for performance reasons I have added a new separate zpool on an SSD which I designated ssdpool. I was going to put VirtualBox Disk images on that pool. However for a reason I haven't figured out yet, the entire systems performance has decreased significantly. The disk IO on the ssdpool is < 10Mb/s.
There is a single SSD for the ssdpool with 256 GB
and 2x 1000GB off the shelf hard disks
with 8GB RAM.
I was not going for a hybrid approach here, ie. using the SSD as a cache but designated for it's own zpool. Eventually I was going to get a second one to mirror the SSD.
Any clues here why the disk IO decreased instead of the other way around?
I'm not sure I understand everything below but let's start with the poor I/O performance of this one disk ssdpool.
How was this pool created? Can you provide the syntax? Was it created with a slice or the whole disk?
I think you are also saying the entire system's performance is bad but I'm not following why.
as it turns out, the SSD seems to have nothing to with at all. IIRC the drastic disk IO performance decrease happened right at the same time when I upgraded my system from Oracle Solaris 11_11 to 11.1. It was then when I decided to buy a SSD to boost performance.
Do you happen to know if the upgrade would have made some tuning necessary on older systems?