# GC not Working


+ Possible symptoms
  + Safe point not pushing forward
  + Disk space not reclaimed after drop table
  + ...
+ Possible causes
  + The config format is incorrect
  + Some living transactions blocks `GC`
  + Some service safe points blocks `GC`
  + Resolve Locks failed
  + User extended `GC` life time from a smaller value (expected)
  + `GC` runs normally but too slow
  + **`gc_life_time`** or **`gc_run_interval`** configured too long (expected, check the config in **`mysql.tidb`**)
  + Extend **`gc_life_time`** manually (expected, check the config in **`mysql.tidb`**)

------------------------------------------------------------