Ceph often appears as a troubleshooting solution for slow request

Phenomenon:

The question of request blocked is often found through the Ceph-w log (if the virtual machine system runs on Ceph, it will find a serious lag)

Investigation:

1, through the Dstat did not find a significant bottleneck (Dstat-tndr 2)

2, through the Iostat also found no obvious bottleneck (IOSTAT-DX 2)

3, through the Netstat also did not find the Storage Network network card send queue or receive queue has a significant backlog (Netstat-an)

4. There are four types of problems that are not officially explained by ceph (equipment broken down, etc.)

Solve:

Finally also many attempts, found that the storage network card LRO shut down, return to normal.

For LRO,LSO,GRO,GSO,TSO,UFO please refer to http://www.cnblogs.com/CasonChan/p/5166708.html

Ceph often appears as a troubleshooting solution for slow request