Hi again, In message <20160515124534.A42D0100879@xxxxxxxxxxxxx> I wrote: > > I managed to kill a RAID6... ... Trying to follow the overlay method in [1], I run into errors; guess I must be missing something: [1] https://raid.wiki.kernel.org/index.php/Recovering_a_failed_software_RAID#Making_the_harddisks_read-only_using_an_overlay_file # DEVICES="/dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf" # ls /dev/loop* /dev/loop-control /dev/loop0 /dev/loop1 /dev/loop2 /dev/loop3 /dev/loop4 # parallel 'test -e /dev/loop{#} || mknod -m 660 /dev/loop{#} b 7 {#}' ::: $DEVICES # ls /dev/loop* /dev/loop-control /dev/loop0 /dev/loop1 /dev/loop2 /dev/loop3 /dev/loop4 /dev/loop5 /dev/loop6 # parallel truncate -s4000G overlay-{/} ::: $DEVICES # parallel 'size=$(blockdev --getsize {}); loop=$(losetup -f --show -- overlay-{/}); echo 0 $size snapshot {} $loop P 8 | dmsetup create {/}' ::: $DEVICES # OVERLAYS=$(parallel echo /dev/mapper/{/} ::: $DEVICES) # echo $OVERLAYS /dev/mapper/sda /dev/mapper/sdb /dev/mapper/sdc /dev/mapper/sdd /dev/mapper/sde /dev/mapper/sdf # dmsetup status castor2-git_backup: 0 67108864 linear live-base: 0 12582912 linear castor2-f22: 0 67108864 linear castor2-root: 0 134217728 linear castor2-f19: 0 100663296 linear castor2-f19: 100663296 33554432 linear castor2-f21: 0 134217728 linear castor2-f18: 0 67108864 linear castor2-f20: 0 67108864 linear sdf: 0 1953525168 snapshot 16/8388608000 16 sde: 0 1953525168 snapshot 16/8388608000 16 sdd: 0 1953525168 snapshot 16/8388608000 16 live-osimg-min: 0 12582912 snapshot 3688/3688 24 sdc: 0 1953525168 snapshot 16/8388608000 16 live-rw: 0 12582912 snapshot 462664/1048576 1816 sdb: 0 1953525168 snapshot 16/8388608000 16 sda: 0 1953525168 snapshot 16/8388608000 16 # devices="/dev/sda /dev/sdb /dev/sdc /dev/sdd /dev/sde /dev/sdf" # overlay_create() > { > free=$((`stat -c '%a*%S/1024/1024' -f .`)) > echo free ${free}M > overlays="" > overlay_remove > for d in $devices; do > b=$(basename $d) > size_bkl=$(blockdev --getsz $d) # in 512 blocks/sectors > # reserve 1M space for snapshot header > # ext3 max file length is 2TB > truncate -s$((((size_bkl+1)/2)+1024))K $b.ovr || (echo "Do you use ext4?"; return 1) > loop=$(losetup -f --show -- $b.ovr) > # https://www.kernel.org/doc/Documentation/device-mapper/snapshot.txt > dmsetup create $b --table "0 $size_bkl snapshot $d $loop P 8" > echo $d $((size_bkl/2048))M $loop /dev/mapper/$b > overlays="$overlays /dev/mapper/$b" > done > overlays=${overlays# } > } # overlay_remove() > { > for d in $devices; do > b=$(basename $d) > [ -e /dev/mapper/$b ] && dmsetup remove $b && echo /dev/mapper/$b > if [ -e $b.ovr ]; then > echo $b.ovr > l=$(losetup -j $b.ovr | cut -d : -f1) > echo $l > [ -n "$l" ] && losetup -d $(losetup -j $b.ovr | cut -d : -f1) > rm -f $b.ovr &> /dev/null > fi > done > } # echo $OVERLAYS /dev/mapper/sda /dev/mapper/sdb /dev/mapper/sdc /dev/mapper/sdd /dev/mapper/sde /dev/mapper/sdf # mdadm --create --force --verbose /dev/md2 --metadata=1.2 --level=6 --raid-devices=6 --chunk=16 --assume-clean $OVERLAYS mdadm: layout defaults to left-symmetric mdadm: super1.x cannot open /dev/mapper/sda: Device or resource busy mdadm: /dev/mapper/sda is not suitable for this array. mdadm: super1.x cannot open /dev/mapper/sdb: Device or resource busy mdadm: /dev/mapper/sdb is not suitable for this array. mdadm: super1.x cannot open /dev/mapper/sdc: Device or resource busy mdadm: /dev/mapper/sdc is not suitable for this array. mdadm: super1.x cannot open /dev/mapper/sdd: Device or resource busy mdadm: /dev/mapper/sdd is not suitable for this array. mdadm: super1.x cannot open /dev/mapper/sde: Device or resource busy mdadm: /dev/mapper/sde is not suitable for this array. mdadm: super1.x cannot open /dev/mapper/sdf: Device or resource busy mdadm: /dev/mapper/sdf is not suitable for this array. mdadm: create aborted mdadm --assemble --force /dev/md2 $OVERLAYS mdadm: /dev/mapper/sda is busy - skipping mdadm: /dev/mapper/sdb is busy - skipping mdadm: /dev/mapper/sdc is busy - skipping mdadm: /dev/mapper/sdd is busy - skipping mdadm: /dev/mapper/sde is busy - skipping mdadm: /dev/mapper/sdf is busy - skipping # overlay_create free 1843M device-mapper: remove ioctl on sda failed: Device or resource busy Command failed device-mapper: remove ioctl on sdb failed: Device or resource busy Command failed device-mapper: remove ioctl on sdc failed: Device or resource busy Command failed device-mapper: remove ioctl on sdd failed: Device or resource busy Command failed device-mapper: remove ioctl on sde failed: Device or resource busy Command failed device-mapper: remove ioctl on sdf failed: Device or resource busy Command failed device-mapper: create ioctl on sda failed: Device or resource busy Command failed /dev/sda 953869M /dev/loop11 /dev/mapper/sda device-mapper: create ioctl on sdb failed: Device or resource busy Command failed /dev/sdb 953869M /dev/loop12 /dev/mapper/sdb device-mapper: create ioctl on sdc failed: Device or resource busy Command failed /dev/sdc 953869M /dev/loop13 /dev/mapper/sdc device-mapper: create ioctl on sdd failed: Device or resource busy Command failed /dev/sdd 953869M /dev/loop14 /dev/mapper/sdd device-mapper: create ioctl on sde failed: Device or resource busy Command failed /dev/sde 953869M /dev/loop15 /dev/mapper/sde device-mapper: create ioctl on sdf failed: Device or resource busy Command failed /dev/sdf 953869M /dev/loop16 /dev/mapper/sdf What am I doing wrong? Best regards, Wolfgang Denk -- DENX Software Engineering GmbH, Managing Director: Wolfgang Denk HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany Phone: (+49)-8142-66989-10 Fax: (+49)-8142-66989-80 Email: wd@xxxxxxx "Do we define evil as the absence of goodness? It seems only logical that shit happens--we discover this by the process of elimination." -- Larry Wall -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
