https://access.redhat.com/solutions/5347091

System fails to mount filesystem on multipath partition during boot time in RHEL8
Solution Verified - Updated May 31 2021 at 2:25 PM - English
Environment

Red Hat Enterprise Linux 8
    dracut-049-27.git20190906.el8.x86_64

Issue

System fails to mount filesystem created on multipath partition during boot time in RHEL8.

Raw

[ 235.191955] testsystem systemd[1]: Mounting /sysroot...
[ 235.398136] testsystem kernel: SGI XFS with ACLs, security attributes, no debug enabled
[ 235.398913] testsystem mount[2922]: mount: /sysroot: /dev/sdb4 already mounted or mount point busy.
[ 235.399207] testsystem systemd[1]: sysroot.mount: Mount process exited, code=exited status=32
[ 235.399259] testsystem systemd[1]: sysroot.mount: Failed with result 'exit-code'.
[ 235.399480] testsystem systemd[1]: Failed to mount /sysroot.

Resolution

Upgrade dracut package to dracut-049-135.git20210121.el8 as per RHBA-2021:1661
As a workaround, rebuild initramfs with /lib/udev/rules.d/11-dm-parts.rules.

Raw

dracut -f -v --include /lib/udev/rules.d/11-dm-parts.rules /lib/udev/rules.d/11-dm-parts.rules

Or create /etc/dracut.conf.d/part.conf with below lines and rebuild initramfs image.
#vi /etc/dracut.conf.d/part.conf
install_items+=/lib/udev/rules.d/11-dm-parts.rules

Root Cause

dracut doesn't install /lib/udev/rules.d/11-dm-parts.rules, which is what changes the link priority for kpartx partition devices, which should make /dev/disk/by-uuid point to multipath devices instead of the scsi path devices.

Diagnostic Steps

Check boot logs and verify whether root filesystem mounted using sdX device or mpath device.

Raw

[ 235.185721] testsystem systemd[1]: Starting File System Check on /dev/disk/by-uuid/3a9fc23b-e95d-44a2-b95c-9651799f8c77...
[ 235.190597] testsystem systemd-fsck[2920]: fsck.none doesn't exist, not checking file system on /dev/disk/by-uuid/3a9fc23b-e95d-44a2-b95c-9651799f8c77.
[ 235.191192] testsystem systemd[1]: Started File System Check on /dev/disk/by-uuid/3a9fc23b-e95d-44a2-b95c-9651799f8c77.
[ 235.191955] testsystem systemd[1]: Mounting /sysroot...
[ 235.398913] testsystem mount[2922]: mount: /sysroot: /dev/sdb4 already mounted or mount point busy.

Verify /lib/udev/rules.d/11-dm-parts.rules rule available in initramfs image.

Raw

lsinitrd initramfs-4.18.0-193.el8.x86_64.img |grep dm-parts |wc -l

0

Rebuild initramfs image with /usr/lib/udev/rules.d/11-dm-parts.rules.

Raw

#lsinitrd initramfs-4.18.0-193.el8.x86_64.img |grep dm-parts
Arguments: -f -v -a 'multipath' --include '/usr/lib/udev/rules.d/11-dm-parts.rules' '/usr/lib/udev/rules.d/11-dm-parts.rules'
-rw-r--r-- 1 root root 1442 Dec 17 2019 usr/lib/udev/rules.d/11-dm-parts.rules

@danp

thanks for replying!

Red Hat Virtualization (RHVH) installation not booting on XCP-NG

If I create it on XCP-NG, it always failed while booting
I tried BIOS, UEFI, other install media, rhel8 template,

the boot process shows:
Failed to mount /sysroot
hostname also does not apply correctly

it says:

mount: /sysroot: cannot mount /dev/mapper/rhvh-root read only.
kernel: XFS (dm-3): log mount failed
systemd[1]: sysroot.mount: Mount process exited, code=existed status=32
systemd[1]: sysroot.mount: Failed with result 'exit-code'.
systemd[1]: Failed to mount /sysroot.

• I tried this on VirtualBox, it just boot to the OS normally, so I presume may be it has something to do with the hypervisor,
• including hostname applied correctly,
• and also, in virtualbox, the boot menu shows RHVH -4.4.9.2 and so on
• while with XCP-NG VM, the boot menu shows Red Hat Enterprise Linux (kernel version)
• virtualbox use sda while XCP use xvda (so may be because of this?)

Thanks!

@olivierlambert
What to do with RAM, how we can oversubscribe it?

Thanks!

last time I did power up a lot of VMs, if I remember it, Xen didnt allow it because I ran out of vCPU,

Am I wrong maybe?

So no need to do anything right, just turn it on, it will work?

Hi @olivierlambert

Could you point out the doc/reference/info about it?
Especially CPU,

Thanks!

Is XCP-NG support CPU and memory RAM over commit?

Hii,

yes its working,
but not the second 2.5 Gb ethernet, since it requires newer kernel,
same with PCI passthrough the wifi card is new popular AX200 which requires newer kernel also,

I have USB passthrough a Wifi USB adapter, the speed looks underperforming, but i haven't test the adapter plugged in to laptop and see its speed comparison,
I didnt ask much about it, since I guess its not coorporate use case except closely to edge computing? maybe not too important?

if you need other info, you can tell me, perhaps some logs or debuging, i will share

its working, it just took very long time to detect,