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    For Dedicated Servers and Server Power Deals managed in the Cloud Panel

    In this article, you will learn how to use your Dedicated Servers Linux rescue system to back up the data of your server.

    Note

    How to boot your server into the Linux rescue system is explained in the following article:

    Booting the Dedicated Server to the Linux Rescue System

    Checking the Status of the Software RAID

    To check the status of the software RAID, enter the following command in the shell:

    rescue:~# cat /proc/mdstat

    After entering the command, the following information is displayed, for example:

    rescue:~# cat /proc/mdstat
    Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [faulty]
    md126 : active (auto-read-only) raid1 sda2[0] sdb2[2]
          29293440 blocks super 1.0 [2/2] [UU]

    md127 : active (auto-read-only) raid1 sda4[0] sdb4[2]
          937699136 blocks super 1.0 [2/2] [UU]
          bitmap: 0/7 pages [0KB], 65536KB chunk

    In the above example, md127 must be mounted.

    Important Information About Partitioning Your Dedicated Server

    On Dedicated Servers managed in the Cloud Panel, only one partition will be created during setup and when reinstalling the operating system as of 10/20/2021. On Dedicated Servers set up before this date and on Dedicated Servers purchased as part of a Server Power Deal, the operating system images include the Logical Volume Manager (LVM). The Logical Volume Manager places a logical layer between the file system and the partitions of the disks used. This makes it possible to create a file system that spans multiple partitions and/or disks. In this way, for example, the storage space of several partitions or disks can be combined.

    Display Partitioning

    To display a list of the file systems and identify the file system, enter the command df -h. The abbreviation df stands for disk free. The parameter -h allows you to display the number of occupied blocks in gigabytes, megabytes or kilobytes in a machine-readable form.

    rescue:~# df -h

    Example:

    rescue:~# df -h
    Filesystem      Size  Used Avail Use% Mounted on
    /dev/root       630M  560M   71M  89% /
    devtmpfs         16G     0   16G   0% /dev
    tmpfs            16G     0   16G   0% /dev/shm
    tmpfs            16G   14M   16G   1% /run
    tmpfs           5.0M     0  5.0M   0% /run/lock
    tmpfs            16G     0   16G   0% /sys/fs/cgroup

     

    To list the existing disks, partitions, logical volumes, and multiple devices, enter the command fdisk -l. fdisk is a command line program for partitioning hard disks. This program lets you display, create or delete partitions.

    rescue:~# fdisk -l

    Note

    Depending on the server type and server model, the displayed partitions, logical volumes, and multiple devices may differ.

    The following example lists information about hard disks, partitions, logical volumes, and multiple devices of a server with software raid. In this example, the server's operating system uses the Logical Volume Manager:

    rescue:~# fdisk -l
    Disk /dev/ram0: 640 MiB, 671088640 bytes, 1310720 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes

    Disk /dev/sda: 447.1 GiB, 480103981056 bytes, 937703088 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes
    Disklabel type: gpt
    Disk identifier: 857E5503-92EF-4576-B9E9-C1E9D6CB603F

    Device        Start       End   Sectors   Size Type
    /dev/sda1      2048      6143      4096     2M BIOS boot
    /dev/sda2      6144  58593279  58587136    28G Linux RAID
    /dev/sda3  58593280  78125055  19531776   9.3G Linux swap
    /dev/sda4  78125056 937701375 859576320 409.9G Linux RAID

    Disk /dev/sdb: 447.1 GiB, 480103981056 bytes, 937703088 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes
    Disklabel type: gpt
    Disk identifier: 3CDA280F-70D3-4EBF-AC09-1C94C23A3BB3

    Device        Start       End   Sectors   Size Type
    /dev/sdb1      2048      6143      4096     2M BIOS boot
    /dev/sdb2      6144  58593279  58587136    28G Linux RAID
    /dev/sdb3  58593280  78125055  19531776   9.3G Linux swap
    /dev/sdb4  78125056 937701375 859576320 409.9G Linux RAID

    Disk /dev/md127: 28 GiB, 29996482560 bytes, 58586880 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes

    Disk /dev/md126: 409.9 GiB, 440102879232 bytes, 859575936 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes

    Disk /dev/mapper/vg00-usr: 10 GiB, 10737418240 bytes, 20971520 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes

    Disk /dev/mapper/vg00-var: 10 GiB, 10737418240 bytes, 20971520 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes

    Disk /dev/mapper/vg00-home: 10 GiB, 10737418240 bytes, 20971520 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes

    Disk /dev/ram12: 640 MiB, 671088640 bytes, 1310720 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes

    Disk /dev/ram8: 640 MiB, 671088640 bytes, 1310720 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes

    Disk /dev/ram4: 640 MiB, 671088640 bytes, 1310720 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes

    Disk /dev/ram14: 640 MiB, 671088640 bytes, 1310720 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes

    Disk /dev/ram1: 640 MiB, 671088640 bytes, 1310720 sectors
    Units: sectors of 1 * 512 = 512 bytes
    Sector size (logical/physical): 512 bytes / 4096 bytes
    I/O size (minimum/optimal): 4096 bytes / 4096 bytes

    Make a note of the paths of the logical volumes or the multiple device. In this example it is /dev/md127.

    If only one partition is set up on your server, take note of the existing disk and partition.

    Finding the Mount Points

    • To view the mount points of the devices and partitions you are using, enter the following command:

      [root@localhost ~]# lsblk

      Then, information similar to the following example will be displayed:

      Dedicated Servers with HDD:

      [root@2A2E3A1 ~]# lsblk
      NAME    MAJ:MIN RM  SIZE RO TYPE  MOUNTPOINT
      sda       8:0    0  1.8T  0 disk
      ├─sda1    8:1    0  511M  0 part
      │ └─md1   9:1    0  511M  0 raid1 /boot/efi
      ├─sda2    8:2    0  1.4G  0 part
      │ └─md2   9:2    0  1.4G  0 raid1 /boot
      ├─sda3    8:3    0  3.7G  0 part  [SWAP]
      └─sda4    8:4    0  1.8T  0 part
        └─md4   9:4    0  1.8T  0 raid1 /
      sdb       8:16   0  1.8T  0 disk
      ├─sdb1    8:17   0  511M  0 part
      │ └─md1   9:1    0  511M  0 raid1 /boot/efi
      ├─sdb2    8:18   0  1.4G  0 part
      │ └─md2   9:2    0  1.4G  0 raid1 /boot
      ├─sdb3    8:19   0  3.7G  0 part  [SWAP]
      └─sdb4    8:20   0  1.8T  0 part
        └─md4   9:4    0  1.8T  0 raid1 /

      Dedicated Servers with NVMe:

      rescue:~# lsblk
      NAME        MAJ:MIN RM   SIZE RO TYPE  MOUNTPOINT
      sda           8:0    0 447.1G  0 disk
      sdb           8:16   0 447.1G  0 disk
      nvme1n1     259:0    0 894.3G  0 disk
      ├─nvme1n1p1 259:6    0   511M  0 part
      │ └─md124     9:124  0 510.9M  0 raid1
      ├─nvme1n1p2 259:7    0   1.4G  0 part
      │ └─md125     9:125  0   1.4G  0 raid1
      ├─nvme1n1p3 259:8    0   3.7G  0 part
      │ └─md126     9:126  0   3.7G  0 raid1
      └─nvme1n1p4 259:9    0 888.7G  0 part
        └─md127     9:127  0 888.5G  0 raid1 
      nvme0n1     259:1    0 894.3G  0 disk
      ├─nvme0n1p1 259:2    0   511M  0 part
      │ └─md124     9:124  0 510.9M  0 raid1
      ├─nvme0n1p2 259:3    0   1.4G  0 part
      │ └─md125     9:125  0   1.4G  0 raid1
      ├─nvme0n1p3 259:4    0   3.7G  0 part
      │ └─md126     9:126  0   3.7G  0 raid1
      └─nvme0n1p4 259:5    0 888.7G  0 part
        └─md127     9:127  0 888.5G  0 raid1

    • Make a note of the devices and partitions and their mount points.

    Starting the Logical Volume Management Manually

    Usually all logical volumes are started when the rescue system is started. If these are not active, you can start the logical volumes manually. To do this, enter the following commands:

    rescue:~# pvscan
    rescue:~# vgscan
    rescue:~# vgchange -a y

    File System Check

    Before you mount the logical volume or multiple device, you should check consistency of the file system using File System Check (FSCK). 

    Caution

    A file system check must not be performed with mounted and/or encrypted partitions, as this can result in data loss. If you check the file system of a logical volume or multiple device, it may also not be mounted.

    Therefore, make sure that the partition, logical volume, or multiple device is not mounted or encrypted before checking it with the File System Check.

    To check a partition, logical volume, or multiple device using the File System Check, type the following command:

    Partition

    rescue:/# fsck -f /PATH/PARTITION

    Logical Volume

    rescue:/# fsck -f /PATH/LOGICAL_VOLUME

    Multiple device

    rescue:/# fsck -f /PATH/MULTIPLE_DEVICE

    The following example checks the file system of md127:

    rescue:/# fsck -f /dev/md127
    fsck from util-linux 2.29.2
    e2fsck 1.43.4 (31-Jan-2017)
    Pass 1: Checking inodes, blocks, and sizes
    Pass 2: Checking directory structure
    Pass 3: Checking directory connectivity
    Pass 4: Checking reference counts
    Pass 5: Checking group summary information
    root: 4026/1831424 files (1.7% non-contiguous), 190579/7323360 blocks

    Mounting a Multiple Device or a Logical Volume

    • To create the directory in which to mount the logical volume or multiple device, type the following command:

      rescue:/# mkdir /mnt/DIRECTORY_NAME

      Example:

      rescue:/# mkdir /mnt/md127

    • To mount the logical volume or multiple device, type the following command:

      rescue:/# mount /PATH/PARTITION /mnt/DIRECTORY

      Dedicated Servers with HDD:

      rescue:/# mount /dev/md127 /mnt/md4

      Dedicated Servers with NVMe:

      rescue:/# mount /dev/md127 /mnt/md127

    Backing up Files

    You have the following options to back up the data of your server:

    • You save the data on your local computer using WinSCP.

    • You save the data on another server using Secure Copy.

    After backing up your data, you can install a new image on the server or restore a backup of your system. Then you can copy the saved data to the server.


    Backup Data to a Local Computer Using WinSCP

    If you are using WinSCP to back up your data to a local computer, you can select the desired data and drag and drop it to a directory on your local computer.


    Copy Data to Another Server Using Secure Copy

    Secure Copy is an encrypted data transfer protocol based on Secure Shell. To transfer the data, enter the following command in the shell:

    scp -r /PATH/LIST username@IP-ADRESS:/PATH/DESTINATION LIST

    Example:

    scp -r /mnt root@82.165.69.130:/home/backup

    Unmounting the file systems

    Before you boot the server into the normal mode, you need to unmount the mounted logical volumes or multiple devices. To do this, use the umount command.

    Caution

    If you restart the server with mounted file systems, data loss may occur!

    To unmount the mounted logical volumes or partitions, enter the following command:

    rescue:/# umount /PATH/MULTIPLE_DEVICE /mnt/DIRECTORY

    or

    rescue:/# umount /PATH/LOGICAL_VOLUME /mnt/DIRECTORY

    In the following example a Multiple Device is unmounted:

    rescue:/# mount /dev/md127 /mnt/md127