I have a weird issue where my system (ubuntu 19) is showing that MySql 8 is using up 600gb of space, when it should be closer to 250gb.

I ran ubuntu's baobab utility in sudo mode, and it as well, is showing that MySQL is using up 250GB . Any idea what could be taking up the other 250GB?

I also ran this query via SQL, to show table sizes - same story ~250GB, so not sure what else I could try.

     table_schema as `Database`, 
     table_name AS `Table`, 

     round(((data_length + index_length) / 1024 / 1024), 2) `Size in MB` 
FROM information_schema.TABLES 
ORDER BY (data_length + index_length) DESC;

.. I do have a few indexes set up, but most of them on columns containing 0/1s

Thank you in advance for suggestions.

  • 1
    Is your innodb_file_per_table ON or OFF? Also, what's the size of the ibdata1 file? – Jesus Uzcanga Oct 15 '19 at 14:30
  • file per table is on. Not sure how to look up the size of ibdata1 yet for mysql 8/ubuntu . But this should get me started. thanks for pointing me, at least in A direction. – FlyingZebra1 Oct 15 '19 at 15:42
  • 1
    By default mysql install datadir is located at /var/lib/mysql so you can find ibdata1 there, if not there you can find it out by running "show variables like 'datadir';" – Jesus Uzcanga Oct 16 '19 at 19:02
  • 1
    What are the largest few files? (From this, we can more quickly diagnose what happened.) Do this from the filesystem, not SQL. – Rick James Oct 18 '19 at 16:01
  • Thanks everyone for tips - looks like ibdata is 'only' 20ish GB, however, there are a bunch of binlog.00### files, 1 to 14GB each, so looks like that might be the culprit. going to research what those are now. – FlyingZebra1 Oct 20 '19 at 18:53

looks like this command worked for temporary solution:

PURGE BINARY LOGS BEFORE '2019-10-19 22:46:26'; #your date

(mysql manual)

Still working on the long term solution. Per mysql manual - these were the logs of select statements (which are typically huge in my case). Not 100% yet on whether I need these :) In either case, thank you everyone for helping troubleshoot. This was blowing my mind for a bit, but all it took was browsing into the folder itself, and seeing hundreds of huge files!

| improve this answer | |
  • Binary Logs do not store SELECTs. They store actual changes (INSERT,UPDATE,DELETE either as statements or row changes). The only exception is INSERT INTO ... SELECT. – RolandoMySQLDBA Aug 13 at 15:22

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