libvirt image based provisioning using logical volumes - image

Are there known issues with image based provisioning using logical volumes in libvirt? I am getting this error while trying to do the same
Unable to save
Failed to create a compute kvm2 (Libvirt) instance test3.xxx.local: Call
to virNetworkCreateXML failed:
internal error: Child process (/usr/sbin/lvcreate --name
test3.xxx.local-disk1 -L 1K --type snapshot --virtualsize 10485760K -s
/vm-images-pool/images-vol/template_minimal) unexpected exit status 3: 2017-
01-05 00:42:08.133+0000: 12330: debug : virFileClose:102 : Closed fd 29
2017-01-05 00:42:08.133+0000: 12330: debug : virFileClose:102 : Closed fd 31
2017-01-05 00:42:08.133+0000: 12330: debug : virFileClose:102 : Closed fd 27
Volume group name expected (no slash) Run `lvcreate --help' for more
information
This link from Red Hat flags it as a known issue:
https://access.redhat.com/solutions/1995053
That doc has a date of October 20 2015. Not sure if anythig changed after that to support LV.
I tried to satisfy the requirement in that doc by creating a pool based on dir like this:
Setup:
Storage pool vm-images-pool-dir of type dir
Storage pool vm-images-pool of type logical
template_minimal is the image template.
[root#kvm2 libvirt]# virsh vol-list vm-images-pool-dir
Name Path
----------------------------------------------------------------------------
template_minimal /vm-images-pool/images-vol/template_minimal
vm-images-pool storage pool is of type VG with one volume:
images-vol vm-images-pool -wi-ao---- 249.00g
images-vol is mounted under /vm-images-pool/images-vol/
Any insight is appreciated.
Thanks,
TG
=======================================
more details.
Daniel, Thanks. I am a bit confused. I couldn't put the actual commands earlier since I had cleaned them up. I recreated the setup. Here are the commands I used:
virsh pool-define-as vm-images-pool logical --source-dev /dev/mapper/mpathd
virsh pool-build vm-images-pool
virsh pool-start vm-images-pool
virsh vol-create-as vm-images-pool images-vol --capacity 249G
virsh pool-define-as vm-images-pool-dir dir - - - - /vm-images-pool/images- vol/
virsh pool-build vm-images-pool-dir
virsh pool-start vm-images-pool-dir
[root#kvm2 ~]# virsh vol-list vm-images-pool-dir
Name Path
---------------------------------------------------------------------------- --
lost+found /vm-images-pool/images-vol/lost+found
template_minimal /vm-images-pool/images-vol/template_minimal
=======================================
/vm-images-pool/images-vol/template_minimal is the path used for template image
==================================
more tests:
mounted the logical volume at a mount point to match the directory based storage pool:
[root#kvm2 ~]# df -h /vm-images-pool-dir/images-vol
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vm--images--pool-images--vol 245G 1.2G 232G 1% /vm-images- pool-dir/images-vol
[root#kvm2 ~]# virsh vol-list vm-images-pool-dir
Name Path
------------------------------------------------------------------------------
lost+found /vm-images-pool-dir/images-vol/lost+found
template_minimal /vm-images-pool-dir/images-vol/template_minimal
[root#kvm2 ~]#
used /vm-images-pool-dir/images-vol/template_minimal as the template path
same result
Unable to save
Failed to create a compute kvm2 (Libvirt) instance test3.xxx.local: Call
to virNetworkCreateXML failed: internal error: Child process
(/usr/sbin/lvcreate --name test3.xxx.local-disk1 -L 1K --type
snapshot --virtualsize 10485760K - s /vm-images-pool-dir/images-
vol/template_minimal) unexpected exit status 3: 2017-01-05
16:45:10.694+0000: 40712: debug : virFileClose:102 : Closed fd 27 2017-
01-05 16:45:10.694+0000: 40712: debug : virFileClose:102 : Closed fd 29
2017-01-05 16:45:10.694+0000: 40712: debug : virFileClose:102 : Closed fd 24
Volume group name expected (no slash) Run `lvcreate --help' for more
information.
the source of the image is "/vm-images-pool-dir/images-vol/template_minimal" and the guest's target back end is a LV of 10G on another storage pool called "virtual-machines"
Not understanding what the 'lvcreate' commmand is trying to do, shouldnt it at least use "virtual-machines" as the target VG. The tool I am using is Satellite 6.2. I am thinking its something silly that I am overlooking. Not sure where :)
Thanks
TG

Based on the paths in that command, it seems you wanted to create a new file based volume in the /vm-images-pool/images-vol/, ie your "vm-images-pool-dir" pool. The fact that you are seeing an error from "lvcreate" though, suggests that you mistakenly specified "vm-images-pool" to libvirt as the pool to use, causing it to try to create a logical volume instead. You don't show the actual command / API you are running, but check that you've given the right pool name to it.

I know the question has long been asked, but I just hit the same problem and found the answer. I couldn't find the exact virsh command you are using leading to this error, but here I used the following XML file with virsh vol-create libvirtVG logical.xml
<volume >
<name>vol02</name>
<capacity unit='KiB'>2097152</capacity>
<allocation unit='KiB'>0</allocation>
<backingStore>
<path>/dev/libvirtVG/sles15sp1</path>
</backingStore>
</volume>
To be able to get rid of the error I had to set the allocation to the value of the capacity. You can also see that virt-manager is automatically doing it for you:
https://github.com/virt-manager/virt-manager/blob/master/virtinst/storage.py#L646
The equivalent using the virsh vol-create-as command would be:
virsh vol-create-as libvirtVG vol02 2048MiB --allocation 2048MiB \
--backing-vol /dev/libvirtVG/sles15sp1

Related

Slots command in hostfile for mpirun not recognised

I saw another question that seemed similar mpirun: token slots not supported but their solution did not work for me.
I get the error
token slots not supported at this time
when running the command mpirun -hostfile temp.txt hostname
where temp.txt is
hostname1 slots=2
hostname2 slots=2
I have the mpirun version 2021.5
Release Date: 20211102 (id: 9279b7d62).
It did not work to instead write
hostname1:2
hostname2:2
in that case the command runs but it instead does the number of physical processors that are available, which is default.
EDIT: I am adding the full output
[host RAMSES]$ mpirun -hostfile temp.txt hostname
[mpiexec#host] HYD_hostfile_process_tokens (../../../../../src/pm/i_hydra/libhydra/hostfile/hydra_hostfile.c:47): token slots not supported at this time
[mpiexec#host] HYD_hostfile_unique_parse (../../../../../src/pm/i_hydra/libhydra/hostfile/hydra_hostfile.c:232): unable to process token
[mpiexec#host] match_arg (../../../../../src/pm/i_hydra/libhydra/arg/hydra_arg.c:83): match handler returned error
[mpiexec#host] HYD_arg_parse_array (../../../../../src/pm/i_hydra/libhydra/arg/hydra_arg.c:128): argument matching returned error
[mpiexec#host] mpiexec_get_parameters (../../../../../src/pm/i_hydra/mpiexec/mpiexec_params.c:1359): error parsing input array
[mpiexec#host] main (../../../../../src/pm/i_hydra/mpiexec/mpiexec.c:1784): error parsing parameters
So I found that on my version of mpi I had to specify processor placement not in the hostfile, as most of the examples I found do, but rather in the machinefile.
So the new command and file look like:
mpirun -machinefile machine.txt hostname
machine.txt:
host1:2
host2:2

"semmni" is properly set. (more details) Expected Value : 128 Actual Value : 0

i'm trying to install Oracle11g, and this happened, is there a way to fix this?
i had tried to reboot and run the script runfixup.sh still can't resolve the problem.
I'm trying to install Oracle 11gR2 on Oracle Linux 7.4.
While the installer is performing prerequisite checks, we are getting error:
This is a prerequisite condition to test whether the OS kernel parameter semmni is properly set.
More details :
Expected Value : 128
Actual Value : 0
Now if I execute as root:
/sbin/sysctl -a | grep sem
kernel.sem = 32000 1024000000 500 128
Which means that semmni=128.
Can somebody tell me what I'm I doing wrong?
You need to issue the following command
[root#localhost ~]# /sbin/sysctl -p
the changes to take effect.
And then the value(the rightmost one returning below) might be checked by issuing
[root#localhost ~]# more /proc/sys/kernel/sem
32000 1024000000 500 128

Returning a value to a SNMP server via a shell script

Hello my dear coder friends, I have an hard problem to solve.
Me trying to create a SNMP server that tells the status of a physical device. Status of this device is stored in Redis database.
I am using the following .sh for retrieving device status:
tempratureStatus=$(redis-cli get tempratureStatus)
echo "Temperature Status: $tempratureStatus"
if [ "$tempratureStatus" = "True" ]; then
exit 1
else
exit 0
fi;
This script returns whether the device is over heated or not. I am also using following conf file to call this .sh script with SNMP server (see the very last extend postgresfile line):
rwuser bootstrap priv
rwuser demo priv
sysLocation Sitting on the Dock of the Bay
sysContact Me <me#example.org>
sysServices 72
proc mountd
proc ntalkd 4
proc sendmail 10 1
disk / 10000
disk /var 5%
includeAllDisks 10%
load 12 10 5
trapsink localhost public
iquerySecName internalUser
rouser internalUser
defaultMonitors yes
linkUpDownNotifications yes
extend postgresfiles /etc/snmp/scripts/battleshort_local.sh
However, when I use the command,
snmpget -v2c -c public 192.168.1.106 'NET-SNMP-EXTEND-MIB::nsExtendOutLine."postgresfiles".1'
I get the following Error:
NET-SNMP-EXTEND-MIB::nsExtendOutLine."postgresfiles".1 = No Such Object available on this agent at this OID
Whats the problem here I can figure it out. Am I returning undefined? Or am I even returning something?

command output not captured by shell script when invoked by snmp pass

The problem
SNMPD is correctly delegating SNMP polling requests to another program but the response from that program is not valid. A manual run of the program with the same arguments is responding correctly.
The detail
I've installed the correct LSI raid drivers on a server and want to configure SNMP. As per the instructions, I've added the following to /etc/snmp/snmpd.conf to redirect SNMP polling requests with a given OID prefix to a program:
pass .1.3.6.1.4.1.3582 /usr/sbin/lsi_mrdsnmpmain
It doesn't work correctly for SNMP polling requests:
snmpget -v1 -c public localhost .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.1
I get the following response:
Error in packet
Reason: (noSuchName) There is no such variable name in this MIB.
Failed object: SNMPv2-SMI::enterprises.3582.5.1.4.2.1.2.1.32.1
What I've tried
SNMPD passes two arguments, -g and <oid> and expects a three line response <oid>, <data-type> and <data-value>.
If I manually run the following:
/usr/sbin/lsi_mrdsnmpmain -g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
I correctly get a correct three line response:
.1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
integer
30
This means that the pass command is working correctly and the /usr/sbin/lsi_mrdsnmpmain program is working correctly in this example
I tried replacing /usr/sbin/lsi_mrdsnmpmain with a bash script. The bash script delegates the call and logs the supplied arguments and output from the delegated call:
#!/bin/bash
echo "In: '$#" > /var/log/snmp-pass-test
RETURN=$(/usr/sbin/lsi_mrdsnmpmain $#)
echo "$RETURN"
echo "Out: '$RETURN'" >> /var/log/snmp-pass-test
And modified the pass command to redirect to the bash script. If I run the bash script manually /usr/sbin/snmp-pass-test -g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0 I get the correct three line response as I did when I ran /usr/sbin/lsi_mrdsnmpmain manually and I get the following logged:
In: '-g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
Out: '.1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
integer
30'
When I rerun the snmpget test, I get the same Error in packet... error and the bash script's logging shows that the captured delegated call output is empty:
In: '-g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.0
Out: ''
If I modify the bash script to only echo an empty line I also get the same Error in packet... message.
I've also tried ensuring that the environment variables that are present when I manually call /usr/sbin/lsi_mrdsnmpmain are the same for the bash script but I get the same empty output.
Finally, my questions
Why would the bash script behave differently in these two scenarios?
Is it likely that the problem that exists with the bash scripts is the same as originally noticed (manually running program has different output to SNMPD run program)?
Updates
eewanco's suggestions
What user is running the program in each scenario?
I added echo "$(whoami)" > /var/log/snmp-pass-test to the bash script and root was added to the logs
Maybe try executing it in cron
Adding the following to root's crontab and the correct three line response was logged:
* * * * * /usr/sbin/lsi_mrdsnmpmain -g .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.1 >> /var/log/snmp-test-cron 2>&1
Grisha Levit's suggestion
Try logging the stderr
There aren't any errors logged
Checking /var/log/messages
When I run it via SNMPD, I get MegaRAID SNMP AGENT: Error in getting Shared Memory(lsi_mrdsnmpmain) logged. When I run it directly, I don't. I've done a bit of googling and I may need lm_sensors installed; I'll try this.
I installed lm_sensors & compat-libstdc++-33.i686 (the latter because it said it was a pre-requisite from the instructions and I was missing it), uninstalled and reinstalled the LSI drivers and am experiencing the same issue.
SELinux
I accidently stumbled upon a page about extending snmpd with scripts and it says to check the script has the right SELinux context. I ran grep AVC /var/log/audit/audit.log | grep snmp before and after running a snmpget and the following entry is added as a direct result from running snmpget:
type=AVC msg=audit(1485967641.075:271): avc: denied { unix_read unix_write } for pid=5552 comm="lsi_mrdsnmpmain" key=558265 scontext=system_u:system_r:snmpd_t:s0 tcontext=system_u:system_r:initrc_t:s0 tclass=shm
I'm now assuming that SELinux is causing the call to fail; I'll dig further...see answer for solution.
strace (eewanco's suggestion)
Try using strace with and without snmp and see if you can catch a system call failure or some additional hints
For completeness, I wanted to see if strace would have hinted that SELinux was denying. I had to remove the policy packages using semodule -r <policy-package-name> to reintroduce the problem then ran the following:
strace snmpget -v1 -c public localhost .1.3.6.1.4.1.3582.5.1.4.2.1.2.1.32.1 >> strace.log 2>&1
The end of strace.log is as follows and unless I'm missing something, it doesn't seem to provide any hints:
...
sendmsg(3, {msg_name(16)={sa_family=AF_INET, sin_port=htons(161), sin_addr=inet_addr("127.0.0.1")}, msg_iov(1)= [{"0;\2\1\0\4\20public\240$\2\4I\264-m\2"..., 61}], msg_controllen=32, {cmsg_len=28, cmsg_level=SOL_IP, cmsg_type=, ...}, msg_flags=0}, MSG_DONTWAIT|MSG_NOSIGNAL) = 61
select(4, [3], NULL, NULL, {0, 999997}) = 1 (in [3], left {0, 998475})
brk(0xab9000) = 0xab9000
recvmsg(3, {msg_name(16)={sa_family=AF_INET, sin_port=htons(161), sin_addr=inet_addr("127.0.0.1")}, msg_iov(1)= [{"0;\2\1\0\4\20public\242$\2\4I\264-m\2"..., 65536}], msg_controllen=0, msg_flags=0}, MSG_DONTWAIT) = 61
write(2, "Error in packet\nReason: (noSuchN"..., 81Error in packet
Reason: (noSuchName) There is no such variable name in this MIB.
) = 81
write(2, "Failed object: ", 15Failed object: ) = 15
write(2, "SNMPv2-SMI::enterprises.3582.5.1"..., 48SNMPv2- SMI::enterprises.3582.5.1.4.2.1.2.1.32.1
) = 48
write(2, "\n", 1
) = 1
brk(0xaa9000) = 0xaa9000
close(3) = 0
exit_group(2) = ?
+++ exited with 2 +++
It was SELinux that was denying snmpd a delegated call to /usr/sbin/lsi_mrdsnmpmain (and probably beyond).
To identify it, I ran grep AVC /var/log/audit/audit.log and for each entry, I ran the following:
echo "<grepped-output>" | audit2allow -a -M <filename>
This creates a SELinux policy package that should allow the delegated call through. The package is then loaded using the following:
semodule -i <filename>.pp
I had to do this 5 times as there were different causes of denial (unix_read unix_write, associate, read write). I'll look to combine the modules into one.
Now when I run snmpget I get the correct delegated output:
SNMPv2-SMI::enterprises.3582.5.1.4.2.1.2.1.32.1 = INTEGER: 34

set additional folder for snmp MIBs

I am rebuilding an Icinga server that has been left behind by a previous employee. I have everything up and running, except for a bunch of MIB files for 3com switches that I cannot get to work.
The server is a CentOS 6 OpenVZ container.
In the original server there is a bunch of mib files in the default location at /usr/share/snmp/mibs/ and the 3com ones at /usr/share/snmp/mibs/3Com_4500/MIBs. The 3Com mibs work fine:
/usr/lib/nagios/plugins/check_snmp -H 10.10.111.11 -P 2c -C public -o hwDevMFanStatus.65536 -s "active(1)" -m A3COM-HUAWEI-LswDEVM-MIBSNMP OK - active(1) |
In the new server, the MIBs in the 3com folder do not get acknowledged and I get errors like the following:
/usr/lib/nagios/plugins/check_snmp -H 10.10.111.11 -P2c -C someuser -o hwDevMFanStatus.65536 -s "active(1)" -m A3COM-HUAWEI-LswDEVM-MIB
External command error: No log handling enabled - turning on stderr logging
Cannot find module (A3COM-HUAWEI-LswDEVM-MIB): At line 0 in (none)
hwDevMFanStatus.65536: Unknown Object Identifier (Sub-id not found: (top) -> hwDevMFanStatus)
/etc/snmp/snmpd.conf is identical for both servers and so is /etc/sysconfig/snmp.
set does not show any ENV variable related to snmp or mib.
Thanks
You are confusing snmpd.conf and snmp.conf the former being the configuration file for the SNMP daemon whereas Net-SNMP applications use snmp.conf.
The mibs/mibdirs directives you are interested in would be specified in snmp.conf (see also man snmp.conf.

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