut.txt 2>&1 (Upload /var/tmp/dracut.txt to http://paste.fedoraproject.org/)