Note: This bug is displayed in read-only format because
the product is no longer active in Red Hat Bugzilla.
RHEL Engineering is moving the tracking of its product development work on RHEL 6 through RHEL 9 to Red Hat Jira (issues.redhat.com). If you're a Red Hat customer, please continue to file support cases via the Red Hat customer portal. If you're not, please head to the "RHEL project" in Red Hat Jira and file new tickets here. Individual Bugzilla bugs in the statuses "NEW", "ASSIGNED", and "POST" are being migrated throughout September 2023. Bugs of Red Hat partners with an assigned Engineering Partner Manager (EPM) are migrated in late September as per pre-agreed dates. Bugs against components "kernel", "kernel-rt", and "kpatch" are only migrated if still in "NEW" or "ASSIGNED". If you cannot log in to RH Jira, please consult article #7032570. That failing, please send an e-mail to the RH Jira admins at rh-issues@redhat.com to troubleshoot your issue as a user management inquiry. The email creates a ServiceNow ticket with Red Hat. Individual Bugzilla bugs that are migrated will be moved to status "CLOSED", resolution "MIGRATED", and set with "MigratedToJIRA" in "Keywords". The link to the successor Jira issue will be found under "Links", have a little "two-footprint" icon next to it, and direct you to the "RHEL project" in Red Hat Jira (issue links are of type "https://issues.redhat.com/browse/RHEL-XXXX", where "X" is a digit). This same link will be available in a blue banner at the top of the page informing you that that bug has been migrated.
Created attachment 1694982[details]
FAF report of the crash
Description of problem:
pcp-pmda-lio is crashing when target_core_mod kernel module is not loaded. There are two issues with this:
1) The fact the target_core_mod needs to be explicitly loaded for pcp-pmda-lio to work is not documented anywhere.
2) Even if the target_core_mod kernel module is not loaded, pcp-pmda-lio should not crash. It should shut-down gracefully.
Version-Release number of selected component (if applicable):
I can reproduce this from pcp-pmda-lio-4.3.2-2.el8 to pcp-pmda-lio-5.1.1-1.el8
How reproducible:
Intermittently
Steps to Reproduce:
1. Install pcp-pmda-lio on a fresh RHEL-8.3 release
# yum install -y pcp-pmda-lio pcp-zeroconf
2. Install the PMDA
# cd /var/lib/pcp/pmdas/lio && ./Install
3. Try to get a value from the lio PMDA
# pmval lio.summary.total_luns
Actual results:
# pmval lio.summary.total_luns
pmval: pmGetInDom(142.0): Resource temporarily unavailable
# tail /var/log/pcp/pmcd/lio.log
...
[Thu Jun 4 02:26:18] pmdalio(15276) Error: prefetch: callback failed
[Thu Jun 4 02:30:31] pmdalio(15276) Error: prefetch: callback failed
[Thu Jun 4 02:31:42] pmdalio(15276) Error: preinstance: callback failed
If abrt is enabled then a FAF report is generated (see the attachment).
This is a snip from the backtrace log:
<backtrace>
Traceback (most recent call last):
File "/var/lib/pcp/pmdas/lio/pmdalio.python", line 256, in lio_fetch
self.refresh()
File "/var/lib/pcp/pmdas/lio/pmdalio.python", line 193, in refresh
r = root.RTSRoot()
File "/usr/lib/python3.6/site-packages/rtslib_fb/root.py", line 85, in __init__
modprobe('target_core_mod')
File "/usr/lib/python3.6/site-packages/rtslib_fb/utils.py", line 434, in modprobe
raise RTSLibError("Could not load module: %s" % module)
rtslib_fb.utils.RTSLibError: Could not load module: target_core_mod
</backtrace>
Expected results:
* pcp-pmda-lio handles exceptions from RTS lib
* The need for explicit load of target_core_mod is documented
Additional info:
Resolved upstream. Note I've not made any changes to the
man page, after reviewing it, as I don't think we should
be encouraging manual kernel module loading. Any modules
needed will be loaded by the iSCSI target initialization
code (not part of PCP) - if they're not loaded then there
are no devices we should be reporting on so the behaviour
(and related doc) is now as it should be I think.
commit 2f48006ecaab3ee4c0c318dc62b24df71659874c (HEAD -> master)
Author: Nathan Scott <nathans>
Date: Mon Jul 6 16:10:40 2020 +1000
pmdalio: wrap refresh routine with exception handling
When no iSCSI devices have been created yet the kernel
modules are not necessarily loaded. This'll result in
exceptions from rtslib - so mask these (logged once).
Resolves Red Hat BZ #1843792.
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.
For information on the advisory (pcp bug fix and enhancement update), and where to find the updated
files, follow the link below.
If the solution does not work for you, open a new bug report.
https://access.redhat.com/errata/RHBA-2021:1754
Created attachment 1694982 [details] FAF report of the crash Description of problem: pcp-pmda-lio is crashing when target_core_mod kernel module is not loaded. There are two issues with this: 1) The fact the target_core_mod needs to be explicitly loaded for pcp-pmda-lio to work is not documented anywhere. 2) Even if the target_core_mod kernel module is not loaded, pcp-pmda-lio should not crash. It should shut-down gracefully. Version-Release number of selected component (if applicable): I can reproduce this from pcp-pmda-lio-4.3.2-2.el8 to pcp-pmda-lio-5.1.1-1.el8 How reproducible: Intermittently Steps to Reproduce: 1. Install pcp-pmda-lio on a fresh RHEL-8.3 release # yum install -y pcp-pmda-lio pcp-zeroconf 2. Install the PMDA # cd /var/lib/pcp/pmdas/lio && ./Install 3. Try to get a value from the lio PMDA # pmval lio.summary.total_luns Actual results: # pmval lio.summary.total_luns pmval: pmGetInDom(142.0): Resource temporarily unavailable # tail /var/log/pcp/pmcd/lio.log ... [Thu Jun 4 02:26:18] pmdalio(15276) Error: prefetch: callback failed [Thu Jun 4 02:30:31] pmdalio(15276) Error: prefetch: callback failed [Thu Jun 4 02:31:42] pmdalio(15276) Error: preinstance: callback failed If abrt is enabled then a FAF report is generated (see the attachment). This is a snip from the backtrace log: <backtrace> Traceback (most recent call last): File "/var/lib/pcp/pmdas/lio/pmdalio.python", line 256, in lio_fetch self.refresh() File "/var/lib/pcp/pmdas/lio/pmdalio.python", line 193, in refresh r = root.RTSRoot() File "/usr/lib/python3.6/site-packages/rtslib_fb/root.py", line 85, in __init__ modprobe('target_core_mod') File "/usr/lib/python3.6/site-packages/rtslib_fb/utils.py", line 434, in modprobe raise RTSLibError("Could not load module: %s" % module) rtslib_fb.utils.RTSLibError: Could not load module: target_core_mod </backtrace> Expected results: * pcp-pmda-lio handles exceptions from RTS lib * The need for explicit load of target_core_mod is documented Additional info: