ibdata1 writes

innodb with file per tablespace set.

altering a single large table to partition 100 smaller.

Seems to be a significant amount of writes happening to ibdata1 file (now 1.5 GB) even though there are no database tables within…

anyone know what it could be?


innodb transaction log?

I dont think so, I have log files in ib_logfile0 and ib_logfile 1…

undo segment is still located in ibdata1

Heavy IO usually means you have some long running transactions which need a lot of space in undo segment, otherwise it would just stay in buffer pool.