The screenshot attached to the previous message was taken from core stack of 2960's switches and yes server rack is connected to po1 channel. As you can see on the screenshot almost all ports that has host attached to them have outDiscards packets.
The problem started 4 days ago.
Nothing was changed on my network topology for last 30 days and I never seen this much outDiscards numbers on my switches.
Today i have cleared all counters and within 2 hours i dont have any outDiscard packets.
But when it happens i see outDiscards numbers increased on all my switches that have connected interfaces.