Package: mdadm Version: 3.4-4 Severity: important mdadm seems to have a limit of 27 block devices for a RAID array.
Is this limit documented anywhere? Is it configurable? I tried the solution suggested here, but it didn't help: http://dev.bizo.com/2012/07/mdadm-device-or-resource-busy.html # truncate -s 64M fs.{00..31} # # ls fs.00 fs.03 fs.06 fs.09 fs.12 fs.15 fs.18 fs.21 fs.24 fs.27 fs.30 fs.01 fs.04 fs.07 fs.10 fs.13 fs.16 fs.19 fs.22 fs.25 fs.28 fs.31 fs.02 fs.05 fs.08 fs.11 fs.14 fs.17 fs.20 fs.23 fs.26 fs.29 # # for x in fs.* ; do losetup --show -f $x ; done /dev/loop0 /dev/loop1 /dev/loop2 /dev/loop3 /dev/loop4 /dev/loop5 /dev/loop6 /dev/loop7 /dev/loop8 /dev/loop9 /dev/loop10 /dev/loop11 /dev/loop12 /dev/loop13 /dev/loop14 /dev/loop15 /dev/loop16 /dev/loop17 /dev/loop18 /dev/loop19 /dev/loop20 /dev/loop21 /dev/loop22 /dev/loop23 /dev/loop24 /dev/loop25 /dev/loop26 /dev/loop27 /dev/loop28 /dev/loop29 /dev/loop30 /dev/loop31 # # # *** RAID FAILURE *** : # # mdadm --build /dev/md/md-test --level=linear --raid-devices=28 /dev/loop{0..27} mdadm: ADD_NEW_DISK failed for /dev/loop27: Device or resource busy # # # *** RAID SUCCESS *** : # # mdadm --build /dev/md/md-test --level=linear --raid-devices=27 /dev/loop{0..26} mdadm: array /dev/md/md-test built and started. # # mdadm --detail /dev/md/md-test /dev/md/md-test: Version : Creation Time : Wed Feb 22 07:48:57 2017 Raid Level : linear Array Size : 1769472 (1728.00 MiB 1811.94 MB) Raid Devices : 27 Total Devices : 27 State : clean Active Devices : 27 Working Devices : 27 Failed Devices : 0 Spare Devices : 0 Rounding : 64K Number Major Minor RaidDevice State 0 7 0 0 active sync /dev/loop0 1 7 1 1 active sync /dev/loop1 2 7 2 2 active sync /dev/loop2 3 7 3 3 active sync /dev/loop3 4 7 4 4 active sync /dev/loop4 5 7 5 5 active sync /dev/loop5 6 7 6 6 active sync /dev/loop6 7 7 7 7 active sync /dev/loop7 8 7 8 8 active sync /dev/loop8 9 7 9 9 active sync /dev/loop9 10 7 10 10 active sync /dev/loop10 11 7 11 11 active sync /dev/loop11 12 7 12 12 active sync /dev/loop12 13 7 13 13 active sync /dev/loop13 14 7 14 14 active sync /dev/loop14 15 7 15 15 active sync /dev/loop15 16 7 16 16 active sync /dev/loop16 17 7 17 17 active sync /dev/loop17 18 7 18 18 active sync /dev/loop18 19 7 19 19 active sync /dev/loop19 20 7 20 20 active sync /dev/loop20 21 7 21 21 active sync /dev/loop21 22 7 22 22 active sync /dev/loop22 23 7 23 23 active sync /dev/loop23 24 7 24 24 active sync /dev/loop24 25 7 25 25 active sync /dev/loop25 26 7 26 26 active sync /dev/loop26 # # mdadm --stop /dev/md/md-test mdadm: stopped /dev/md/md-test # # losetup -d /dev/loop{0..31} # -- System Information: Debian Release: 9.0 APT prefers testing APT policy: (990, 'testing'), (500, 'stable-updates'), (500, 'unstable'), (500, 'stable') Architecture: amd64 (x86_64) Kernel: Linux 4.6.0-1-amd64 (SMP w/4 CPU cores) Locale: LANG=en_CA.utf8, LC_CTYPE=en_CA.utf8 (charmap=UTF-8) Shell: /bin/sh linked to /bin/dash Init: systemd (via /run/systemd/system) Versions of packages mdadm depends on: ii debconf [debconf-2.0] 1.5.60 ii libc6 2.24-9 ii lsb-base 9.20161125 ii udev 232-15 Versions of packages mdadm recommends: ii exim4-daemon-light [mail-transport-agent] 4.88-5 ii kmod 23-2 mdadm suggests no packages.
