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diff --git a/docs/operation/md-raid.md b/docs/operation/md-raid.md new file mode 100644 index 00000000..bd0f9a69 --- /dev/null +++ b/docs/operation/md-raid.md @@ -0,0 +1,236 @@ +--- +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: + +```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: + +```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. + +```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. + +```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. + +```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: + +```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: + +```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. + +```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. + +```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 \<RAID‐1‐device\> member \<disk‐partition\> + ``` + 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 \<disk‐device1\> like \<disk‐device2\> + ``` + 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 \<RAID‐1‐device\> member \<disk‐partition\> + ``` + 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 \<RAID‐1‐device\> member \<disk‐partition\> + + 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 \<disk‐device1\> like \<disk‐device2\> + +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 \<RAID‐1‐device\> + +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 +::: +```
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