[Lustre-discuss] ll_ost_creat_* goes bersek (100% cpu used - OST disabled)

[Adrian Ulrich]

Hi Alexey,

> in general soft-lookup isn't error, that just notice about some operation is need too many time (more then 10s i think).
> attached soft-lookup say - OST is busy with creating objects after MDS<>OST reconnect, 

Yes, i know that a soft-lockup doesn't mean that i hit a bug but having ll_ost_creat_* wasting 100% CPU
doesn't seem to be normal.

> i think you have too busy disks or overloaded node.

Disk %busy is < 5% for all attached disks.
The OST is doing almost nothing (there are a few read()'s, that's all)


> if you have slow disks - client can be disconnected before they request is processing, and that request blocked to reconnect from that client.

The recovery of the clients seems to be ok: all clients can write/read data from the OST but
there is something wrong between the MDS<->OST0005.

But this might just be a side-effect of the ll_ost_creat_* issue :-/

Regards,
 Adrian


-- 
 RFC 1925:
   (11) Every old idea will be proposed again with a different name and
        a different presentation, regardless of whether it works.