Hi all, we run Oracle 11r2 at work. It resides on a RHEL 5.8 server, which operates off a SAN.
I recently upgraded to Oracle Cloud Control 12c Release 2. It's a fantastic product. It is, however, reporting periodically that "Disk Device X is 100% busy." When I reported this to our Linux group, they asked how Oracle knew this. This has led me down an interesting path. What Linux command is Oracle running (iostat? sar -d?) to determine that a partition is overwhelmed?
Their response regarding these errors is: "OK, once or twice a day you get these errors--that the disk is at %100--but is there really a problem? We're not getting any SAN errors at all." I'm not sure they're being lazy, they are quite busy.
I guess, at the end of the day though, are these errors really important? Or are they just false positives? They're happening at about the same time each day so I presume it's a cron job kicking off.
They are not errors, they are alerts telling you that your disks are busy. If you are doing large volumes of work you would possibly expect your disks to be busy. How busy and if that is too busy for the work they are doing is the question. I.e. is the work which is being carried out doing too much I/O? That's a question you would need to investigate as to exactly what is happening at those times and if those processes can be made more efficient.