Skip to content

Converting CentOS 7 to VZ7 for installing SolusVM on it

According to the official Virtuozzo 7 information, the proper and reliable way to use OpenVZ 7 virtualization is to deploy the server using Virtuozzo 7 ISO image from

If due to whatever reason there is no way to deploy the server using ISO, there is also a way to convert CentOS 7 to VZ7. Such scenario is not fully supported by SolusVM and should be performed on the server's owner risk

Preparing partitioning on CentOS 7 node for conversion

Before proceeding with installing vzkernel, it is required to prepare the server to match the requirements of Virtuozzo 7. The main part here is to have a dedicated EXT4 partition mounted on /vz.

Mount a specifically created partition or a logical volume (it's a preferable way, it will be easier to extend it if required). The file system on the partition/volume must be ext4. Do not forget to add the corresponding mount point to /etc/fstab.

Here are the sample steps on how to achieve that in case there is a second drive /dev/sdb. Note that steps are just an example.

sda 8:0 0 64G 0 disk
├─sda1 8:1 0 1G 0 part /boot
└─sda2 8:2 0 21G 0 part
├─centos-root 253:0 0 20G 0 lvm /
└─centos-swap 253:1 0 1G 0 lvm [SWAP]
sdb 8:16 0 64G 0 disk
vgcreate vz /dev/sdb
Physical volume "/dev/sdb" successfully created.
Volume group "vz" successfully created
lvcreate -n vz -l 100%FREE /dev/vz
Logical volume "vz" created.
mkfs.ext4 /dev/vz/vz
mkdir /vz
mount /dev/vz/vz /vz
echo "/dev/vz/vz /vz ext4 defaults 1 1" >> /etc/fstab

Overall The result should be similar to the following one:

df -hT /vz
Filesystem Type Size Used Avail Use% Mounted on
/dev/mapper/vz-vz ext4 50G 827M 46G 2% /vz

Type must be ext4 and it must be me mounted on /vz.

Doing the conversion

Once /vz partition is prepared, we can go ahead with the conversion.

  1. Install python sub-processes, the latest OpenVZ 7 release, Epel repository, prctl utility, OpenVZ kernel and ploop packages:

    yum localinstall -y
    yum localinstall -y
    yum install epel-release -y
  2. Install vzlinux release:

    yum install python3 -y
    rpm -Uvh
    rpm -Uvh
    rpm -Uvh
  3. Move CentOS repositories to another location to avoid package conflicts in future:

    mv /etc/yum.repos.d/CentOS-* /root/
  4. Re-install json-c and jansson packages from virtuozzo repositories:

    rpm -e --nodeps --justdb json-c
    yum erase jansson -y
    yum localinstall -y
    yum localinstall -y
  5. Re-install nss packages:

    rpm -e --nodeps --justdb nspr nss nss-pem nss-softokn nss-softokn-freebl nss-sysinit nss-tools nss-util
    yum localinstall -y
    yum downgrade glibc*
    yum install nss-softokn-freebl.i686 nss-tools -y
  6. Install the necessary packages:

    yum install prlctl prl-disp-service vzkernel *ploop* -y && yum update -y
  7. If the action above fails with the error "Protected multilib versions: zlib-1.2.7-18.vl7.i686 != zlib-1.2.7-19.el7_9.x86_64", downgrade zlib package:

    yum downgrade zlib
  8. For OVH servers - update grub configuration:

    mkdir /boot/efi/EFI/virtuozzo
    mv /boot/efi/EFI/centos ~/
    grub2-set-default  1
    grub2-mkconfig -o /boot/efi/EFI/virtuozzo/grub.cfg
  9. Reboot the node:

  10. Enable ploop kernel modules:

    modprobe ploop pfmt_ploop1 pfmt_raw pio_direct
  11. Update the conversion script:

    wget -O /usr/libexec/ovz-template-converter && chmod +x /usr/libexec/ovz-template-converter
    rpm -e --nodeps --justdb python3-pip
    yum install -y python36-pip python-configobj && pip3 install configobj
  12. Install EZ packages:

    yum install -y *ez.noarch

There is a probability that mariadb-libs package is installed already on the server from CentOS 7 repositories. It will conflict with mariadb-* packages upon installation of SolusVM Master software. Check this as below and remove the package prior to installation of SolusVM Master software:

  1. Check if the package is installed:

    rpm -qa | grep mariadb-libs
  2. Remove the package:

    rpm -e --nodeps --justdb mariadb-libs

The conversion is done. Feel free to install SolusVM on it:

curl -o && sh
Back to top