Bug 291386 – sys-fs/mdadm version bump to 3.1 (or at least 3.0.3)

• Status: RESOLVED FIXED
• Product: Gentoo Linux

[Description Michael Evans 2009-10-31 23:23:21 UTC]

mdadm 3.0.2 with kernel 2.6.31-gentoo-r4 fails to grow a raid 5 array.
mdadm 3.1 with kernel 2.6.31-gentoo-r4 will grow raid 5 arrays and adds the capability to re-stripe raid5 to raid6.

Reproducible: Always

Steps to Reproduce:
#!/bin/bash
# -e

function create_block {
	# SizeMB , Name
	dd if=/dev/zero bs=1024k count="$1" of="$2"
}

function setup_blockdevs {
	# count, Name
	ii_setup_bd=0;
	while [[ $ii_setup_bd -lt $1 ]]
		do
		cp "$2" "$2"."$ii_setup_bd"
		devs[$ii_setup_bd]=`losetup -f --show "$2"."$ii_setup_bd"`
		ii_setup_bd=$(($ii_setup_bd + 1))
		done
}

function print_list {
	# list
	while [[ -n "$1" ]]
		do
		echo $1
		shift
		done
}

function delete_blockdevs {
	# list, shifted out
	while [[ -n "$1" ]]
		do
		#echo rm $1
		losetup -d $1
		shift
		done
}

create_block 33 test_devs
setup_blockdevs 6 test_devs

## Create array, raid 0
mdadm --create /dev/md90 -e 1.2 -c 64 --verbose --level=5 --raid-devices=3 ${devs[0]} ${devs[1]} ${devs[2]}
uuid=`mdadm --detail /dev/md90 | awk '/UUID/ {print $3}'`
echo "$uuid"
#sleep 5

if [[ -z "$uuid" ]] ; then exit ; fi

## Create filesystem and test data
mkfs.ext4 /dev/md90
mkdir "/tmp/test$uuid"
mount /dev/md90 "/tmp/test$uuid"
pushd "/tmp/test$uuid"
dd if=/dev/urandom of="random-data" bs=1024k count=10
popd
umount "/tmp/test$uuid"

## test
mount /dev/md90 "/tmp/test$uuid"
pushd "/tmp/test$uuid"
md5sum -b random-data > random-data.md5
md5sum -c *.md5
popd
umount "/tmp/test$uuid"

## grow
mdadm --add /dev/md90 ${devs[3]}
mdadm --detail /dev/md90
echo "Trying to grow RAID5 by one device"
mdadm --grow /dev/md90 --level=5 -n4
mdadm --detail /dev/md90
sleep 5

## test
mount /dev/md90 "/tmp/test$uuid"
pushd "/tmp/test$uuid"
md5sum -b random-data > random-data.md5
md5sum -c *.md5
popd
umount "/tmp/test$uuid"

## grow
mdadm --add /dev/md90 ${devs[4]}
mdadm --detail /dev/md90
echo "Trying to grow RAID5 by one device to RAID6"
mdadm --grow /dev/md90 --level=6 -n5
mdadm --add /dev/md90 ${devs[5]}
mdadm --detail /dev/md90
echo "Trying to grow RAID6 by one device, or RAID5 by two to RAID6 (or if that returns failure, just raid 5)"
mdadm --grow /dev/md90 --level=6 -n6 || mdadm --grow /dev/md90 --level=5 -n6
mdadm --detail /dev/md90
sleep 5

## test
mount /dev/md90 "/tmp/test$uuid"
pushd "/tmp/test$uuid"
md5sum -b random-data > random-data.md5
md5sum -c *.md5
popd
umount "/tmp/test$uuid"

sleep 5
mdadm --stop /dev/md90
delete_blockdevs ${devs[@]}
unset uuid
unset devs
unset ii_setup_bd
rm test_devs*

exit



See the linked URL ( http://www.kernel.org/pub/linux/utils/raid/mdadm/ ) for upstream versions.

[Comment 1 SpanKY 2009-11-01 19:59:49 UTC]

it isnt really "mdadm-3.0.2 fails to grow a raid 5 array" as it never supported it in the first place

added both 3.1 and 3.0.3 to the tree

[Comment 2 Michael Evans 2009-11-02 20:15:33 UTC]

I remember mdadm was able to grow raid5 arrays before; however it was not previously able to complete a raid6 takeover of a raid5 array.