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  6. What Can I Do If the Disks of the ECS Created Using a CentOS Image Cannot Be Found?

What Can I Do If the Disks of the ECS Created Using a CentOS Image Cannot Be Found?

This is because the xen-blkfront.ko module is not loaded upon ECS startup. You need to modify OS kernel boot parameters.

Log in to the ECS using VNC.

The page shown in Figure 1 is displayed.

Figure 1 VNC login page
NOTE:

This step must be performed after the OS starts. It is recommended that you modify kernel boot parameters in the ECS used for creating the image.

Perform the following operations to modify OS kernel boot parameters:

  1. Run the following command to log in to the OS:
    lsinitrd /boot/initramfs-`uname -r`.img |grep -i xen
    • If the command output contains xen-blkfront.ko, contact customer service.
    • If no command output is displayed, go to 2.
  1. Back up the original grub.conf configuration file.
    • If the ECS runs CentOS 6, run the following command:

      cp /boot/grub/grub.conf /boot/grub/grub.conf.bak

    • If the ECS runs CentOS 7, run the following command:

      cp /boot/grub2/grub.cfg /boot/grub2/grub.cfg.bak

  1. Use the vi editor to open the GRUB configuration file. Run the following command (using CentOS 7 as an example):

    vi /boot/grub2/grub.cfg

  2. Add xen_emul_unplug=all to the default boot kernel.
    NOTE:

    Search for the line that contains root=UUID= and add xen_emul_unplug=all to the end of the line.

menuentry 'CentOS Linux (3.10.0-229.el7.x86_64) 7 (Core) with debugging' --class rhel fedora --class gnu-linux --class gnu --class os --unrestricted $menuentry_id_option 'gnulinux-3.10.0-229.el7.x86_64-advanced-bf3cc825-7638-48d8-8222-cd2f412dd0de' {
        load_video
        set gfxpayload=keep
        insmod gzio
        insmod part_msdos
        insmod ext2
        set root='hd0,msdos1'
        if [ x$feature_platform_search_hint = xy ]; then
          search --no-floppy --fs-uuid --set=root --hint='hd0,msdos1'  bf3cc825-7638-48d8-8222-cd2f412dd0de
        else
          search --no-floppy --fs-uuid --set=root bf3cc825-7638-48d8-8222-cd2f412dd0de
        fi
        linux16 /boot/vmlinuz-3.10.0-229.el7.x86_64 root=UUID=bf3cc825-7638-48d8-8222-cd2f412dd0de xen_emul_unplug=all ro crashkernel=auto rhgb quiet  systemd.log_level=debug systemd.log_target=kmsg
        initrd16 /boot/initramfs-3.10.0-229.el7.x86_64.img
}
  1. Press Esc, enter :wq, and press Enter to exit the vi editor.
  2. Create an image using the ECS, upload the created image, and register the image as a private image on the cloud platform.