Extremely increased disk usage since update 2.4.4_1 -> 2.4.4_2

[jacotec]

Although the update to 2.4.4p2 sounds like a more or less minor update, I have a significantly higher disk write usage right after the update:

Any ideas why this happened and how can I resolve this? The metrics are looking relaxed:

[jacotec]

Looking a bit more in detail, it's heavy disk write processes which seems to happen periodically since the update:

During the highly busy cycles it seems the writes are caused by the "php" process. Is there any way to track down which task causes php to perform these heavy writes?