Technical Blog Post
db2stop/db2start failing with I/O errors.
Commonly if db2stop/db2start fail with I/O errors it might point toward a corruptions of some kind at filesystem level. Or, either instance binaries are corrupted or, database catalogs /directories have issues.
But, before getting worried do a quick check with db2diag.log messages with db2stop/db2start
And, then check the db2diag.log entry.
It might fail with I/O error even if an important file system like /home is full. The db2diag.log will show which file system is full.
Then, do a "df -k" and confirm it and clean that up.
Many times DIAGPATH or, log path, archive log path or, even db2 containers put with /home filesystem might cause this kind of issues.