telegraf-btrfs-exec

Python script that can be used to capture BTRFS information in telegraf

What does it capture

Currently it captures the following information for all the pools mounted at the time of running

$btrfs device stat

• write_io_errs (per device)
• read_io_errs (per device)
• flush_io_errs (per device)
• corruption_errs (per device)
• generation_errs (per device)

$btrfs filesystem df

• Data (total, used, free)
• System (total, used, free)
• Metadata (total, used, free)
• GlobalReserve (total, used, free)

$btrfs filesystem usage

• device_size
• device_allocated
• device_unallocated
• device_missing
• used
• free_estimated
• free_statfs (btrfs-progs >= 5.10)
• data_ratio
• metadata_ratio
• global_reserve
• data (Per Device)
• metadata (Per Device)
• system (Per Device)
• unallocated (Per Device)

$btrfs scrub status

• time_taken
• data_extents_scrubbed
• tree_extents_scrubbed
• data_bytes_scrubbed
• tree_bytes_scrubbed
• read_errors
• csum_errors
• verify_errors
• no_csum
• csum_discards
• super_errors
• malloc_errors
• uncorrectable_errors
• unverified_errors
• corrected_errors
• last_physical

Example output

btrfs_stat,pool=/,drive=/dev/mapper/luks-0ff56354-f5c9-45b2-852c-a456641e5722 write_io_errs=0,read_io_errs=0,flush_io_errs=0,corruption_errs=0,generation_errs=0
btrfs_df,type=Data,raidType=single,pool=/ total=30073159680,used=27799445504,free=2273714176
btrfs_df,type=System,raidType=single,pool=/ total=4194304,used=16384,free=4177920
btrfs_df,type=Metadata,raidType=single,pool=/ total=2155872256,used=1173159936,free=982712320
btrfs_df,type=GlobalReserve,raidType=single,pool=/ total=79544320,used=0,free=79544320
btrfs_usage,pool=/ device_size=254339448832,device_allocated=32233226240,device_unallocated=222106222592,device_missing=0,used=28972621824,free_estimated=224379936768,free_statfs=224378888192,data_ratio=1.00,metadata_ratio=1.00,global_reserve=79544320,multiple_profiles=no
btrfs_usage,pool=/,drive=/dev/mapper/luks-0ff56354-f5c9-45b2-852c-a456641e5722 Data=30073159680,Metadata=2155872256,System=4194304,Unallocated=222106222592
btrfs_scrub,pool=/ data_extents_scrubbed=0,tree_extents_scrubbed=0,data_bytes_scrubbed=0,tree_bytes_scrubbed=0,read_errors=0,csum_errors=0,verify_errors=0,no_csum=0,csum_discards=0,super_errors=0,malloc_errors=0,uncorrectable_errors=0,unverified_errors=0,corrected_errors=0,last_physical=0
btrfs_stat,pool=/home,drive=/dev/mapper/luks-0ff56354-f5c9-45b2-852c-a456641e5722 write_io_errs=0,read_io_errs=0,flush_io_errs=0,corruption_errs=0,generation_errs=0
btrfs_df,type=Data,raidType=single,pool=/home total=30073159680,used=27799445504,free=2273714176
btrfs_df,type=System,raidType=single,pool=/home total=4194304,used=16384,free=4177920
btrfs_df,type=Metadata,raidType=single,pool=/home total=2155872256,used=1173159936,free=982712320
btrfs_df,type=GlobalReserve,raidType=single,pool=/home total=79544320,used=0,free=79544320
btrfs_usage,pool=/home device_size=254339448832,device_allocated=32233226240,device_unallocated=222106222592,device_missing=0,used=28972621824,free_estimated=224379936768,free_statfs=224378888192,data_ratio=1.00,metadata_ratio=1.00,global_reserve=79544320,multiple_profiles=no
btrfs_usage,pool=/home,drive=/dev/mapper/luks-0ff56354-f5c9-45b2-852c-a456641e5722 Data=30073159680,Metadata=2155872256,System=4194304,Unallocated=222106222592
btrfs_scrub,pool=/home data_extents_scrubbed=0,tree_extents_scrubbed=0,data_bytes_scrubbed=0,tree_bytes_scrubbed=0,read_errors=0,csum_errors=0,verify_errors=0,no_csum=0,csum_discards=0,super_errors=0,malloc_errors=0,uncorrectable_errors=0,unverified_errors=0,corrected_errors=0,last_physical=0

Usage

1. Install and place btrfs.read.py in location accessible by telgraf. For example /etc/telegraf/btrfs.read.py
2. Grant telegraf permission to sudo btrfs command without password by adding a line similar to the following to /etc/sudoers

telegraf ALL=(root) NOPASSWD: /usr/bin/btrfs filesystem df *, /usr/bin/btrfs device stat *, /usr/bin/btrfs filesystem usage *, /usr/bin/btrfs scrub status *

You can discover the proper btrfs location by issuing command -v btrfs on your system.

3. Update /etc/telegraf/telegraf.conf to call the script

 [[inputs.exec]]
   commands = [
     "python3 /etc/telegraf/btrfs.read.py"
   ]
   timeout = "5s"
   data_format = "influx"

Requirements

• python3
• btrfs-tools