I have encountered a system with five FC shelves, each having dual connections to a single controller and the disks in RAID groups across these shelves are mixed between each channel, below is an example.
Hi Ismopuuronen, I know they are dual pathed. It's just that I'm more used to seeing the disks listed twice, once for each channel, rather than one list from a sysconfig with disks listed on only one channel, apparently at random. Is this perhaps related to this system only having one controller. All the others are HA.
>sysconfig -r shows where the disks belongs and the active path, it also shows if there are partner disks. >sysconfig -a shows disks twice and more, where the shelfs are connected etc. >storage show disk -p could be what you are looking for now?
>disk show -v is good way to determine ownership of the disks.
Pretty sure I know the ownership (one controller ). It was more the question of since some disks show on 4b and some on 0b I was wondering if the I/O across aggr was also along these channels, so priority differs between disks in an aggr, or even if it was possible to define the I/O path per disk though given the way the systems work I can't see the point on a single controller setup.
netapp supports 2 pathes to a disk but will only activly use 1. So it will pull half of the disk i/o through way a and other half through way b. if one path dies, it might switch over to way a only, you can correct that using "stoarge load balance" and it will go 50/50 again.
Thanks Thomas, I'm still a little uncertain why the disks are unevenly distributed across two channels on a single controller but it seems to be working. I would have expected them to report the channel on which I/O is actually running or if load balanced to see a 50/50 distribution. It's an inherited system so it may have achieved its current state over time. I'll try load balance and see if everything returns to a more coherent state.