Description of problem:
A SAN Booted RHEL 5.7z-KVM host, with its root LUN mapped to NetApp Storage array over FC, hangs during IO with fabric faults.
When the host hangs, no network service (ssh/telnet/rsh) is operational. Multiple kernel messages logged in syslog reporting about CPU lock-ups (soft lockup - CPU#10 stuck for X seconds) on different processes like quemu-kvm,multipathd,kjournald etc
Version-Release number of selected component (if applicable):
Host Kernel : 2.6.18-274.18.1.el5
Multipath (device-mapper-multipath-0.4.7-46.el5)
LVM2 (lvm2-2.02.84-6.el5)
HBA : Qlogic 2562
Driver : 8.03.07.03.05.07-k
Firmware : 5.03.16 (95)
How reproducible:
frequently.
Steps to Reproduce:
1. Map 40 LUNs (with 4 FC paths each, i.e, 160 SCSI devices) from controllers
and configure multipath devices on the host.
2.Create 10 LVs on the dm-multipath devices.
3.Create 4 VMs on 4 LVs. And map rest of the LVs to the VMs.
4.Start IO to the LVs and Introduce fabric faults repeatedly.
Actual results:
Hypervisor hangs.
Expected results:
Should not hang.
Additional info:
It happens only on Qlogic host.
Hello
Can you be more specific about the comment "introduce fabric faults"
Also how long does the hypervisor hang?, does it recover.
Can you share the message logs.
More data is needed here please.
Is it possible to obtain kernel traces - so it could be seen, where the process are being stuck ?
Comment 3RHEL Program Management
2014-01-29 10:36:50 UTC
This request was evaluated by Red Hat Product Management for inclusion
in a Red Hat Enterprise Linux release. Product Management has
requested further review of this request by Red Hat Engineering, for
potential inclusion in a Red Hat Enterprise Linux release for currently
deployed products. This request is not yet committed for inclusion in
a release.