[19:40] <jerryt> We're running a Dell server with hardware raid.  When we do IO operations such as extracting a large tar file a kworker process pegs IO at 99% or so.  pref points to cpu_startup_entry 
[19:40] <jerryt> Any ideas?
[21:18] <JanC> jerryt: obvious question: is that real hardware RAID or fake hardware RAID which relies on the drivers/CPU to do the hard work? also: how large is the tar file compared to RAM?  and does it use compression and/or encryption?