How to recover from "Display output is not active"
by Jeffrey Walton
Hi Everyone,
I'm working on Ubuntu 22.04.5, amd64, fully patched. It provides QEMU
1:6.2+dfsg-2ubuntu6.26 and libvirt 8.0.0-1ubuntu7.11.
The problem I am experiencing is, when the host machine blanks the
monitor, I lose the display on the guest when I sit back down at the
computer and wake the monitor. The error message (?) in the guest
window is, "Display output is not active." The condition happens with
both VIRTIO and VGA models. Also see <https://imgur.com/a/tEp73k2>.
I have not found a workaround to stop it from happening or recover
after it happens. I have to Force Off the VM and then restart the VM
to the display back.
My host power configuration is: disable sleep, suspend, hibernate and
hybrid-sleep via systemd's systemctl. However, I allow the monitor to
be turned off after 15 minutes of inactivity. My guest power
configuration is whatever the distro provides.
Based on my searching, others have experienced the problem. And one
fellow says switching to the VGA model fixed it for him. (But no joy
for me).
Does anyone have any suggestions for a work around?
Thanks in advance. (And my apologies if this is the wrong list).
Jeff
6 days, 18 hours
RBD Namespace
by Rodrigo Prieto
Hello, I want to connect to an RBD pool specifying the namespace, but it
doesn’t work. If I connect directly to the pool, it works. For example:
<source protocol="rbd" name="rbd-pool/vm">
But when I try to specify the namespace like this, I cannot connect:
<source protocol="rbd" name="rbd-pool/vm" namespace="vms">
<source protocol="rbd" name="rbd-pool/vms/vm">
Error al iniciar dominio: error interno: process exited while connecting to
monitor: 2025-06-20T22:54:55.076193Z qemu-system-x86_64: -blockdev
{"driver":"rbd","pool":"rbd-pool","image":"loli/mari","server":[{"host":"ceph-admin","port":"6789"}],"user":"admin","auth-client-required":["cephx","none"],"key-secret":"libvirt-2-storage-auth-secret0","node-name":"libvirt-2-storage","auto-read-only":true,"discard":"unmap"}:
error reading header from loli/mari: No such file or directory
Using the rbd command from the terminal, I can connect both ways; the error
occurs only with libvirt.
I’m using the following versions on Debian 12:
libvirtd (libvirt) 9.0.0
QEMU emulator version 7.2.17 (Debian 1:7.2+dfsg-7+deb12u13)
Copyright (c) 2003-2022 Fabrice Bellard and the QEMU Project developers
Thanks.
2 weeks, 6 days
Re: Question about managed/unmanaged persistent reservation disks
by Michal Prívozník
On 6/10/25 19:15, Simon Coter wrote:
> Adding users DL to possibly reach out a wider audience.
>
> Simon
>
Dropping devel list as this is users list material.
>> On Jun 9, 2025, at 7:28 PM, Annie Li <annie.li(a)oracle.com> wrote:
>>
>> Hello,
>>
>> I've been looking at source code related to persistent reservation and
>> got confused a little bit about managed persistent reservation disks.
>> For disk configured with 'managed=yes' as the following,
>>
>> <reservations managed='yes'>
>> <source type='unix' path='/var/lib/libvirt/qemu/domain-7-
>> brml10g19-iscsi-rese/pr-helper0.sock' mode='client'/>
>> </reservations>
>>
>> libvirt is responsible for starting a pr-helper program with a
>> specific associated socket file. The following source code shows that
>> there is only one pr-helper and socket file associated with the
>> managed disks for one VM.
>>
>> const char *
>> qemuDomainGetManagedPRAlias(void)
>> {
>> return "pr-helper0";
>> }
>> char *
>> qemuDomainGetManagedPRSocketPath(qemuDomainObjPrivate *priv)
>> {
>> return g_strdup_printf("%s/%s.sock", priv->libDir,
>> qemuDomainGetManagedPRAlias());
>> }
>>
>> So if the VM is booted with multiple disks configured with
>> 'managed=yes' for reservation, I suppose these multiple disks share
>> the this managed pr-helper and socket file. However, per the qemu
>> document, https://www.qemu.org/docs/master/interop/pr-helper.html
>> <https://www.qemu.org/docs/master/interop/pr-helper.html>
>> "It is invalid to send multiple commands concurrently on the same
>> socket. It is however possible to connect multiple sockets to the
>> helper and send multiple commands to the helper for one or more file
>> descriptors."
>>
This certainly did not use to be the case. IIRC this was discussed in
this very old thread:
https://lists.libvirt.org/archives/list/devel@lists.libvirt.org/thread/UU...
Maybe QEMU has some internal lock that does the right thing and
serializes requests?
Michal
>> Due to this limitation above, only one persistent reservation disk is
>> allowed as managed in theory. However, libvirt doesn't throw out any
>> error or warning when the VM is booted up with multiple managed
>> persistent reservation disks. I am wondering if I've missed something
>> here?
>>
>> For unmanaged persistent reservation disks, libvirt doesn't start the
>> pr-helper program for them. It is user's responsibility to start this
>> program with customized socket file per disk, but the complexity
>> increases with numbers of persistent reservation disks, especially in
>> the case of hotplug/hotunplog. Is there any plan to support multiple
>> managed persistent reservation disks with separate pr-helper/socket file?
>>
>> Any suggestions/clarifications are greatly appreciated.
>>
>> Thanks
>>
>> Annie
>>
>
3 weeks, 4 days
significant delay live migrating a vm with an sr-iov interface
by Paul B. Henson
I'm using libvirt under Debian 12 (9.0.0-4+deb12u2 w/qemu
7.2+dfsg-7+deb12u12).
I have a vm using sr-iov, and configured it with a failover macvtap
interface so I could live migrate it. However, there is a significant
delay at the end of the migration resulting in a lot of lost traffic. If
I only have the macvtap interface, migration completes immediately at
the end of the transfer of memory with no loss of traffic.
I enabled debug logging, and found the following. On the source system,
it logs that the system is paused for the cutover:
2025-04-30 01:08:12.526+0000: 1696180: debug :
qemuMigrationAnyCompleted:1957 : Migration paused before switchover
at that point, for almost a minute, the source system just keeps
printing the same statistics:
2025-04-30 01:08:12.923+0000: 1696272: info :
qemuMonitorJSONIOProcessLine:208 : QEMU_MONITOR_RECV_REPLY:
mon=0x7f8fdc0ad2f0 reply={"return": {"expected-downtime": 300, "status":
"device", "setup-time": 297, "total-time": 26107, "ram": {"total":
137452265472, "postcopy-requests": 0, "dirty-sync-count": 3,
"multifd-bytes": 2821784576, "pages-per-second": 297855,
"downtime-bytes": 13208, "page-size": 4096, "remaining": 0,
"postcopy-bytes": 0, "mbps": 9786.9158461538464, "transferred":
3117658825, "dirty-sync-missed-zero-copy": 0, "precopy-bytes":
295861041, "duplicate": 32874480, "dirty-pages-rate": 56, "skipped": 0,
"normal-bytes": 2804301824, "normal": 684644}}, "id": "libvirt-577"}
[...]
2025-04-30 01:09:06.290+0000: 1696272: info :
qemuMonitorJSONIOProcessLine:208 : QEMU_MONITOR_RECV_REPLY:
mon=0x7f8fdc0ad2f0 reply={"return": {"expected-downtime": 300, "status":
"device", "setup-time": 297, "total-time"
: 79474, "ram": {"total": 137452265472, "postcopy-requests": 0,
"dirty-sync-count": 3, "multifd-bytes": 2821784576, "pages-per-second":
297855, "downtime-bytes": 13208, "page-size": 4096, "remaining": 0,
"postcopy-bytes"
: 0, "mbps": 9786.9158461538464, "transferred": 3117658825,
"dirty-sync-missed-zero-copy": 0, "precopy-bytes": 295861041,
"duplicate": 32874480, "dirty-pages-rate": 56, "skipped": 0,
"normal-bytes": 2804301824, "normal":
684644}}, "id": "libvirt-629"}
until finally it completes:
2025-04-30 01:09:06.327+0000: 1696272: info :
qemuMonitorJSONIOProcessLine:203 : QEMU_MONITOR_RECV_EVENT:
mon=0x7f8fdc0ad2f0 event={"timestamp": {"seconds": 1745975346,
"microseconds": 327382}, "event": "MIGRATION", "dat
a": {"status": "completed"}}
On the destination side, it says something about negotiating failover
for the network link:
2025-04-30 01:08:12.923+0000: 1384503: info :
qemuMonitorJSONIOProcessLine:203 : QEMU_MONITOR_RECV_EVENT: mon=
0x7fc7900ab2f0 event={"timestamp": {"seconds": 1745975292,
"microseconds": 922783}, "event": "FAILOVER_NEGOTIA
TED", "data": {"device-id": "ua-sr-iov-backup"}}
Then nothing happens for about a minute until it says it is done:
2025-04-30 01:09:06.328+0000: 1384503: debug :
qemuMonitorJSONIOProcessLine:189 : Line [{"timestamp": {"second
s": 1745975346, "microseconds": 327991}, "event": "MIGRATION", "data":
{"status": "completed"}}]
Any thoughts on what is going on here to cause this delay? It's clearly
somehow related to the sv-iov component of the migration.
Thanks much…
1 month
virt-install iscsi direct - Target not found
by kgore4 une
When I try to use an iscsi direct pool in a "--disk" clause for
virt-install, I get error "iSCSI: Failed to connect to LUN : Failed to log
in to target. Status: Target not found(515)". I've seen that sort of error
before when the initiator name isn't used. The SAN returns different LUNS
depending on the initiator.
I've run out of ideas on what to try next. Any advice welcome. I've
included what I thought was relevent below.
klint.
The disk parameter to virt-install is (it's part of a script but the
variables are correct when executed)
[code]
--disk
vol=${poolName}/unit:0:0:${vLun1},xpath.set="./source/initiator/iqn/@name='iqn.2024-11.localdomain.agbu.agbuvh1:${vName}'"
\
[/code]
I added the xpath.set as I noticed that the initiator wasn't in the debug
output of the disk definition and it didn't work without it either.
The iscsi direct pool is defined and it appears to work - it's active and
vol-list shows the correct luns.
Using --debug on virt install, I can see the drive is detected early in the
process as it's got the size of the drive.
[code]
[Wed, 19 Feb 2025 16:43:33 virt-install 2174805] DEBUG (cli:3554) Parsed
--disk volume as: pool=agbu-ldap1 vol=unit:0:0:3
[Wed, 19 Feb 2025 16:43:33 virt-install 2174805] DEBUG (disk:648)
disk.set_vol_object: volxml=
<volume type='network'>
<name>unit:0:0:3</name>
<key>ip-10.1.4.3:3260-iscsi-iqn.1992-09.com.seagate:01.array.00c0fff6c846-lun-3</key>
<capacity unit='bytes'>49996103168</capacity>
<allocation unit='bytes'>49996103168</allocation>
<target>
<path>ip-10.1.4.3:3260-iscsi-iqn.1992-09.com.seagate:01.array.00c0fff6c846-lun-3</path>
</target>
</volume>
[Wed, 19 Feb 2025 16:43:33 virt-install 2174805] DEBUG (disk:650)
disk.set_vol_object: poolxml=
<pool type='iscsi-direct'>
<name>agbu-ldap1</name>
<uuid>1c4ae810-9bae-433c-a92f-7d3501b6ba80</uuid>
<capacity unit='bytes'>49996103168</capacity>
<allocation unit='bytes'>49996103168</allocation>
<available unit='bytes'>0</available>
<source>
<host name='10.1.4.3'/>
<device path='iqn.1992-09.com.seagate:01.array.00c0fff6c846'/>
<initiator>
<iqn name='iqn.2024-11.localdomain.agbu.agbuvh1:agbu-ldap'/>
</initiator>
</source>
</pool>
[/code]
The generated initial_xml for the disk looks like
[code]
<disk type="network" device="disk">
<driver name="qemu" type="raw"/>
<source protocol="iscsi"
name="iqn.1992-09.com.seagate:01.array.00c0fff6c846-lun-3">
<host name="10.1.4.3"/>
<initiator>
<iqn name="iqn.2024-11.localdomain.agbu.agbuvh1:agbu-ldap"/>
</initiator>
</source>
<target dev="vda" bus="virtio"/>
</disk>
[/code]
The generated final_xml looks like
[code]
<disk type="network" device="disk">
<driver name="qemu" type="raw"/>
<source protocol="iscsi"
name="iqn.1992-09.com.seagate:01.array.00c0fff6c846-lun-3">
<host name="10.1.4.3"/>
<initiator>
<iqn name="iqn.2024-11.localdomain.agbu.agbuvh1:agbu-ldap"/>
</initiator>
</source>
<target dev="vda" bus="virtio"/>
</disk>
[/code]
The full error is
[code]
[Wed, 19 Feb 2025 16:43:35 virt-install 2174805] DEBUG (cli:256) File
"/usr/bin/virt-install", line 8, in <module>
virtinstall.runcli()
File "/usr/share/virt-manager/virtinst/virtinstall.py", line 1233, in
runcli
sys.exit(main())
File "/usr/share/virt-manager/virtinst/virtinstall.py", line 1226, in main
start_install(guest, installer, options)
File "/usr/share/virt-manager/virtinst/virtinstall.py", line 974, in
start_install
fail(e, do_exit=False)
File "/usr/share/virt-manager/virtinst/cli.py", line 256, in fail
log.debug("".join(traceback.format_stack()))
[Wed, 19 Feb 2025 16:43:35 virt-install 2174805] ERROR (cli:257) internal
error: process exited while connecting to monitor:
2025-02-19T05:43:35.075695Z qemu-system-x86_64: -blockdev
{"driver":"iscsi","portal":"10.1.4.3:3260","target":"iqn.1992-09.com.seagate:01.array.00c0fff6c846-lun-3","lun":0,"transport":"tcp","initiator-name":"iqn.2024-11.localdomain.agbu.agbuvh1:agbu-ldap","node-name":"libvirt-2-storage","auto-read-only":true,"discard":"unmap"}:
iSCSI: Failed to connect to LUN : Failed to log in to target. Status:
Target not found(515)
[Wed, 19 Feb 2025 16:43:35 virt-install 2174805] DEBUG (cli:259)
Traceback (most recent call last):
File "/usr/share/virt-manager/virtinst/virtinstall.py", line 954, in
start_install
domain = installer.start_install(
^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/share/virt-manager/virtinst/install/installer.py", line 695,
in start_install
domain = self._create_guest(
^^^^^^^^^^^^^^^^^^^
File "/usr/share/virt-manager/virtinst/install/installer.py", line 637,
in _create_guest
domain = self.conn.createXML(initial_xml or final_xml, 0)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/usr/lib/python3/dist-packages/libvirt.py", line 4481, in createXML
raise libvirtError('virDomainCreateXML() failed')
libvirt.libvirtError: internal error: process exited while connecting to
monitor: 2025-02-19T05:43:35.075695Z qemu-system-x86_64: -blockdev
{"driver":"iscsi","portal":"10.1.4.3:3260","target":"iqn.1992-09.com.seagate:01.array.00c0fff6c846-lun-3","lun":0,"transport":"tcp","initiator-name":"iqn.2024-11.localdomain.agbu.agbuvh1:agbu-ldap","node-name":"libvirt-2-storage","auto-read-only":true,"discard":"unmap"}:
iSCSI: Failed to connect to LUN : Failed to log in to target. Status:
Target not found(515)
[/code]
Things that could affect the answer
* What I'm calling a SAN is a seagate exos-x iscsi unit
* virtual host is debian 12
* virsh version 9.0.0
* iscsiadm version 2.1.8
1 month
Guest cannot access host HTTP service in NAT
by icefrog1950＠gmail.com
Hi,
I hit a libvirt networking problem that guest cannot access host HTTP service. I debug this issue and tried some efforts. Thanks for your suggestions!
Environment
-------------
guest IP: 192.168.122.46 (Linux, default NAT, installed using virt-manager)
host1 IP: 192.168.3.16 (Centos 8.5 running libvirt and qemu, default libvirt iptable rules)
HTTP service: 192.168.3.16:70 (firewall rules have allowed this port)
host2: 192.168.3.65:70 (for test only)
guest network xml
<interface type="network">
<mac address="52:54:00:f5:a8:9f"/>
<source network="default" portid="6e8ce7e7-6517-43fa-b113-aaddb6c1bc08" bridge="virbr0"/>
<target dev="vnet2"/>
<model type="e1000"/>
<alias name="net0"/>
<address type="pci" domain="0x0000" bus="0x00" slot="0x03" function="0x0"/>
</interface>
1. guest and host1/host2 can ping each other
2. *guest can visit host2 HTTP
3. *guest cannot visit host1 HTTP
When I capture traffic in guest, Wireshark shows:
192.168.122.46 -> 192.168.3.16 // SYN ok
192.168.122.46 <- 192.168.3.16 // Destination unreachable (Port unreachable)
guest route table:
------------------
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.122.1 0.0.0.0 UG 100 0 0 eth0
192.168.122.0 0.0.0.0 255.255.255.0 U 100 0 0 eth0
host1 route table:
------------------
Destination Gateway Genmask Flags Metric Ref Use Iface
0.0.0.0 192.168.3.1 0.0.0.0 UG 100 0 0 enp3s0
192.168.3.0 0.0.0.0 255.255.255.0 U 100 0 0 enp3s0
192.168.122.0 0.0.0.0 255.255.255.0 UG 0 0 0 virbr0
I delete the last rule and add a rule to make sure host1 visits guests will go through 192.168.122.1
------------------
Destination Gateway Genmask Flags Metric Ref Use Iface
(other rules omitted)
192.168.122.0 192.168.122.1 255.255.255.0 UG 0 0 0 virbr0
However, traceroute shows this new rule does not work (which should go to 192.168.122.1 first), and guest cannot visit host1 HTTP request.
[!] guest visit http://192.168.3.16:70 does not go through 192.168.122.1
traceroute 192.168.122.46
traceroute to 192.168.122.46 (192.168.122.46), 30 hops max, 60 byte packets
1 192.168.122.46 (192.168.122.46) 0.200 ms 0.194 ms 0.194 ms
# guest visit http://192.168.3.65:70 goes through 192.168.122.1
traceroute 192.168.3.65
traceroute to 192.168.3.65 (192.168.3.65), 30 hops max, 60 byte packets
1 192.168.122.1 (192.168.122.1) 0.244 ms 0.050 ms 0.120 ms
2 192.168.3.65 (192.168.3.65) 0.823 ms !X 0.802 ms !X 0.789 ms !X
In sum, is there a way to force the guest go through 192.168.122.1 when visiting the hosting machine?
-------------------
libvirt iptable rules:
-P INPUT ACCEPT
-P FORWARD ACCEPT
-P OUTPUT ACCEPT
-N LIBVIRT_INP
-N LIBVIRT_OUT
-N LIBVIRT_FWO
-N LIBVIRT_FWI
-N LIBVIRT_FWX
-A INPUT -j LIBVIRT_INP
-A FORWARD -j LIBVIRT_FWX
-A FORWARD -j LIBVIRT_FWI
-A FORWARD -j LIBVIRT_FWO
-A OUTPUT -j LIBVIRT_OUT
-A LIBVIRT_INP -i virbr0 -p udp -m udp --dport 53 -j ACCEPT
-A LIBVIRT_INP -i virbr0 -p tcp -m tcp --dport 53 -j ACCEPT
-A LIBVIRT_INP -i virbr0 -p udp -m udp --dport 67 -j ACCEPT
-A LIBVIRT_INP -i virbr0 -p tcp -m tcp --dport 67 -j ACCEPT
-A LIBVIRT_OUT -o virbr0 -p udp -m udp --dport 53 -j ACCEPT
-A LIBVIRT_OUT -o virbr0 -p tcp -m tcp --dport 53 -j ACCEPT
-A LIBVIRT_OUT -o virbr0 -p udp -m udp --dport 68 -j ACCEPT
-A LIBVIRT_OUT -o virbr0 -p tcp -m tcp --dport 68 -j ACCEPT
-A LIBVIRT_FWO -s 192.168.122.0/24 -i virbr0 -j ACCEPT
-A LIBVIRT_FWO -i virbr0 -j REJECT --reject-with icmp-port-unreachable # delete this rule does not work
-A LIBVIRT_FWI -d 192.168.122.0/24 -o virbr0 -m conntrack --ctstate RELATED,ESTABLISHED -j ACCEPT
-A LIBVIRT_FWI -o virbr0 -j REJECT --reject-with icmp-port-unreachable # delete this rule does not work
-A LIBVIRT_FWX -i virbr0 -o virbr0 -j ACCEPT
1 month, 1 week