I cannot shrink btrfs filesystem although there is still data and metadata space left :
$ sudo btrfs filesystem resize -11G /home;echo $?
Resize '/home' of '-11G'
ERROR: unable to resize '/home': No space left on device
1
Here are some btrfs filesystem info about /home :
$ sudo btrfs filesystem df /home | column -t
Data, single: total=92.01GiB, used=80.68GiB
System, DUP: total=8.00MiB, used=16.00KiB
System, single: total=4.00MiB, used=0.00B
Metadata, DUP: total=1.00GiB, used=631.41MiB
Metadata, single: total=8.00MiB, used=0.00B
GlobalReserve, single: total=224.00MiB, used=0.00B
$ sudo btrfs filesystem show /home
Label: none uuid: c7ee56a8-ef45-46c8-86d1-13879201a1e7
Total devices 1 FS bytes used 81.30GiB
devid 1 size 100.00GiB used 94.04GiB path /dev/mapper/home_VG-home
$ sudo btrfs filesystem usage -T /home
Overall:
Device size: 100.00GiB
Device allocated: 94.04GiB
Device unallocated: 5.96GiB
Device missing: 0.00B
Used: 81.91GiB
Free (estimated): 17.29GiB (min: 14.31GiB)
Data ratio: 1.00
Metadata ratio: 1.99
Global reserve: 224.00MiB (used: 0.00B)
Data Metadata Metadata System System
Id Path single single DUP single DUP Unallocated
-- --------- -------- -------- --------- ------- -------- -----------
1 /dev/dm-0 92.01GiB 8.00MiB 2.00GiB 4.00MiB 16.00MiB 5.96GiB
-- --------- -------- -------- --------- ------- -------- -----------
Total 92.01GiB 8.00MiB 1.00GiB 4.00MiB 8.00MiB 5.96GiB
Used 80.68GiB 0.00B 631.41MiB 0.00B 16.00KiB
and here the output of dmesg :
$ dmesg | tail -11
[44202.411949] BTRFS info (device dm-0): new size for /dev/dm-0 is 97706311680
[44202.412156] BTRFS info (device dm-0): relocating block group 120288444416 flags 1
[44208.119721] BTRFS info (device dm-0): relocating block group 119214702592 flags 1
[44211.611669] BTRFS info (device dm-0): relocating block group 118140960768 flags 1
[44212.495603] BTRFS info (device dm-0): relocating block group 117067218944 flags 1
[44213.006830] BTRFS info (device dm-0): relocating block group 95592382464 flags 1
[44216.613870] BTRFS info (device dm-0): relocating block group 120288444416 flags 1
[44222.780073] BTRFS info (device dm-0): relocating block group 119214702592 flags 1
[44225.843279] BTRFS info (device dm-0): relocating block group 118140960768 flags 1
[44226.575236] BTRFS info (device dm-0): relocating block group 117067218944 flags 1
[44226.930918] BTRFS info (device dm-0): relocating block group 95592382464 flags 1
EDIT1 : The btrfs balance failed :
$ sudo btrfs balance start /home
ERROR: error during balancing '/home': No space left on device
There may be more info in syslog - try dmesg | tail
There nothing in dmesg | tail about it.
EDIT2 : I had to do the following to be able to start the btrfs balance :
$ sudo btrfs balance start -musage=0 -dusage=0 -v /home
Dumping filters: flags 0x7, state 0x0, force is off
METADATA (flags 0x2): balancing, usage=0
SYSTEM (flags 0x2): balancing, usage=0
DATA (flags 0x2): balancing, usage=0
Done, had to relocate 0 out of 95 chunks
EDIT3 : The btrfs balance has ran for 68 minutes and then failed :
$ time sudo btrfs balance start -v /home
Dumping filters: flags 0x7, state 0x0, force is off
DATA (flags 0x0): balancing
METADATA (flags 0x0): balancing
SYSTEM (flags 0x0): balancing
ERROR: error during balancing '/home': Input/output error
There may be more info in syslog - try dmesg | tail
real 68m10.221s
user 0m0.008s
sys 4m20.236s
Here is what dmesg shows :
[74421.794756] ata2.00: exception Emask 0x0 SAct 0xc00 SErr 0x0 action 0x0
[74421.794766] ata2.00: irq_stat 0x40000001
[74421.794773] ata2.00: failed command: READ FPDMA QUEUED
[74421.794783] ata2.00: cmd 60/08:50:48:96:f8/00:00:25:00:00/40 tag 10 ncq 4096 in
[74421.794783] res 41/40:08:48:96:f8/00:00:25:00:00/40 Emask 0x409 (media error) <F>
[74421.794788] ata2.00: status: { DRDY ERR }
[74421.794791] ata2.00: error: { UNC }
[74421.794794] ata2.00: failed command: READ FPDMA QUEUED
[74421.794802] ata2.00: cmd 60/10:58:40:af:ed/00:00:20:00:00/40 tag 11 ncq 8192 in
[74421.794802] res 41/40:58:48:96:f8/00:00:25:00:00/40 Emask 0x9 (media error)
[74421.794806] ata2.00: status: { DRDY ERR }
[74421.794809] ata2.00: error: { UNC }
[74421.798253] ata2.00: configured for UDMA/100
[74421.798303] sd 1:0:0:0: [sdb] tag#10 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[74421.798315] sd 1:0:0:0: [sdb] tag#10 Sense Key : Medium Error [current] [descriptor]
[74421.798326] sd 1:0:0:0: [sdb] tag#10 Add. Sense: Unrecovered read error - auto reallocate failed
[74421.798337] sd 1:0:0:0: [sdb] tag#10 CDB: Read(10) 28 00 25 f8 96 48 00 00 08 00
[74421.798344] blk_update_request: I/O error, dev sdb, sector 637048392
[74421.798366] BTRFS error (device dm-0): bdev /dev/dm-0 errs: wr 38, rd 451, flush 0, corrupt 0, gen 0
[74421.798425] sd 1:0:0:0: [sdb] tag#11 FAILED Result: hostbyte=DID_OK driverbyte=DRIVER_SENSE
[74421.798435] sd 1:0:0:0: [sdb] tag#11 Sense Key : Medium Error [current] [descriptor]
[74421.798444] sd 1:0:0:0: [sdb] tag#11 Add. Sense: Unrecovered read error - auto reallocate failed
[74421.798453] sd 1:0:0:0: [sdb] tag#11 CDB: Read(10) 28 00 20 ed af 40 00 00 10 00
[74421.798459] blk_update_request: I/O error, dev sdb, sector 552447808
[74421.798523] ata2: EH complete
EDIT 4 : I'm actually using /dev/sdb :
$ sudo smartctl -a /dev/sdb
smartctl 6.2 2013-07-26 r3841 [x86_64-linux-4.4.0-143-generic] (local build)
Copyright (C) 2002-13, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Toshiba 2.5" HDD MQ01ABD...
Device Model: TOSHIBA MQ01ABD100
Serial Number: 84EWT2U5T
LU WWN Device Id: 5 000039 5b1f852cb
Firmware Version: AX1P4M
User Capacity: 1 000 204 886 016 bytes [1,00 TB]
Sector Size: 512 bytes logical/physical
Rotation Rate: 5400 rpm
Device is: In smartctl database [for details use: -P show]
ATA Version is: ATA8-ACS (minor revision not indicated)
SATA Version is: SATA 2.6, 3.0 Gb/s (current: 3.0 Gb/s)
Local Time is: Mon Apr 1 23:34:41 2019 CEST
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
General SMART Values:
Offline data collection status: (0x82) Offline data collection activity
was completed without error.
Auto Offline Data Collection: Enabled.
Self-test execution status: ( 0) The previous self-test routine completed
without error or no self-test has ever
been run.
Total time to complete Offline
data collection: ( 120) seconds.
Offline data collection
capabilities: (0x5b) SMART execute Offline immediate.
Auto Offline data collection on/off support.
Suspend Offline collection upon new
command.
Offline surface scan supported.
Self-test supported.
No Conveyance Self-test supported.
Selective Self-test supported.
SMART capabilities: (0x0003) Saves SMART data before entering
power-saving mode.
Supports SMART auto save timer.
Error logging capability: (0x01) Error logging supported.
General Purpose Logging supported.
Short self-test routine
recommended polling time: ( 2) minutes.
Extended self-test routine
recommended polling time: ( 243) minutes.
SCT capabilities: (0x003d) SCT Status supported.
SCT Error Recovery Control supported.
SCT Feature Control supported.
SCT Data Table supported.
SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAG VALUE WORST THRESH TYPE UPDATED WHEN_FAILED RAW_VALUE
1 Raw_Read_Error_Rate 0x000b 100 100 050 Pre-fail Always - 0
2 Throughput_Performance 0x0005 100 100 050 Pre-fail Offline - 0
3 Spin_Up_Time 0x0027 100 100 001 Pre-fail Always - 1735
4 Start_Stop_Count 0x0032 100 100 000 Old_age Always - 5639
5 Reallocated_Sector_Ct 0x0033 100 100 050 Pre-fail Always - 0
7 Seek_Error_Rate 0x000b 100 100 050 Pre-fail Always - 0
8 Seek_Time_Performance 0x0005 100 100 050 Pre-fail Offline - 0
9 Power_On_Hours 0x0032 080 080 000 Old_age Always - 8259
10 Spin_Retry_Count 0x0033 212 100 030 Pre-fail Always - 0
12 Power_Cycle_Count 0x0032 100 100 000 Old_age Always - 5623
191 G-Sense_Error_Rate 0x0032 100 100 000 Old_age Always - 563
192 Power-Off_Retract_Count 0x0032 100 100 000 Old_age Always - 203
193 Load_Cycle_Count 0x0032 099 099 000 Old_age Always - 17892
194 Temperature_Celsius 0x0022 100 100 000 Old_age Always - 23 (Min/Max 10/46)
196 Reallocated_Event_Count 0x0032 100 100 000 Old_age Always - 0
197 Current_Pending_Sector 0x0032 100 100 000 Old_age Always - 9200
198 Offline_Uncorrectable 0x0030 001 001 000 Old_age Offline - 255
199 UDMA_CRC_Error_Count 0x0032 200 200 000 Old_age Always - 0
220 Disk_Shift 0x0002 100 100 000 Old_age Always - 0
222 Loaded_Hours 0x0032 080 080 000 Old_age Always - 8117
223 Load_Retry_Count 0x0032 100 100 000 Old_age Always - 0
224 Load_Friction 0x0022 100 100 000 Old_age Always - 0
226 Load-in_Time 0x0026 100 100 000 Old_age Always - 177
240 Head_Flying_Hours 0x0001 100 100 001 Pre-fail Offline - 0
SMART Error Log Version: 1
ATA Error Count: 1029 (device log contains only the most recent five errors)
CR = Command Register [HEX]
FR = Features Register [HEX]
SC = Sector Count Register [HEX]
SN = Sector Number Register [HEX]
CL = Cylinder Low Register [HEX]
CH = Cylinder High Register [HEX]
DH = Device/Head Register [HEX]
DC = Device Command Register [HEX]
ER = Error register [HEX]
ST = Status register [HEX]
Powered_Up_Time is measured from power on, and printed as
DDd+hh:mm:SS.sss where DD=days, hh=hours, mm=minutes,
SS=sec, and sss=millisec. It "wraps" after 49.710 days.
Error 1029 occurred at disk power-on lifetime: 8257 hours (344 days + 1 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 41 50 48 96 f8 40 Error: UNC at LBA = 0x00f89648 = 16291400
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
60 10 58 40 af ed 40 00 03:13:20.172 READ FPDMA QUEUED
60 08 50 48 96 f8 40 00 03:13:16.469 READ FPDMA QUEUED
60 08 48 40 96 f8 40 00 03:13:16.469 READ FPDMA QUEUED
60 08 40 38 96 f8 40 00 03:13:16.469 READ FPDMA QUEUED
60 08 38 30 96 f8 40 00 03:13:16.469 READ FPDMA QUEUED
Error 1028 occurred at disk power-on lifetime: 8257 hours (344 days + 1 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 41 70 48 96 f8 40 Error: UNC at LBA = 0x00f89648 = 16291400
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
60 10 70 78 90 f8 40 00 03:13:11.731 READ FPDMA QUEUED
60 d0 68 a8 89 f8 40 00 03:13:11.731 READ FPDMA QUEUED
61 e0 60 60 aa 0b 40 00 03:13:11.727 WRITE FPDMA QUEUED
61 00 58 60 a2 0b 40 00 03:13:11.723 WRITE FPDMA QUEUED
61 00 50 60 9a 0b 40 00 03:13:11.625 WRITE FPDMA QUEUED
Error 1027 occurred at disk power-on lifetime: 8133 hours (338 days + 21 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 41 c0 f8 bd 51 40 Error: UNC at LBA = 0x0051bdf8 = 5357048
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
60 58 e0 70 fa 40 40 00 00:18:59.971 READ FPDMA QUEUED
61 08 d8 d8 45 2b 40 00 00:18:59.971 WRITE FPDMA QUEUED
61 08 d0 d0 78 6b 40 00 00:18:59.971 WRITE FPDMA QUEUED
61 08 c8 18 42 2b 40 00 00:18:59.971 WRITE FPDMA QUEUED
60 08 c0 f8 bd 51 40 00 00:18:59.971 READ FPDMA QUEUED
Error 1026 occurred at disk power-on lifetime: 8133 hours (338 days + 21 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 41 00 f8 bd 51 40 Error: WP at LBA = 0x0051bdf8 = 5357048
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
61 38 10 28 5f 6b 40 00 00:18:55.963 WRITE FPDMA QUEUED
61 08 08 68 85 6f 40 00 00:18:55.963 WRITE FPDMA QUEUED
60 00 00 f0 bd 51 40 00 00:18:55.946 READ FPDMA QUEUED
60 00 f0 80 75 56 40 00 00:18:55.944 READ FPDMA QUEUED
60 00 e8 80 73 56 40 00 00:18:55.930 READ FPDMA QUEUED
Error 1025 occurred at disk power-on lifetime: 8119 hours (338 days + 7 hours)
When the command that caused the error occurred, the device was active or idle.
After command completion occurred, registers were:
ER ST SC SN CL CH DH
-- -- -- -- -- -- --
40 41 b8 f8 7f 48 40 Error: UNC at LBA = 0x00487ff8 = 4751352
Commands leading to the command that caused the error were:
CR FR SC SN CL CH DH DC Powered_Up_Time Command/Feature_Name
-- -- -- -- -- -- -- -- ---------------- --------------------
60 08 b8 f8 7f 48 40 00 01:10:35.049 READ FPDMA QUEUED
ea 00 00 00 00 00 a0 00 01:10:35.017 FLUSH CACHE EXT
61 08 98 88 4b cb 40 00 01:10:35.017 WRITE FPDMA QUEUED
61 08 70 98 c1 0c 40 00 01:10:35.017 WRITE FPDMA QUEUED
61 08 60 a0 45 cb 40 00 01:10:35.017 WRITE FPDMA QUEUED
SMART Self-test log structure revision number 1
Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error
# 1 Short offline Completed without error 00% 6780 -
# 2 Short offline Completed without error 00% 1 -
SMART Selective self-test log data structure revision number 1
SPAN MIN_LBA MAX_LBA CURRENT_TEST_STATUS
1 0 0 Not_testing
2 0 0 Not_testing
3 0 0 Not_testing
4 0 0 Not_testing
5 0 0 Not_testing
Selective self-test flags (0x0):
After scanning selected spans, do NOT read-scan remainder of disk.
If Selective self-test is pending on power-up, resume after 0 minute delay.
$ echo $?
64
and dmesg reports 2 bad sectors during the last btrfs balance operation :
$ dmesg | grep I/O.error.*sector
[74421.798344] blk_update_request: I/O error, dev sdb, sector 637048392
[74421.798459] blk_update_request: I/O error, dev sdb, sector 552447808
Remapped those the bad sectors :
$ dmesg | grep I/O.error.*sector | awk '/sector/{print "sudo hdparm --yes-i-know-what-i-am-doing --repair-sector "$NF" /dev/sdb"}' | sh -x
+ sudo hdparm --yes-i-know-what-i-am-doing --repair-sector 637048392 /dev/sdb
/dev/sdb:
re-writing sector 637048392: succeeded
+ sudo hdparm --yes-i-know-what-i-am-doing --repair-sector 552447808 /dev/sdb
/dev/sdb:
re-writing sector 552447808: succeeded
EDIT 5 : It seems this command was enough to have more than 11G unallocated :
$ sudo btrfs balance start -musage=0 -dusage=0 -v /home
Dumping filters: flags 0x7, state 0x0, force is off
METADATA (flags 0x2): balancing, usage=0
SYSTEM (flags 0x2): balancing, usage=0
DATA (flags 0x2): balancing, usage=0
Done, had to relocate 0 out of 95 chunks
The btrfs filesystem resize succeeded. (I'm sorry, I've lost the output of the btrfs filesystem resize)
You're requesting the volume to shrink by 11GB, yet you only have about 6GB unallocated.
You can more efficiently use allocated extents by rebalancing the volume. Executing a command similar to
btrfs balance start /homewill start that process, and it may take some time to complete.But I don't know if that will free up enough for a large amount of shrinkage.