We are using this san last 4 year without any issue
But last 3 months ago one of raid control card lost and we replaced with
other one and it's working fine

But some reason we are getting "virtual disk preferred path failed " on
one of the virtual disk. So every time we have to set the prefered path manually
and its works fine for 15 days but after 15 days (during media scan)
it's back to another path with this error.

So could you please help me with this issue.