When optimizing a Linux private image, you need to install native Xen and KVM drivers for the image.
If you do not install Xen drivers for the image, the network performance of the ECSs created from this image will be poor, and the security groups and firewall configured for the ECSs will not take effect.
If you do not install KVM drivers for the image, the NICs of the ECSs may not be detected and the ECSs will be unable to communicate with other resources.
This section describes how to install native Xen and KVM drivers.
Take CentOS 7.0 as an example. Modify the /etc/dracut.conf file. Add the xen-pv and VirtIO drivers to add_drivers. xen-pv drivers include xen-blkfront and xen-netfront. VirtIO drivers include virtio_blk, virtio_scsi, virtio_net, virtio_pci, virtio_ring, and virtio. Separate driver names with spaces. Save and exit the /etc/dracut.conf file. Run the dracut -f command to regenerate initrd.
For details, see CentOS and EulerOS.
Modify the /etc/initramfs-tools/modules file. Add the xen-pv and VirtIO drivers. xen-pv drivers include xen-blkfront and xen-netfront. VirtIO drivers include virtio_blk, virtio_scsi, virtio_net, virtio_pci, virtio_ring, and virtio. Separate driver names with spaces. Save and exit the /etc/initramfs-tools/modules file. Run the update-initramfs -u command to regenerate initrd.
For details, see Ubuntu and Debian.
For SUSE, run the following command to check whether xen-kmp (driver package for xen-pv) is installed:
rpm -qa |grep xen-kmp
If information similar to the following is displayed, xen-kmp is installed in the OS:
xen-kmp-default-4.2.2_04_3.0.76_0.11-0.7.5
If xen-kmp is not installed, obtain it from the ISO file and install it.
If you add built-in drivers to the initrd or initramfs file by mistake, the ECS will not be affected.
vi /etc/dracut.conf
[root@CTU10000xxxxx ~]# vi /etc/dracut.conf # additional kernel modules to the default add_drivers+="xen-blkfront xen-netfront virtio_blk virtio_scsi virtio_net virtio_pci virtio_ring virtio" ......
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.
lsinitrd /boot/initramfs-`uname -r`.img | grep xen
lsinitrd /boot/initramfs-`uname -r`.img | grep virtio
If the virtual file system is initrd, run the following commands to check whether native Xen and KVM drivers have been loaded:
lsinitrd /boot/initrd-`uname -r` | grep xen
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 xen -rwxr--r-- 1 root root 54888 Jul 16 17:53 lib/modules/2.6.32-573.8.1.el6.x86_64/kernel/drivers/block/xen-blkfront.ko -rwxr--r-- 1 root root 45664 Jul 16 17:53 lib/modules/2.6.32-573.8.1.el6.x86_64/kernel/drivers/net/xen-netfront.ko [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 commands to check whether built-in drivers are in the kernel:
cat /boot/config-`uname -r` | grep CONFIG_VIRTIO | grep y
cat /boot/config-`uname -r` | grep CONFIG_XEN | grep y
vi /etc/initramfs-tools/modules
[root@CTU10000xxxxx ~]#vi /etc/initramfs-tools/modules ...... # Examples: # # raid1 # sd_mOd xen-blkfront xen-netfront virtio_blk virtio_scsi virtio_net virtio_pci virtio_ring virtio
lsinitramfs /boot/initrd.img-`uname -r` |grep xen
lsinitramfs /boot/initrd.img-`uname -r` |grep virtio
[root@ CTU10000xxxxx home]# lsinitramfs /boot/initrd.img-`uname -r` |grep xen lib/modules/3.5.0-23-generic/kernel/drivers/net/ethernet/qlogic/netxen lib/modules/3.5.0-23-generic/kernel/drivers/net/ethernet/qlogic/netxen/netxen_nic.ko lib/modules/3.5.0-23-generic/kernel/drivers/net/xen-netback lib/modules/3.5.0-23-generic/kernel/drivers/net/xen-netback/xen-netback.ko lib/modules/3.5.0-23-generic/kernel/drivers/block/xen-blkback lib/modules/3.5.0-23-generic/kernel/drivers/block/xen-blkback/xen-blkback.ko [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 commands to check whether built-in drivers are 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 [root@ CTU10000xxxxx home]# cat /boot/config-`uname -r` | grep CONFIG_XEN | grep y CONFIG_XEN_BLKDEV_FRONTEND=y CONFIG_XEN_NETDEV_FRONTEND=y
If the OS version is earlier than SUSE 12 SP1 or openSUSE 13, modify the /etc/sysconfig/kernel file. For details, see scenario 1.
If the OS version is SUSE 12 SP1, modify the /etc/dracut.conf file and add xen-pv and VirtIO drivers. For details, see scenario 2.
For SUSE, run the following command to check whether xen-kmp (driver package for xen-pv) is installed in the OS:
rpm -qa |grep xen-kmp
If information similar to the following is displayed, xen-kmp is installed:
xen-kmp-default-4.2.2_04_3.0.76_0.11-0.7.5
If xen-kmp is not installed, obtain it from the installation ISO and install it first.
vi etc/sysconfig/kernel
SIA10000xxxxx:~ # vi /etc/sysconfig/kernel # (like drivers for scsi-controllers, for lvm or reiserfs) # INITRD_MODULES="ata_piix ata_generic xen_vnif xen_vbd xen_platform_pci virtio_blk virtio_scsi virtio_net virtio_pci virtio_ring virtio"
If the virtual file system is not the default initramfs or initrd, 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 menu.lst or grub.cfg file (/boot/grub/menu.lst, /boot/grub/grub.cfg, or /boot/grub2/grub.cfg).
The following is an example initrd file of SUSE 11 SP4:
default 0 timeout 10 gfxmenu (hd0,0)/boot/message title sles11sp4_001_[_VMX_] root (hd0,0) kernel /boot/linux.vmx vga=0x314 splash=silent console=ttyS0,115200n8 console=tty0 net.ifnames=0 NON_PERSISTENT_DEVICE_NAMES=1 showopts initrd /boot/initrd.vmx title Failsafe_sles11sp4_001_[_VMX_] root (hd0,0) kernel /boot/linux.vmx vga=0x314 splash=silent ide=nodma apm=off noresume edd=off powersaved=off nohz=off highres=off processsor.max+cstate=1 nomodeset x11failsafe console=ttyS0,115200n8 console=tty0 net.ifnames=0 NON_PERSISTENT_DEVICE_NAMES=1 showopts initrd /boot/initrd.vmx
/boot/initrd.vmx in the initrd line is the initrd file actually used. Run the dracut -f /boot/initrd.vmx command. If the initrd file does not contain the /boot directory, such as /initramfs-xxx, run the dracut -f /boot/initramfs-xxx command.
lsinitrd /boot/initrd-`uname -r` | grep xen
SIA10000xxxxx:~ # lsinitrd /boot/initrd-`uname -r` | grep xen -rwxr--r-- 1 root root 42400 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/block/xen-blkfront.ko -rwxr--r-- 1 root root 44200 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/net/xen-netfront.ko SIA10000xxxxx:~ # lsinitrd /boot/initrd-`uname -r` | grep virtio -rwxr--r-- 1 root root 19248 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/scsi/virtio_scsi.ko -rwxr--r-- 1 root root 23856 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/block/virtio_blk.ko drwxr-xr-x 2 root root 0 Jul 12 14:53 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/virtio -rwxr--r-- 1 root root 15848 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/virtio/virtio_ring.ko -rwxr--r-- 1 root root 20008 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/virtio/virtio_pci.ko -rwxr--r-- 1 root root 12272 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/virtio/virtio.ko -rwxr--r-- 1 root root 38208 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/net/virtio_net.ko
Before the modification:
###Don't change this comment -YaST2 identifier: Original name: linux### title SUSE Linux Enterprise Server 11SP4 - 3.0.76-0.11 (default) root (hd0,0) kernel /boot/vmlinuz-3.0.76-0.11-default root=UUID=4eb40294-4c6f-4384-bbb6-b8795bbb1130 splash=silentcrashkernel=256M-:128M showopts vga=0x314 initrd /boot/initrd-3.0.76-0.11-default
After the modification:
###Don't change this comment -YaST2 identifier: Original name: linux### title SUSE Linux Enterprise Server 11SP4 - 3.0.76-0.11 (default) root (hd0,0) kernel /boot/vmlinuz-3.0.76-0.11-default root=UUID=4eb40294-4c6f-4384-bbb6-b8795bbb1130 splash=silentcrashkernel=256M-:128M showopts vga=0x314 xen_platform_pci.dev_unplug=all initrd /boot/initrd-3.0.76-0.11-default
lsinitrd /boot/initrd-`uname -r` | grep xen
lsinitrd /boot/initrd-`uname -r` | grep virtio
SIA10000xxxxx:~ # lsinitrd /boot/initrd-`uname -r` | grep xen -rwxr--r-- 1 root root 42400 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/block/xen-blkfront.ko -rwxr--r-- 1 root root 44200 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/net/xen-netfront.ko SIA10000xxxxx:~ # lsinitrd /boot/initrd-`uname -r` | grep virtio -rwxr--r-- 1 root root 19248 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/scsi/virtio_scsi.ko -rwxr--r-- 1 root root 23856 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/block/virtio_blk.ko drwxr-xr-x 2 root root 0 Jul 12 14:53 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/virtio -rwxr--r-- 1 root root 15848 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/virtio/virtio_ring.ko -rwxr--r-- 1 root root 20008 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/virtio/virtio_pci.ko -rwxr--r-- 1 root root 12272 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/virtio/virtio.ko -rwxr--r-- 1 root root 38208 Jun 22 2012 lib/modules/2.6.32-279.el6.x86_64/kernel/drivers/net/virtio_net.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 commands to check whether built-in drivers are in the kernel:
cat /boot/config-`uname -r` | grep CONFIG_VIRTIO | grep y
cat /boot/config-`uname -r` | grep CONFIG_XEN | grep y
vi /etc/dracut.conf
[root@CTU10000xxxxx ~]# vi /etc/dracut.conf # additional kernel modules to the default add_drivers+="ata_piix ata_generic xen_vnif xen_vbd xen_platform_pci virtio_blk virtio_scsi virtio_net virtio_pci virtio_ring virtio"
dracut -f /boot/initramfs-File name
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.
lsinitrd /boot/initramfs-`uname -r`.img | grep xen
lsinitrd /boot/initramfs-`uname -r`.img | grep virtio
If the virtual file system is initrd, run the following commands to check whether native Xen and KVM drivers have been loaded:
lsinitrd /boot/initrd-`uname -r` | grep xen
lsinitrd /boot/initrd-`uname -r` | grep virtio
vi /etc/dracut.conf
[root@CTU10000xxxxx ~]# vi /etc/dracut.conf # additional kernel modules to the default add_drivers+="ata_piix ata_generic xen-blkfront xen-netfront virtio_blk virtio_scsi virtio_net virtio_pci virtio_ring virtio"
dracut -f /boot/initramfs-File name
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.
lsinitrd /boot/initramfs-`uname -r`.img | grep xen
lsinitrd /boot/initramfs-`uname -r`.img | grep virtio
If the virtual file system is initrd, run the following commands to check whether the native Xen and KVM driver modules are successfully loaded:
lsinitrd /boot/initrd-`uname -r` | grep xen
lsinitrd /boot/initrd-`uname -r` | grep virtio
Assume that the virtual file system is initrd. The following command output will be displayed:
sluo-ecs-30dc:~ # lsinitrd /boot/initrd-`uname -r` | grep xen -rw-r--r-- 1 root root 69575 Oct 26 2016 lib/modules/4.4.21-69-default/kernel/drivers/block/xen-blkfront.ko -rw-r--r-- 1 root root 53415 Oct 26 2016 lib/modules/4.4.21-69-default/kernel/drivers/net/xen-netfront.ko drwxr-xr-x 2 root root 0 Sep 28 10:21 lib/modules/4.4.21-69-default/updates/pvdriver/xen-hcall -rwxr-xr-x 1 root root 8320 Sep 28 10:21 lib/modules/4.4.21-69-default/updates/pvdriver/xen-hcall/xen-hcall.ko sluo-ecs-30dc:~ # lsinitrd /boot/initrd-`uname -r` | grep virtio -rw-r--r-- 1 root root 29335 Oct 26 2016 lib/modules/4.4.21-69-default/kernel/drivers/block/virtio_blk.ko -rw-r--r-- 1 root root 57007 Oct 26 2016 lib/modules/4.4.21-69-default/kernel/drivers/net/virtio_net.ko -rw-r--r-- 1 root root 32415 Oct 26 2016 lib/modules/4.4.21-69-default/kernel/drivers/scsi/virtio_scsi.ko drwxr-xr-x 2 root root 0 Sep 28 10:21 lib/modules/4.4.21-69-default/kernel/drivers/virtio -rw-r--r-- 1 root root 19623 Oct 26 2016 lib/modules/4.4.21-69-default/kernel/drivers/virtio/virtio.ko -rw-r--r-- 1 root root 38943 Oct 26 2016 lib/modules/4.4.21-69-default/kernel/drivers/virtio/virtio_pci.ko -rw-r--r-- 1 root root 24431 Oct 26 2016 lib/modules/4.4.21-69-default/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 commands to check whether built-in drivers are in the kernel:
cat /boot/config-`uname -r` | grep CONFIG_VIRTIO | grep y
cat /boot/config-`uname -r` | grep CONFIG_XEN | grep y