From 47e6f7423b9196ad6832d26cae52b7015f81ee7f Mon Sep 17 00:00:00 2001 From: David Sterba Date: Fri, 2 Mar 2018 22:56:53 +0100 Subject: btrfs: add support for 3-copy replication (raid1c3) Add new block group profile to store 3 copies in a simliar way that current RAID1 does. The profile attributes and constraints are defined in the raid table and used by the same code that already handles the 2-copy RAID1. The minimum number of devices is 3, the maximum number of devices/chunks that can be lost/damaged is 2. Like RAID6 but with 33% space utilization. Signed-off-by: David Sterba --- fs/btrfs/ctree.h | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) (limited to 'fs/btrfs/ctree.h') diff --git a/fs/btrfs/ctree.h b/fs/btrfs/ctree.h index 1c8f01eaf27c..aa1b437fb951 100644 --- a/fs/btrfs/ctree.h +++ b/fs/btrfs/ctree.h @@ -57,9 +57,9 @@ struct btrfs_ref; * filesystem data as well that can be used to read data in order to repair * read errors on other disks. * - * Current value is derived from RAID1 with 2 copies. + * Current value is derived from RAID1C3 with 3 copies. */ -#define BTRFS_MAX_MIRRORS (2 + 1) +#define BTRFS_MAX_MIRRORS (3 + 1) #define BTRFS_MAX_LEVEL 8 -- cgit v1.2.3-59-g8ed1b