At a stable hardened Gentoo Linux server (kernel 5.1, same for 4.19) I do have
2 BTRFS file systems, ./img1 and ./img2. I do write data to either of it for
about 1 month, then I do switch the symlink ./img from ./img1 to ./img2 or vice
versa.
# grep img /etc/fstab
/dev/vg0/lvol0 /home/tinderbox/img1 btrfs auto,noatime
0 0
/dev/vg0/lvol1 /home/tinderbox/img2 btrfs auto,noatime
0 0
# vgs
VG #PV #LV #SN Attr VSize VFree
vg0 2 3 0 wz--n- <3.58t 0
# pvs
PV VG Fmt Attr PSize PFree
/dev/sda5 vg0 lvm2 a-- <1.76t 0
/dev/sdb1 vg0 lvm2 a-- <1.82t 0
# lvs
LV VG Attr LSize Pool Origin Data% Meta% Move Log
Cpy%Sync Convert
lvol0 vg0 -wi-ao---- 1.56t
lvol1 vg0 -wi-ao---- 1.56t
lvol2 vg0 -wi-ao---- 461.02g
FWIW I do prefer "mkfs" over "rm -rf" due to the large size of the FS (1.6 TB).
But I run regularly into this problem:
# mount /home/tinderbox/img1
# umount /home/tinderbox/img1
# btrfs check -p /dev/vg0/lvol0
Opening filesystem to check...
ERROR: cannot open device '/dev/vg0/lvol0': Device or resource busy
ERROR: cannot open file system
# mkfs.btrfs -f /dev/mapper/vg0-lvol0
btrfs-progs v5.1
See http://btrfs.wiki.kernel.org for more information.
ERROR: unable to open /dev/mapper/vg0-lvol0: Device or resource busy
A reboot helps, but after 1 or 2 days or so I run into the same situation even
if I do not write files to it. I rebooted the system 24 hours ago and wrote not
into ./img1, but do still suffer from the situation above. Neither lsof nor
fuser show anything suspicious althought I do not understand the fuser output
after the unmount:
# mount /home/tinderbox/img1
# df -h /home/tinderbox/img1
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg0-lvol0 1.6T 1.4T 166G 90% /home/tinderbox/img1
# fuser -mv /home/tinderbox/img1
USER PID ACCESS COMMAND
/home/tinderbox/img1:
root kernel mount /home/tinderbox/img1
# umount /home/tinderbox/img1
# fuser -mv /home/tinderbox/img1
USER PID ACCESS COMMAND
/home/tinderbox/img1:
root kernel mount /
root 1 .rce. init
root 2 .rc.. kthreadd
root 3 .rc.. rcu_gp
root 4 .rc.. rcu_par_gp
root 6 .rc.. kworker/0:0H-kbl
root 8 .rc.. mm_percpu_wq
root 9 .rc.. ksoftirqd/0
root 10 .rc.. rcu_sched
root 11 .rc.. migration/0
root 12 .rc.. cpuhp/0
root 13 .rc.. cpuhp/1
root 14 .rc.. migration/1
root 15 .rc.. ksoftirqd/1
root 17 .rc.. kworker/1:0H-kbl
root 18 .rc.. cpuhp/2
root 19 .rc.. migration/2
root 20 .rc.. ksoftirqd/2
root 22 .rc.. kworker/2:0H-kbl
root 23 .rc.. cpuhp/3
root 24 .rc.. migration/3
root 25 .rc.. ksoftirqd/3
root 27 .rc.. kworker/3:0H-kbl
root 28 .rc.. cpuhp/4
root 29 .rc.. migration/4
root 30 .rc.. ksoftirqd/4
root 32 .rc.. kworker/4:0H-kbl
root 33 .rc.. cpuhp/5
root 34 .rc.. migration/5
root 35 .rc.. ksoftirqd/5
root 37 .rc.. kworker/5:0H-kbl
root 38 .rc.. cpuhp/6
root 39 .rc.. migration/6
root 40 .rc.. ksoftirqd/6
root 42 .rc.. kworker/6:0H-kbl
root 43 .rc.. cpuhp/7
root 44 .rc.. migration/7
root 45 .rc.. ksoftirqd/7
root 47 .rc.. kworker/7:0H-kbl
root 48 .rc.. cpuhp/8
root 49 .rc.. migration/8
root 50 .rc.. ksoftirqd/8
root 52 .rc.. kworker/8:0H-kbl
root 53 .rc.. cpuhp/9
root 54 .rc.. migration/9
root 55 .rc.. ksoftirqd/9
root 57 .rc.. kworker/9:0H-kbl
root 58 .rc.. cpuhp/10
root 59 .rc.. migration/10
root 60 .rc.. ksoftirqd/10
root 62 .rc.. kworker/10:0H-kb
root 63 .rc.. cpuhp/11
root 64 .rc.. migration/11
root 65 .rc.. ksoftirqd/11
root 67 .rc.. kworker/11:0H-kb
root 69 .rc.. netns
root 72 .rc.. oom_reaper
root 73 .rc.. writeback
root 74 .rc.. kcompactd0
root 75 .rc.. khugepaged
root 76 .rc.. crypto
root 77 .rc.. kintegrityd
root 78 .rc.. kblockd
root 81 .rc.. edac-poller
root 87 .rc.. kswapd0
root 114 .rc.. kthrotld
root 115 .rc.. irq/25-aerdrv
root 116 .rc.. irq/27-aerdrv
root 121 .rc.. acpi_thermal_pm
root 122 .rc.. scsi_eh_0
root 123 .rc.. scsi_tmf_0
root 124 .rc.. scsi_eh_1
root 125 .rc.. scsi_tmf_1
root 126 .rc.. scsi_eh_2
root 127 .rc.. scsi_tmf_2
root 128 .rc.. scsi_eh_3
root 129 .rc.. scsi_tmf_3
root 130 .rc.. scsi_eh_4
root 131 .rc.. scsi_tmf_4
root 132 .rc.. scsi_eh_5
root 133 .rc.. scsi_tmf_5
root 140 .rc.. ipv6_addrconf
root 168 .rc.. jbd2/sda4-8
root 169 .rc.. ext4-rsv-conver
root 173 .rc.. kworker/6:1H-eve
root 613 .rce. udevd
root 738 .rc.. kworker/9:1H-eve
root 742 .rc.. kworker/8:1H-kbl
root 758 .rc.. kworker/10:1H-ev
root 768 .rc.. kdmflush
root 770 .rc.. kdmflush
root 771 .rc.. kdmflush
root 858 .rc.. kworker/3:1-even
root 885 .rc.. kdmflush
root 886 .rc.. kcryptd_io/254:
root 887 .rc.. kcryptd/254:3
root 888 .rc.. dmcrypt_write/2
root 897 .rc.. kworker/0:1H-kbl
root 932 .rce. lvmetad
root 1011 .rc.. kworker/5:1H-eve
root 1042 .rc.. kworker/u24:9-bt
root 1046 .rc.. kworker/4:1H-eve
root 1047 .rc.. kworker/2:1H-eve
root 1110 frce. watch.sh
root 1111 frce. watch.sh
root 1112 frce. watch.sh
root 1113 frce. watch.sh
root 1114 frce. watch.sh
root 1115 .rce. tail
root 1116 .rce. grep
root 1117 .rce. watch.sh
root 1118 frce. tail
root 1119 frce. tail
root 1120 .rce. grep
root 1121 .rce. grep
root 1122 .rce. watch.sh
root 1123 .rce. tail
root 1124 .rce. grep
root 1125 .rce. watch.sh
root 1126 .rce. watch.sh
root 1127 frce. tail
root 1128 .rce. grep
root 1129 .rce. watch.sh
root 1154 .rc.. btrfs-worker
root 1155 .rc.. btrfs-worker-hi
root 1156 .rc.. btrfs-delalloc
root 1157 .rc.. btrfs-flush_del
root 1158 .rc.. btrfs-cache
root 1159 .rc.. btrfs-submit
root 1160 .rc.. btrfs-fixup
root 1161 .rc.. btrfs-endio
root 1162 .rc.. btrfs-endio-met
root 1163 .rc.. btrfs-endio-met
root 1164 .rc.. btrfs-endio-rai
root 1165 .rc.. btrfs-endio-rep
root 1166 .rc.. btrfs-rmw
root 1167 .rc.. btrfs-endio-wri
root 1168 .rc.. btrfs-freespace
root 1169 .rc.. btrfs-delayed-m
root 1170 .rc.. btrfs-readahead
root 1171 .rc.. btrfs-qgroup-re
root 1172 .rc.. btrfs-extent-re
root 1173 .rc.. btrfs-cleaner
root 1174 .rc.. btrfs-transacti
root 1175 .rc.. btrfs-worker
root 1176 .rc.. btrfs-worker-hi
root 1178 .rc.. btrfs-delalloc
root 1179 .rc.. btrfs-flush_del
root 1180 .rc.. btrfs-cache
root 1181 .rc.. btrfs-submit
root 1182 .rc.. btrfs-fixup
root 1183 .rc.. btrfs-endio
root 1184 .rc.. btrfs-endio-met
root 1185 .rc.. btrfs-endio-met
root 1186 .rc.. btrfs-endio-rai
root 1187 .rc.. btrfs-endio-rep
root 1188 .rc.. btrfs-rmw
root 1189 .rc.. btrfs-endio-wri
root 1190 .rc.. btrfs-freespace
root 1191 .rc.. btrfs-delayed-m
root 1192 .rc.. btrfs-readahead
root 1193 .rc.. btrfs-qgroup-re
root 1194 .rc.. btrfs-extent-re
root 1195 .rc.. btrfs-cleaner
root 1196 .rc.. btrfs-transacti
root 1198 .rc.. btrfs-worker
root 1199 .rc.. btrfs-worker-hi
root 1200 .rc.. btrfs-delalloc
root 1201 .rc.. btrfs-flush_del
root 1202 .rc.. btrfs-cache
root 1203 .rc.. btrfs-submit
root 1204 .rc.. btrfs-fixup
root 1205 .rc.. btrfs-endio
root 1206 .rc.. btrfs-endio-met
root 1207 .rc.. btrfs-endio-met
root 1208 .rc.. btrfs-endio-rai
root 1209 .rc.. btrfs-endio-rep
root 1210 .rc.. btrfs-rmw
root 1211 .rc.. btrfs-endio-wri
root 1212 .rc.. btrfs-freespace
root 1213 .rc.. btrfs-delayed-m
root 1214 .rc.. btrfs-readahead
root 1215 .rc.. btrfs-qgroup-re
root 1216 .rc.. btrfs-extent-re
root 1217 .rc.. btrfs-cleaner
root 1218 .rc.. btrfs-transacti
root 1515 .rc.. kworker/3:1H-kbl
root 1590 .rce. syslog-ng
root 1591 Fr.e. syslog-ng
root 1625 .rce. acpid
at 1653 .rce. atd
root 1743 .rce. timer_entropyd
root 2024 .rc.. kworker/1:1H-kbl
dnsmasq 2064 .rce. dnsmasq
root 2124 .rce. crond
root 2153 .rce. crond
root 2156 .rce. haveged
root 2167 frce. catch_load.sh
root 2228 .rce. ntpd
root 2258 .rce. rngd
root 2293 .rce. smartd
root 2325 .rce. sshd
root 2430 frce. restart_service
root 2431 frce. restart_service
root 2432 frce. restart_service
root 2507 .rce. agetty
root 2508 .rce. agetty
root 2509 .rce. agetty
root 2510 .rce. agetty
root 2511 .rce. agetty
root 2512 .rce. agetty
root 2666 .rc.. kworker/7:1H-kbl
root 2804 .rc.. kworker/11:1H-kb
root 2912 Frce. sudo
root 2915 Frce. chr.sh
root 2973 F.... su
root 3022 Frce. sudo
root 3025 Frce. chr.sh
root 3047 F.... bash
root 3071 F.... su
root 3074 Frce. sudo
root 3077 Frce. chr.sh
root 3124 F.... su
root 3127 Frce. sudo
root 3130 Frce. chr.sh
root 3164 Frce. sudo
root 3167 Frce. chr.sh
root 3183 F.... su
root 3192 F.... bash
root 3236 F.... su
root 3238 Frce. sudo
root 3241 Frce. chr.sh
root 3261 F.... bash
root 3286 F.... su
root 3289 Frce. sudo
root 3292 Frce. chr.sh
tinderbox 3315 frce. logcheck.sh
root 3323 F.... bash
root 3336 F.... su
root 3339 F.... bash
root 3373 F.... bash
root 3387 F.... bash
root 3959 .rc.. kworker/4:0
root 4307 Frce. sudo
root 4310 Frce. chr.sh
root 4905 F.... su
root 4906 F.... bash
root 4994 .rc.. kworker/u25:0-bt
root 5069 .rc.. kworker/9:0-even
tor 6675 Frce. tor
root 7714 .rc.. kworker/10:1-mm_
root 7802 .rc.. kworker/0:0-even
root 8348 .rc.. kworker/11:1-eve
root 8375 .rc.. kworker/11:3-eve
root 8879 .rc.. kworker/u24:2-bt
root 8905 .rc.. kworker/3:0-even
root 9188 .rc.. kworker/5:1-mm_p
root 9403 .rc.. kworker/2:2-cgro
root 9851 .rc.. kworker/11:2-rcu
root 10023 .rc.. kworker/7:2-even
root 11092 .rc.. kworker/u24:4-bt
root 11103 Frce. sudo
root 11108 Frce. chr.sh
root 11283 .rc.. kworker/10:2-eve
root 11483 F.... su
root 11485 F.... bash
root 11730 .rce. sshd
tfoerste 11805 .rce. sshd
tfoerste 11829 .rce. bash
root 11898 .rc.. kworker/4:1-cgro
root 11941 .rc.. kworker/u24:7-bt
root 11960 .rc.. kworker/u24:8-bt
root 12026 .rc.. kworker/6:2-even
root 12079 .rce. sudo
root 12081 .rce. su
root 12083 .rce. bash
root 12337 .rc.. kworker/u25:1-bt
root 13106 .rc.. kworker/5:0
root 13568 .rc.. kworker/u24:11-b
root 13991 .rc.. kworker/3:3-mm_p
root 15022 .rc.. kworker/5:2-even
root 15087 .rc.. kworker/2:0-mm_p
root 15283 .rc.. kworker/2:1-cgro
root 15939 .rc.. kworker/10:0-eve
root 16963 .rce. sleep
root 17018 .rc.. kworker/7:3-mm_p
root 17139 .rc.. kworker/4:3-cgro
root 17147 .rce. sleep
root 17177 .rc.. kworker/0:1-cgro
root 17423 .rc.. kworker/8:0-mm_p
root 17644 .rc.. kworker/0:2-cgro
root 17802 .rce. sleep
root 18468 .rc.. kworker/10:3-cgr
root 18869 .rce. sleep
tinderbox 19031 .rce. sleep
root 19062 .rc.. kworker/6:0-mm_p
root 20813 .rc.. kworker/7:1-rcu_
root 20932 .rc.. kworker/u24:0-bt
root 21045 .rc.. kworker/11:0-mm_
root 21178 .rc.. kworker/8:2-cgro
root 21441 .rc.. kworker/9:1-cgro
root 22857 .rc.. kworker/1:3-even
root 23358 .rc.. kworker/u24:1-ev
root 23359 .rc.. kworker/u24:3-bt
root 23821 .rc.. kworker/1:2-rcu_
root 23854 .rc.. kworker/8:1-even
root 26148 .rc.. kworker/7:0-even
root 26178 .rc.. kworker/5:4-even
root 28450 .rc.. kworker/3:2-even
root 28571 .rc.. kworker/9:3-even
root 28640 .rc.. kworker/6:1
tor 29097 Frce. tor
root 31539 .rc.. kworker/0:3-even
root 31954 .rc.. kworker/8:3
root 32727 .rc.. kworker/1:1+even
--
Toralf
PGP C4EACDDE 0076E94E
