From b2255edcc0099e62ad46a3dd9d64537663c6aee3 Mon Sep 17 00:00:00 2001 From: Brian Behlendorf Date: Fri, 13 Nov 2020 13:51:51 -0800 Subject: Distributed Spare (dRAID) Feature This patch adds a new top-level vdev type called dRAID, which stands for Distributed parity RAID. This pool configuration allows all dRAID vdevs to participate when rebuilding to a distributed hot spare device. This can substantially reduce the total time required to restore full parity to pool with a failed device. A dRAID pool can be created using the new top-level `draid` type. Like `raidz`, the desired redundancy is specified after the type: `draid[1,2,3]`. No additional information is required to create the pool and reasonable default values will be chosen based on the number of child vdevs in the dRAID vdev. zpool create draid[1,2,3] Unlike raidz, additional optional dRAID configuration values can be provided as part of the draid type as colon separated values. This allows administrators to fully specify a layout for either performance or capacity reasons. The supported options include: zpool create \ draid[][:d][:c][:s] \ - draid[parity] - Parity level (default 1) - draid[:d] - Data devices per group (default 8) - draid[:c] - Expected number of child vdevs - draid[:s] - Distributed hot spares (default 0) Abbreviated example `zpool status` output for a 68 disk dRAID pool with two distributed spares using special allocation classes. ``` pool: tank state: ONLINE config: NAME STATE READ WRITE CKSUM slag7 ONLINE 0 0 0 draid2:8d:68c:2s-0 ONLINE 0 0 0 L0 ONLINE 0 0 0 L1 ONLINE 0 0 0 ... U25 ONLINE 0 0 0 U26 ONLINE 0 0 0 spare-53 ONLINE 0 0 0 U27 ONLINE 0 0 0 draid2-0-0 ONLINE 0 0 0 U28 ONLINE 0 0 0 U29 ONLINE 0 0 0 ... U42 ONLINE 0 0 0 U43 ONLINE 0 0 0 special mirror-1 ONLINE 0 0 0 L5 ONLINE 0 0 0 U5 ONLINE 0 0 0 mirror-2 ONLINE 0 0 0 L6 ONLINE 0 0 0 U6 ONLINE 0 0 0 spares draid2-0-0 INUSE currently in use draid2-0-1 AVAIL ``` When adding test coverage for the new dRAID vdev type the following options were added to the ztest command. These options are leverages by zloop.sh to test a wide range of dRAID configurations. -K draid|raidz|random - kind of RAID to test -D - dRAID data drives per group -S - dRAID distributed hot spares -R - RAID parity (raidz or dRAID) The zpool_create, zpool_import, redundancy, replacement and fault test groups have all been updated provide test coverage for the dRAID feature. Co-authored-by: Isaac Huang Co-authored-by: Mark Maybee Co-authored-by: Don Brady Co-authored-by: Matthew Ahrens Co-authored-by: Brian Behlendorf Reviewed-by: Mark Maybee Reviewed-by: Matt Ahrens Reviewed-by: Tony Hutter Signed-off-by: Brian Behlendorf Closes #10102 --- include/sys/txg.h | 1 + 1 file changed, 1 insertion(+) (limited to 'include/sys/txg.h') diff --git a/include/sys/txg.h b/include/sys/txg.h index 260a3b43c..22158bd1a 100644 --- a/include/sys/txg.h +++ b/include/sys/txg.h @@ -41,6 +41,7 @@ extern "C" { #define TXG_MASK (TXG_SIZE - 1) /* mask for size */ #define TXG_INITIAL TXG_SIZE /* initial txg */ #define TXG_IDX (txg & TXG_MASK) +#define TXG_UNKNOWN 0 /* Number of txgs worth of frees we defer adding to in-core spacemaps */ #define TXG_DEFER_SIZE 2 -- cgit v1.2.3