:lastproofread: 2025-11-20 .. _raid: ###### RAID 1 ###### A Redundant Array of Independent Disks (RAID) uses two or more hard disk drives to improve disk speed, store more data, and/or provide fault tolerance. There are several storage schemes possible in a RAID array, each offering a different combination of storage, reliability, and performance. VyOS supports **RAID 1** deployments. RAID 1 uses two or more disks that mirror one another to provide system fault tolerance. In a RAID 1 configuration, every sector on one disk is duplicated on every sector of all disks in the array. Provided even one disk in the RAID 1 set is operational, the system continues to run, even through disk replacement (provided that the hardware supports in-service replacement of drives). RAID 1 can be implemented using special hardware or it can be implemented in software. VyOS supports software RAID 1 on two disks. The VyOS implementation of RAID 1 features the following: * Detection and reporting of disk failure. * Maintain system operation with one failed disk. * Boot the system with one failed disk. * Replace a failed disk and initiate re-mirroring. * Monitor the status of re-mirroring. .. _raid_installation: Installation implications ========================= The VyOS installation utility provides several options for installing to a RAID 1 set. You can: * Use the install system to create the RAID 1 set. * Use the built-in Linux commands to create a RAID 1 set before running the install system command. * Use a previously-created RAID 1 set. .. note:: Before a permanent installation, VyOS runs a live installation. Configuration ============= Standard installation on a single disk -------------------------------------- VyOS automatically detects the presence of two or more disks that are not currently part of a RAID array when installed. The VyOS installation utility automatically offers you the option to configure RAID 1 mirroring for eligible drives with the following prompt: .. code-block:: none Would you like to configure RAID 1 mirroring on them? * If you do not want to configure RAID 1 mirroring, enter **No** at the prompt. Empty 2+ disk ------------- If VyOS detects two identical disks that are not currently part of a RAID 1 set, the VyOS installation utility automatically offers the option to configure RAID 1 mirroring for the drives with the following prompt: .. code-block:: none Would you like to configure RAID 1 mirroring on them? 1. To create a new RAID 1 array, enter **Yes** at the prompt. If VyOS detects a filesystem on the partitions being used for RAID 1, it will prompt you to indicate whether you want to continue creating the RAID 1 array. .. code-block:: none Continue creating array? 2. To overwrite the old filesystem, enter **Yes**. 3. The system informs you that all data on both drives will be erased. Confirm you want to continue. .. code-block:: none Are you sure you want to do this? 4. Enter **Yes** at the prompt to retain the current VyOS configuration. Enter **No** to delete the current VyOS configuration. .. code-block:: none Would you like me to save the data on it before I delete it? 5. Enter **Yes** at the prompt to retain the current VyOS configuration. Enter **No** to delete the current VyOS configuration. 6. Continue installing VyOS. Preexisting RAID 1 configuration -------------------------------- When VyOS detects a previously configured RAID 1 set, the installation utility displays the following prompt: .. code-block:: none Would you like to use this one? 1. To break up the current RAID 1 set, enter **No** at the prompt. The installation utility detects that there are two identical disks and offers you the option of configuring RAID 1 mirroring with the following prompt: .. code-block:: none Would you like to configure RAID 1 mirroring on them? 2. To decline to set up a new RAID 1 configuration on the disks, enter **No** at the prompt. VyOS prompts you to indicate which partition you would like the system installed on. .. code-block:: none Which partition should I install the root on? [sda1]: 3. Enter the partition where you would like the system installed. The system then prompts you to indicate whether you want to save the old configuration data. This represents the current VyOS configuration. .. code-block:: none Would you like me to save the data on it before I delete it? 4. Enter **Yes** at the prompt to retain the current VyOS configuration once installation is complete. Enter **No** to delete the current VyOS configuration. 5. Continue installing VyOS. Detecting and replacing a failed RAID 1 disk -------------------------------------------- VyOS system detects disk failures within a RAID 1 set and reports them to the system console. You can verify the failure by running the ``show raid`` command. To replace a bad disk within a RAID 1 set: 1. Remove the failed disk from the RAID 1 set: .. opcmd:: delete raid member where ``RAID-1-device`` is the name of the RAID 1 device. For example, ``md0`` and ``disk-partition`` is the name of the failed disk partition. For example, ``sdb2``. 2. Physically remove the failed disk from the system. If the drives are not hot-swappable, then you must shut down the system before removing the disk. 3. Replace the failed drive with a drive of the same size or larger. 4. Format the new disk for RAID 1 by running the following command: .. opcmd:: format disk like where ``disk-device1`` is the replacement disk. For example, ``sdb`` and ``disk-device2`` is the existing healthy disk. For example, ``sda``. 5. Add the replacement disk to the RAID 1 set by running the following command: .. opcmd:: add raid member where ``RAID-1-device`` is the name of the RAID 1 device. For example, ``md0`` and ``disk-partition`` is the name of the replacement disk partition. For example, ``sdb2``. Operation ========= Learn how to add a disk partition to a RAID 1 set, initiate mirror synchronization, and check and display information. .. opcmd:: add raid member Use this command to add a member disk partition to the RAID 1 set. Adding a disk partition to a RAID 1 set initiates mirror synchronization, where all data on the existing member partition is copied to the new partition. .. opcmd:: format disk like This command is typically used to prepare a disk to be added to a preexisting RAID 1 set (of which ``disk-device2`` is already a member). .. opcmd:: show raid shows output for ``show raid md0`` as ``sdb1`` is being added to the RAID 1 set and is in the process of being resynchronized. .. code-block:: none vyos@vyos:~$ show raid md0 /dev/md0:       Version : 00.90 Creation Time : Wed Oct 29 09:19:09 2008    Raid Level : raid1    Array Size : 1044800 (1020.48 MiB 1069.88 MB) Used Dev Size : 1044800 (1020.48 MiB 1069.88 MB)  Raid Devices : 2 Total Devices : 2 Preferred Minor : 0   Persistence : Superblock is persistent   Update Time : Wed Oct 29 19:34:23 2008         State : active, degraded, recovering Active Devices : 1 Working Devices : 2 Failed Devices : 0 Spare Devices : 1 Rebuild Status : 17% complete          UUID : 981abd77:9f8c8dd8:fdbf4de4:3436c70f        Events : 0.103   Number   Major   Minor   RaidDevice State      0       8        1        0      active sync   /dev/sda1      2       8       17        1      spare rebuilding   /dev/sdb1 .. opcmd:: show disk sda format Use this command to display the formatting of a hard disk. .. code-block:: none vyos@vyos:~$ show disk sda format Disk /dev/sda: 1073 MB, 1073741824 bytes 85 heads, 9 sectors/track, 2741 cylinders Units = cylinders of 765 * 512 = 391680 bytes Disk identifier: 0x000b7179  Device Boot      Start         End      Blocks   Id  System /dev/sda1               6        2737     1044922+  fd  Linux raid autodetect