Installing Native KVM Drivers on a KVM ECS

Scenarios

Before using a KVM ECS to create a private image, you need to install native KVM drivers on the ECS. If the drivers have been installed, skip this section.

If you do not install KVM drivers, NICs of the ECS may not be detected and the ECS cannot communicate with other resources.

Prerequisites

• The virtualization type of the ECS is KVM.

  You can run the following command to check the virtualization type of an ECS:

  lscpu

  • If the value of Hypervisor vendor is XEN, install drivers as instructed in Installing Native Xen and KVM Drivers on a Xen ECS.
  • If the value of Hypervisor vendor is KVM, install drivers as instructed in this section.
• No native KVM drivers are installed on the ECS.
  1. Check whether VirtIO drivers are installed. The command varies depending on the OS.
     • CentOS/EulerOS

       If the root filesystem is mounted by initramfs, run the following command:

       lsinitrd /boot/initramfs-`uname -r`.img | grep virtio

       If the root filesystem is mounted by initrd, run the following command:

       lsinitrd /boot/initrd-`uname -r` | grep virtio

     • Ubuntu/Debian

       lsinitramfs /boot/initrd.img-`uname -r` |grep virtio

     • SUSE/openSUSE
       • SUSE 12 SP1/openSUSE 13 or earlier:

         lsinitrd /boot/initrd-`uname -r` | grep virtio

       • SUSE 12 SP1 or later than SUSE 12 SP1/openSUSE 13:

         If the root filesystem is mounted by initramfs, run the following command:

         lsinitrd /boot/initramfs-`uname -r`.img | grep virtio

         If the root filesystem is mounted by initrd, run the following command:

         lsinitrd /boot/initrd-`uname -r` | grep virtio

     If VirtIO drivers have been installed, skip this section.

     

     If VirtIO drivers have not been installed, install them as instructed in this section.

• The ECS kernel must be later than 2.6.24.
• Disable your antivirus and intrusion detection software. You can enable the software after KVM drivers are installed.
• You have performed operations in Changing Disk Identifiers in the GRUB File to UUID and Changing Disk Identifiers in the fstab File to UUID.

Procedure

Modify the configuration file based on the OS version.

CentOS and EulerOS

1. Run the following command to open the /etc/dracut.conf file:

   vi /etc/dracut.conf

2. Press i to enter the editing mode and add VirtIO drivers to add_drivers (the format varies depending on the OS).

   [root@CTU10000xxxxx ~]# vi /etc/dracut.conf 
   # additional kernel modules to the default 
   add_drivers+="virtio_blk virtio_scsi virtio_net virtio_pci virtio_ring virtio" 
   ....

3. Press Esc, enter :wq, and press Enter. The system saves the change and exits the /etc/dracut.conf file.
4. Run the following command to regenerate initrd:

   dracut -f /boot/initramfs-2.6.32-573.8.1.el6.x86_64.img

   If the virtual file system is not the default initramfs, run the dracut -f Name of the initramfs or initrd file actually used command. The actual initramfs or initrd file name can be obtained from the grub.cfg file, which can be /boot/grub/grub.cfg, /boot/grub2/grub.cfg, or /boot/grub/grub.conf depending on the OS.

5. If the virtual file system is initramfs, run the following command to check whether native KVM drivers have been installed:

   lsinitrd /boot/initramfs-`uname -r`.img | grep virtio

   If the virtual file system is initrd, run the following command to check whether native KVM drivers have been installed:

   lsinitrd /boot/initrd-`uname -r` | grep virtio

   Assume that the virtual file system is initramfs. The following command output will be displayed:

   [root@CTU10000xxxxx home]# lsinitrd /boot/initramfs-`uname -r`.img | grep virtio 
   -rwxr--r--   1 root     root        23448 Jul 16 17:53 lib/modules/2.6.32-573.8.1.el6.x86_64/kernel/drivers/block/virtio_blk.ko 
   -rwxr--r--   1 root     root        50704 Jul 16 17:53 lib/modules/2.6.32-573.8.1.el6.x86_64/kernel/drivers/net/virtio_net.ko 
   -rwxr--r--   1 root     root        28424 Jul 16 17:53 lib/modules/2.6.32-573.8.1.el6.x86_64/kernel/drivers/scsi/virtio_scsi.ko 
   drwxr-xr-x   2 root     root            0 Jul 16 17:53 lib/modules/2.6.32-573.8.1.el6.x86_64/kernel/drivers/virtio 
   -rwxr--r--   1 root     root        14544 Jul 16 17:53 lib/modules/2.6.32-573.8.1.el6.x86_64/kernel/drivers/virtio/virtio.ko 
   -rwxr--r--   1 root     root        21040 Jul 16 17:53 lib/modules/2.6.32-573.8.1.el6.x86_64/kernel/drivers/virtio/virtio_pci.ko 
   -rwxr--r--   1 root     root        18016 Jul 16 17:53 lib/modules/2.6.32-573.8.1.el6.x86_64/kernel/drivers/virtio/virtio_ring.ko

   

   If you add built-in drivers to the initrd or initramfs file, the ECS will not be affected. This makes it easy to modify the drivers. However, you cannot check the drivers by running the lsinitrd command. You can run the following command to check whether the drivers are built-in ones in the kernel:

   cat /boot/config-`uname -r` | grep CONFIG_VIRTIO | grep y

Ubuntu and Debian

1. Run the following command to open the modules file:

   vi /etc/initramfs-tools/modules

2. Press i to enter the editing mode and add VirtIO drivers to the /etc/initramfs-tools/modules file (the format varies depending on the OS).

   [root@CTU10000xxxxx ~]#vi /etc/initramfs-tools/modules 
   ...
   # Examples: 
   # 
   # raid1 
   # sd_mOd 
   virtio_blk
   virtio_scsi
   virtio_net
   virtio_pci
   virtio_ring
   virtio

3. Press Esc, enter :wq, and press Enter. The system saves the change and exits the /etc/initramfs-tools/modules file.
4. Run the following command to regenerate initrd:

   update-initramfs -u

5. Run the following command to check whether native KVM drivers have been installed:

   lsinitramfs /boot/initrd.img-`uname -r` |grep virtio

   [root@ CTU10000xxxxx home]# lsinitramfs /boot/initrd.img-`uname -r` |grep virtio 
   lib/modules/3.5.0-23-generic/kernel/drivers/scsi/virtio_scsi.ko

   

   If you add built-in drivers to the initrd or initramfs file, the ECS will not be affected. This makes it easy to modify the drivers. However, you cannot check the drivers by running the lsinitrd command. You can run the following command to check whether the drivers are built-in ones in the kernel:

   [root@ CTU10000xxxxx home]# cat /boot/config-`uname -r` | grep CONFIG_VIRTIO | grep y
   CONFIG_VIRTIO_BLK=y
   CONFIG_VIRTIO_NET=y
   CONFIG_VIRTIO=y
   CONFIG_VIRTIO_RING=y
   CONFIG_VIRTIO_PCI=y
   CONFIG_VIRTIO_MMIO_CMDLINE_DEVICES=y

SUSE and openSUSE (Earlier than SUSE 12 SP1 or openSUSE 13)

SUSE and openSUSE (SUSE 12 SP1)

SUSE and openSUSE (Later than SUSE 12 SP1 or openSUSE 13)

Modify the /etc/dracut.conf file.

Follow-up Procedure

Delete log files, historical records, and other data.

1. Delete unnecessary key files.

   echo > /$path/$to/$root/.ssh/authorized_keys

   Example: echo > /root/.ssh/authorized_keys

   echo > /$path/$to/$none-root/.ssh/authorized_keys

   Example: echo > /home/linux/.ssh/authorized_keys

2. Delete log files from the /var/log directory.

   rm -rf /var/log/*

   

   Before deleting log files, back up log directories and log files required by application startup. For example, if the default Nginx log directory /var/log/nginx is deleted, Nginx may fail to be started.

3. Delete historical records.

   echo > /root/.bash_history

   history -c