Acronis SnapAPI kernel module is not loaded (CL7 Hybrid kernel)

Issue

The problem can occur when the Acronis backup runs, this is happening after the conversion to Cloudlinux.   

modprobe snapapi26
modprobe: FATAL: Module snapapi26 not found in directory /lib/modules/4.18.0-425.19.2.lve.el7h.x86_64

Environment

• Acronis
• CL7 (Hybrid kernel)

Solution

1. First of all, check the DKMS version, for example:

# rpm -qa | grep dkms
dkms-3.0.3.3-99.noarch

• If the Hybrid kernel is in use, install the DKMS from CloudLinux as per article: https://kb.acronis.com/content/69434  
• If DKMS is already installed, consider downgrading it:

# yum downgrade dkms --enablerepo=cl7h_beta

• Try rebuilding the SnapAPI kernel module as per the instructions provided in the link: https://cloudlinux.zendesk.com/hc/en-us/articles/360019828720-The-SnapAPI-kernel-module-is-not-loaded-for-the-kernel 

2. In case the issue still persists and it shows something like this:

# dkms build -m snapapi26 -v 0.8.18 --config /boot/config-$(uname -r) --arch $(uname -p) --kernelsourcedir /usr/src/kernels/$(uname -r)

Preparing kernel 4.18.0-425.19.2.lve.el7h.x86_64 for module build:
(This is not compiling a kernel, just preparing kernel symbols)
Storing current .config to be restored when complete
Running Generic preparation routine
make mrproper...(bad exit status: 2)
using /boot/config-4.18.0-425.19.2.lve.el7h.x86_64
make oldconfig...
make prepare-all...(bad exit status: 2)

Running the pre_build script:
Generate "kernel_config.h" for kernel "4.18.0-425.19.2.lve.el7h.x86_64" and system map "/lib/modules/4.18.0-425.19.2.lve.el7h.x86_64//System.map".
Address of the function "printk" was defined
Function "blk_mq_submit_bio" not found
Function "_printk" not found

Building module:
cleaning build area...
make -j8 KERNELRELEASE=4.18.0-425.19.2.lve.el7h.x86_64 -C /usr/src/kernels/4.18.0-425.19.2.lve.el7h.x86_64 M=/var/lib/dkms/snapapi26/0.8.18/build...(bad exit status: 2)
Error! Bad return status for module build on kernel: 4.18.0-425.19.2.lve.el7h.x86_64 (x86_64)
Consult /var/lib/dkms/snapapi26/0.8.18/build/make.log for more information.

It`s necessary to install GCC8 + Devtoolset-7 and configure them.

2.1. Install cloudlinux-scl-release and devtoolset-7 packages.

# yum install cloudlinux-scl-release

# yum install devtoolset-7

2.2. Modify the framework.conf file in /etc/dkms/ to use GCC from devtoolset-7:

# nano /etc/dkms/framework.conf

## use GCC from devtoolset-7
PATH=/opt/rh/devtoolset-7/root/usr/bin:$PATH

# scl enable devtoolset-7 'bash -l'

3. Rebuild and Install the Module. Remove the existing SnapAPI26 module, load the appropriate tarball, build, and install the SnapAPI26 module:

# dkms remove snapapi26 -v 0.8.xx --all (insert correct version instead xx)

# dkms ldtarball /usr/lib/Acronis/kernel_modules/snapapi26-0.8.xx-all.tar.gz 

# dkms build -m snapapi26 -v 0.8.xx --config /boot/config-$(uname -r) --arch $(uname -p) --kernelsourcedir /usr/src/kernels/$(uname -r)

4. Load the module using `modprobe` and check its status using `lsmod` and `dkms` commands:

# dkms install -m snapapi26 -v 0.8.xx

# modprobe snapapi26

# lsmod | grep snapapi26

# dkms status snapapi26 |grep installed

5. Finally, restart the acronis_mms service:

# systemctl restart acronis_mms

6. Ensure that the backup works as expected.

Useful links

• https://cloudlinux.zendesk.com/hc/en-us/articles/360019828720-The-SnapAPI-kernel-module-is-not-loaded-for-the-kernel 
• https://kb.acronis.com/content/69434