Hi,
We have a server with postgresql 9.4.12 on ubuntu.
There has been a sudden rise in the amount of disk space used by postgresql, causing a diskspace error:
2020-01-22 17:24:37 CET db: ip: us: PANIC: could not write to file "pg_xlog/xlogtemp.23346": No space left on device
2020-01-22 17:24:37 CET db: ip: us: LOG: WAL writer process (PID 23346) was terminated by signal 6: Aborted
2020-01-22 17:24:37 CET db: ip: us: LOG: terminating any other active server processes
The disk was at roughly 75% before and something or someone added 150 GB to the database, bringing the disk space usage to 100%.
The query that got the initial error was creating a rather large table, but it is not confirmed that this is the only source of the large-ish data amount. But it is possible.
Now i can see in pg_stat_database and postgresql/9.4/main/base/pgsql_tmp that there is 90GB of temporary files in the database.
Could the amount of temp files be caused by the unfinished query? I'm not sure how strong Signal 6 is exactly.
And also: How can i make postgres clean up the files?
Can it be done without restarting the cluster?
Will restarting it help?