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 <pool> draid[1,2,3] <vdevs...>

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 <pool> \
        draid[<parity>][:<data>d][:<children>c][:<spares>s] \
        <vdevs...>

    - draid[parity]       - Parity level (default 1)
    - draid[:<data>d]     - Data devices per group (default 8)
    - draid[:<children>c] - Expected number of child vdevs
    - draid[:<spares>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 <value>            - dRAID data drives per group
    -S <value>            - dRAID distributed hot spares
    -R <value>            - 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 <he.huang@intel.com>
Co-authored-by: Mark Maybee <mmaybee@cray.com>
Co-authored-by: Don Brady <don.brady@delphix.com>
Co-authored-by: Matthew Ahrens <mahrens@delphix.com>
Co-authored-by: Brian Behlendorf <behlendorf1@llnl.gov>
Reviewed-by: Mark Maybee <mmaybee@cray.com>
Reviewed-by: Matt Ahrens <matt@delphix.com>
Reviewed-by: Tony Hutter <hutter2@llnl.gov>
Signed-off-by: Brian Behlendorf <behlendorf1@llnl.gov>
Closes #10102 

1 files changed, 17 insertions, 4 deletions

diff --git a/tests/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_missing_001_pos.ksh b/tests/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_missing_001_pos.ksh
index 78e9bbf689d0..3b5167ff0374 100755
--- a/tests/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_missing_001_pos.ksh
+++ b/tests/zfs-tests/tests/functional/cli_root/zpool_import/zpool_import_missing_001_pos.ksh
@@ -57,8 +57,8 @@
 #	   Using the various combinations.
 #		- Regular import
 #		- Alternate Root Specified
-#	   It should be succeed with single d/m device upon 'raidz' & 'mirror',
-#	   but failed against 'regular' or more d/m devices.
+#	   It should succeed with single d/m device upon 'raidz', 'mirror',
+#	   'draid' but failed against 'regular' or more d/m devices.
 #	6. If import succeed, verify following is true:
 #		- The pool shows up under 'zpool list'.
 #		- The pool's health should be DEGRADED.
@@ -67,7 +67,16 @@
 
 verify_runnable "global"
 
-set -A vdevs "" "mirror" "raidz"
+# Randomly test a subset of combinations to speed up the test.
+(( rc=RANDOM % 3 ))
+if [[ $rc == 0 ]] ; then
+	set -A vdevs "" "mirror" "raidz"
+elif [[ $rc == 1 ]] ; then
+	set -A vdevs "" "mirror" "draid"
+else
+	set -A vdevs "" "raidz" "draid"
+fi
+
 set -A options "" "-R $ALTER_ROOT"
 
 function cleanup
@@ -89,7 +98,8 @@ function recreate_files
 	log_must rm -rf $DEVICE_DIR/*
 	typeset i=0
 	while (( i < $MAX_NUM )); do
-		log_must mkfile $FILE_SIZE ${DEVICE_DIR}/${DEVICE_FILE}$i
+		log_must rm -f ${DEVICE_DIR}/${DEVICE_FILE}$i
+		log_must truncate -s $FILE_SIZE ${DEVICE_DIR}/${DEVICE_FILE}$i
 		((i += 1))
 	done
 }
@@ -157,6 +167,9 @@ while (( i < ${#vdevs[*]} )); do
 				'raidz')  (( count > 1 )) && \
 						action=log_mustnot
 					;;
+				'draid')  (( count > 1 )) && \
+						action=log_mustnot
+					;;
 				'')  action=log_mustnot
 					;;
 			esac