A disk-only snapshot was taken without any space check, though its
overlays grow as the guest writes and a later delete merges them down;
a full pool pauses the guest and can leave the snapshot undeletable.
Only a memory snapshot was checked, for the memory alone.
Before a snapshot, each storage pool with a disk of the VM must have
free a share of those disks' virtual size (10%, at least 1 GiB), and
the pool of the memory file the VM's memory on top. Both values are on
the Settings page (Snapshot Free Percent, Snapshot Free Min GiB; 0
turns a rule off, an invalid value keeps the default). The pools are
refreshed first, and a failed refresh or an unreadable volume refuses
the snapshot instead of skipping the check; a disk in no pool is not
checked. Nothing is reserved: later writes can still fill a pool.
A disk-only snapshot of a running VM is crash-consistent: data the
guest has not written yet is missing from it. With a connected QEMU
guest agent, the snapshot form now offers to freeze the guest's file
systems while the disks are snapshotted (libvirt's QUIESCE flag); the
box is checked by default and can be cleared. It is offered only for a
running VM whose agent is connected, and not together with memory:
libvirt accepts quiesce only for disk-only snapshots, and a memory
snapshot keeps the whole guest state anyway. A request that does not
fit is refused before libvirt is called.
Reverting a running or paused VM to a disk-only external snapshot
powers it off: libvirt starts it again from the snapshot's disks, as
after a power cut. The confirmation now says so for such a snapshot; a
snapshot with memory resumes the VM as it was saved.
After a snapshot revert or delete, files libvirt could not remove are
named in a warning that says nothing uses them and asks to remove them
by hand. A file another VM on the same host uses (as a disk, a backing
file or a snapshot file) is no longer named: removing it would break
that VM. The warning now says no VM on this host uses the files.
libvirt deletes any volume it is asked to. The storage page and the API
deleted a VM's disk, the base image of another volume or the file a
snapshot was taken on without a check, breaking the VM or its
snapshots.
wvmStorage.del_volume now refuses a volume a domain on the compute uses
as a disk or a backing file of one, a file of a domain's snapshots, or
the backing file of another volume. The check is the one destroy
already used, moved to wvmConnect and extended to snapshot files, so
destroy also keeps the files of another VM's snapshots. The storage
page shows the refusal; the API answers 400 with it, as for other
refusals. Deleting a disk from a VM refuses after the detach when the
VM's own snapshots need the volume, and says the volume was kept.
Network disks count by their source name, pool volume disks by their
volume's path. A volume whose metadata cannot be read stops the check
instead of counting as unused; only one removed meanwhile is skipped.
The check and the delete hold the compute lock, so no VM operation
attaches the volume in between; a busy compute is a message on the page
and 409 in the API.
Deleting a VM with its data deleted only the images its disks pointed
at. With external snapshots that is the newest overlay: the image the
snapshots were taken on, the older overlays and the memory files stayed
on disk, with nothing referring to them once the VM and its snapshot
metadata were gone.
The files the VM's snapshots were taken on, down each disk's backing
chain, the overlays of snapshots kept off the chain after a revert, and
the snapshots' memory files are now the VM's own too. A template the
VM grew from ends the chain and stays, as does an overlay of a disk
detached since. The backing references of the VM's own volumes no
longer count as another domain's use, and a file another VM uses keeps
the files below it.
A backing file that cannot be read (other than one in no pool) stops the
split before anything is deleted, instead of ending the chain there.
The snapshot tab listed the VM's snapshots three times per page: once
per kind and once more for all of them. The list of all is now made
from the two kinds, so the combined flag is no longer used anywhere.
The revert confirm named only the disks the persistent definition
would lose. A disk hot-plugged into the running VM alone is detached
too, so the live definition is compared with what ran when the
snapshot was taken.
A storage pool refresh error after libvirt had already made, reverted
or deleted the snapshot was shown as if the operation had failed. It
is now logged, and the left-behind check is skipped then, since a stale
pool still lists the removed files. A volume removed while that check
reads it is skipped too.
An error reading the block jobs no longer breaks the instance page;
create, revert and delete still query the jobs again and refuse.
When libvirt cannot remove a snapshot file it merged or discarded, it
only logs a warning and the delete or revert still succeeds. On NFS it
removes them as the qemu user, so an image directory the qemu user may
not write to left every merged overlay on disk without a word.
Revert and delete now compare the files in use before and after and
show a warning naming the ones still on disk. Only a snapshot's own
files (overlays, memory) and overlays on a snapshot point count, and a
disk the revert detached is never named, so a kept disk is not offered
for removal.
Create, revert and delete are one libvirt call each. The pflash-to-rom
loader rewrite, the hand-written block commit and the s1./s2. names are
gone, so UEFI VMs can take external snapshots, a revert keeps disks added
later, and deleting an older snapshot keeps the newer one.
Create refuses what libvirt could not revert or delete later: internal
snapshots on the VM, a saved state, a running snapshot job, disks that
are not files, CD-ROM media, a branch after a revert, and memory without
a running VM or room in the first disk's pool. A disk-only revert keeps
the VM running, paused or shut off; one with memory resumes it as saved.
A revert in the same second as the previous one, which libvirt fails
after stopping the VM, is retried once.
A snapshot the old code took of a UEFI VM saved the loader as rom; its
revert is refused (deleting it still works).
The snapshots tab lists internal and external snapshots separately, can
save memory too, shows running snapshot jobs, and the revert confirmation
names the disks it detaches and that NVRAM is not restored.
131 test modules sat next to the code they test; instances alone had
51 of them beside views.py and utils.py. They move into a
tests/ package per app, and the JavaScript checks into
webvirtcloud/tests/js. Each non-empty tests.py becomes tests/test_views.py;
the empty generated stubs are removed.
Imports of the app's own modules become absolute, paths built from
__file__ go one level up, the live helper is instances.tests.livetest,
and coverage omits */tests/*. The suite discovers the same 960 tests as
before.
On an active VM a device was attached in two calls, running VM first.
When the persistent attach was refused, for example because a disk target
or an agent channel was already pending there, the device stayed in the
running VM only and was gone at the next start. A NIC added without a
MAC got a different generated MAC in each definition. One call with
AFFECT_LIVE|AFFECT_CONFIG lets QEMU check the persistent copy before the
hotplug and keeps one MAC. Detach and update still go per definition,
each from its own XML.
The device name of a new disk or CD-ROM was chosen from the running VM
only. A name used only in the persistent definition, such as a disk
renamed by a pending bus change, could be chosen again: the disk was
attached to the running VM, the persistent attach was refused, and the
disk was gone after the next start. Names either definition uses are now
taken.
On an active VM the boot order editor, the video model select and the
console form showed the running VM: a pending boot order, video model or
console setting looked unset, and the boot order editor offered devices
of the running VM only. Choosing one of those cleared the pending order,
since the setter dropped the old order and skipped devices it could not
find. They now read the persistent definition (get_bootmenu,
get_bootorder, get_media_devices, get_video_model and the console
getters take config=), and set_bootorder refuses a device that is not in
it before it changes anything.
On an active VM the options and CPU forms write the persistent definition
but showed the running VM's title, description and vCPUs, so saving one
posted the live values back over a pending change. They now read the
persistent definition (get_vcpu, get_cur_vcpu, get_title and
get_description take config=).
Buttons in the settings and resize tabs that were disabled only by class
get the disabled attribute: Enter in a field no longer submits a form
the page shows as unavailable while the VM runs.
The QoS table showed the running VM's bandwidth while an edit changes the
definition for the next start. Each row posts average, peak and burst,
so an edit wrote the running values back over a pending change, and a
direction added while the VM ran had no row. The table shows the
persistent definition now. An edit also kept only the posted values and
dropped an inbound floor; it now updates them and keeps the rest.
On a running VM a disk edit changes the definition for the next start,
but the disk list and its edit form showed the running VM's disks. The
form posts every field, so an edit wrote the running values back over
earlier pending changes (cache, io, serial, ...), and a disk only in the
next definition could not be edited. The list now shows the persistent
disks. A volume is deleted only when both definitions use it at that
device, since the list may now show another source than the running VM.
The CPU bar showed the average since the host booted, read for every
compute on every load of the VM list. The dialog now reads each compute's
graph endpoint (load over one second) when it opens, two computes at a
time so the reads hold at most two workers, and ignores answers of an
earlier opening. A host that cannot be read shows a dash. The since-boot
reading had no other caller and is removed.
Enabling hot plug on a stopped VM wrote every vCPU up to the maximum as
enabled, so a VM with 2 of 4 vCPUs booted with 4. The current vCPUs stay
enabled now; libvirt adds the rest as disabled hotpluggable vCPUs.
Only a running VM counted as active, so a paused one (or one blocked,
PM-suspended or shutting down) had its maximum and current memory written
for the next boot and nothing applied live. Every active VM now has its
current memory changed live and in its definition and keeps its maximum;
a paused guest takes the new size once resumed. The quota check follows
the same rule. Checked on a real guest: paused, shrunk, resumed, then
grown back.
The .vv console file is built from the VM found by its UUID, with the
console page's getters, instead of looking the VM up by name five times;
a console without a listen address or password now gives 127.0.0.1 and
an empty password instead of "None". Removed methods nothing calls: the
by-name getters and power methods of wvmInstances, managed save, the vCPU
mode getter (it read the wrong attribute), the old NIC editor and its
bridge lookup. CD-ROM media and NIC hotplug use _definitions() like the
other device edits, the disk editor takes the bus prefix from
util.vol_dev_type, and an unreadable disk is logged, not printed.
Cloning a UEFI VM defined a persistent storage pool on the NVRAM's
directory when no pool held it, and dropped <nvram> from the clone,
which found its copy only because libvirt chose the same file name.
The copy is now made through the NVRAM directory's pool (a transient one
when there is none) or the pool that holds the file, with the original's
format, owner and mode, and the clone's definition names it. A failed
definition removes it with the copied disks. An NVRAM that is not a file
is refused before anything is copied.
A volume of an LVM or iSCSI pool can be attached: by its own path, with
the format its volume reports (raw when the pool knows none). Detaching
a disk takes each definition's own description of it, so a disk only in
the persistent definition goes too. Every NIC type can be a boot device;
bridge and direct NICs were dropped from the boot order. The video model
is a value, never parsed as XML. QoS changes clear the page's read cache.
The NIC model "default" leaves the choice to libvirt instead of writing
model "default", and rt18139 is rtl8139: a VM with either did not start
(checked on a RHEL 10 host). A migration corrects the default NIC type
setting.
Each stats answer carries a signed sample of the counters, bound to the VM,
its compute and UUID. The next poll sends it back and the rates are the
averages since then; a sample from another run of the VM (domain ID),
another host CPU count or device list, or older than 30 s falls back to
one second as before. Windows are measured on the monotonic clock.
Now that a poll is cheap, the Stats tab polls every 5 s like the host
graph, the first time as soon as it opens (pollWhileVisible takes the
delay of the first request).
A counter the host reports as unsupported (-1) or that went back gives no
value instead of 0 or a jump; a NIC without a target keeps its chart, a
pool volume disk is measured, and a disk or NIC attached after the page
loaded no longer stops the other charts. Disk rates are MB/s (they were
MiB/s labelled Mb/s), network Mbit/s; the CPU tooltip names the window.
Measured on a VM with two disks, a CD-ROM and a NIC: 70 libvirt calls per
page, now 43. Within the page's cached_reads block the VM's state, the
host's info and domain capabilities, and each disk path's volume are read
once; the running and the persistent disk lists share a path's volume.
The ISO list takes the active pools in one call instead of looking each up
by name; it still refreshes them, so an image copied in by hand shows up.
The opt-in DRBD status waits at most 10 s for the compute's ssh, then
leaves the status unknown instead of holding the page.
Destroy deletes the NVRAM file only when asked (VIR_DOMAIN_UNDEFINE_NVRAM,
otherwise KEEP_NVRAM): a unit test checks the flags, live tests check the
file on the host both ways. A VM whose disk is an overlay with a snapshot
goes with its own image and the snapshot metadata, and the base image
stays, since other images may grow from it.
libvirt undefines the source domain after a migration but keeps its NVRAM
file. A VM created later on that host with the same name reuses the file
and starts with the old VM's UEFI variables (boot entries, enrolled keys):
checked on libvirt 11.10, where only VIR_DOMAIN_START_RESET_NVRAM
recreates it from the template.
After a successful migration the file is now deleted on the source, as a
volume of the pool on libvirt's NVRAM directory or of a transient one.
Only a file in /var/lib/libvirt/qemu/nvram, and only when the destination
cannot create a marker file the source just created there (an exclusive
create also fails on shared storage whose listing an NFS client caches).
A failed removal is logged with the migration, which stands and is
recorded.
The resize tab enabled disk growth only for a shut-off VM, although
resize_disk already grows a running domain's disk through blockResize.
The button is now enabled for running and paused VMs too. A live test
grows qcow2 and raw disks of a running and of a paused VM and checks the
size the guest sees, the volume size, the unchanged persistent definition
and the state.
A VM that disappears from its compute keeps its owners in a tombstone
until INSTANCE_OWNERSHIP_RETENTION_DAYS pass, but nothing showed them.
Superusers now see them on the "Removed VMs" admin page (name, UUID,
owners, removed, expires) and can remove one, so a VM deleted on
purpose no longer hands its owners to a later VM with the same UUID.
Files that libguestfs creates have no SELinux label. On an enforcing
guest (RHEL, Rocky, Alma, Fedora) sshd may not read the unlabeled
/root/.ssh/authorized_keys, so a key added from the panel did not let
anyone log in ("avc: denied { read } ... unlabeled_t").
After writing a key, gstfsd now relabels /root/.ssh with the guest's own
file contexts (/etc/selinux/<SELINUXTYPE>/contexts/files/file_contexts),
as virt-customize does. Guests without an SELinux policy or with SELinux
disabled are left as they are. If the guest needs labels but the host's
libguestfs cannot set them, the request fails before anything is written.
A root password needs no labelling: /etc/shadow keeps its file and label.
A clone copies the disks of the VM's persistent definition, but its disk
quota and the disk names chosen with automatic naming came from the
running VM's disks, which differ after a disk is attached or detached on
the running VM only.
The Destroy button was disabled and the confirmation page refused a
paused VM ("Instance is suspended, cannot destroy!"), while the destroy
request itself stops a paused VM like a running one. Both now offer it.
Without instances.snapshot_instances (snapshots) or is_vnc (console
settings) the request was accepted and silently did nothing, although
the documented answer for a missing right is 403. delete_external_snapshot
also asked libvirt for the VM state before checking the permission.
Redirects to #access (root password, SSH key) and other top-level panes
opened nothing, and some sub-tab ids did not exist. static/js/instance_tabs.js
opens the pane and the tab that holds it from the page structure, and
opens Settings on its first section, without leaving the current tab;
guest OS info is loaded whenever it is the section opened. The bottom bar linked to
host pages, which only administrators may open, and showed host names to
everyone. A stray </li> is removed; the page's inline scripts and the tab
logic are checked with Node.
Power cycle force-stopped and started a template, which power on refuses.
A non-staff owner with is_delete could delete a template that the
template rule otherwise leaves to superusers and staff owners;
get_instance(perm_type="delete") now refuses it, and the page offers
Destroy by the same rule.
A VM operation (or destroy and clone, which hold the whole compute) waits
for its compute's lock while a migration holds it. When the migration
moved the VM's record to the destination, the waiting operation went on
there holding only the source compute's lock, unordered with a
reconciliation, migration or disk attach on the destination. After taking
the locks it now checks the VM is still on the locked compute and
otherwise answers busy, so the retry locks the right one. Clone also
checks again under the lock whether the user may clone the VM, and
checks the quota and the clone's settings against the VM as it is then:
its template mark, size or the user's rights may have changed meanwhile.
gstfsd mounted every partition it listed: a root on LVM was never found,
a disk with two OS roots got the change twice and two concatenated
replies, and no root, an error or a request longer than 1024 bytes ended
the connection without a reply. It now lets libguestfs inspect the guest,
mounts its one OS the way the guest does (a broken filesystem off the
changed path is left out), and sends exactly one reply, keeping the first
error. The root entry is found on any line of /etc/shadow and must be
unique; a key needs no shadow file. A request is at most 64 KiB. Each
change runs in a worker process with a directly started appliance; both
are killed when the request is not done 100 s after gstfsd accepted it
(GSTFSD_DEADLINE may only lower that), before the panel's 120 s timeout
releases the VM, or when the panel's connection ends, and the reply waits
until they are gone, so nothing touches the disk once the panel has given
up. A worker that dies says why. The panel
connects over IPv4 or IPv6, sends the whole request and reads the reply
until gstfsd closes.
The documented rule held only for snapshots: an owner with is_change could
still resize a template, set its root password and SSH keys, change its
options and console settings. get_instance(perm_type="change") now
refuses a template to owners who are not staff, which covers every change
view and the API; the per-view snapshot checks it replaces are removed,
and the page offers those controls by the same rule. Viewing, the console,
power (a no-op on a template) and cloning are unchanged.
The page showed controls the backend then refused: power to global
viewers, the console, virt-viewer and VDI controls and the root password
and SSH key forms to viewers, resize to staff, per-vCPU hotplug, video
model and guest agent to non-superusers, clone and options by the clone
permission alone, snapshots without change permission. The page now asks
the views' own rules (owner, is_change, clone and snapshot permissions,
the template rules). OS info, opened from the header, is there for every
viewer; the XML editor and tab restoring after a redirect no longer throw
when a pane is absent; Settings opens on the first section the user has.
The authorization matrix also covers a template VM, the template clone
rule and the template snapshot rule.
Several instance mutation views crashed with a bare HTTP 500 when a form field
the UI always sends was absent or malformed (a direct or crafted request);
ExceptionMiddleware turns only libvirt and timeout errors into 4xx, so these
reached a 500. Fixed:
- add_network parsed a None network source ("'NoneType' has no attribute
'split'"); it now requires a selected network.
- set_qos read an unbound local 'mac' when no field name contained "mac", and
passed an invalid direction or non-numeric rate to the proxy (ValueError); it
now requires a MAC, an inbound/outbound direction and whole-number rates.
- unset_qos passed an empty direction into the proxy's XPath (XPathEvalError);
it now requires a MAC and a valid direction.
- resizevm_cpu and resize_memory ran int() over an empty or non-numeric value;
they now validate with int() (not str.isdigit(), which accepts "²" that
int() rejects).
- add_public_key passed a missing/non-numeric sshkeyid into an integer-id
lookup (ValueError); it now requires a numeric id.
Each reports the problem and returns to the VM page without calling libvirt or
logging, as change_network already does.
Tests: each view with a field missing, non-numeric or a unicode digit returns
302 with an error message, writes no log, and does not attempt the mutation.
The tests fail on the previous code.
A compute's hostname and login go unquoted into the libvirt connection URI
(qemu+ssh://login@host/system, qemu+tcp://host/system, qemu+tls://...) and,
for an SSH compute, into the ssh command line of the DRBD status view. They
were barely validated: validate_hostname used re.match with a negated class,
so it caught only a leading special character, and login was never checked.
A hostname like "192.0.2.1/system?command=/path" injected a libvirt URI
parameter (verified: connecting ran the named command through the ssh
wrapper), and TLS/SSH parameters such as no_verify, pkipath, socket or
netcat could be added the same way; a login like "-oProxyCommand=..." became
an ssh option. The DRF ComputeSerializer applied neither check, and
validate_name tested a string literal instead of its argument, so it never
raised.
validate_hostname now accepts only an IPv4 address or a host name with
fullmatch (no scheme, port, path, query, whitespace or IPv6 literal; IPv6 is
left out until the URI building brackets it). validate_login accepts an empty
value (TCP falls back to the server's authentication, the socket transport
ignores the login) or a plain name with no leading "-". Both sit on the
Compute model fields, so the forms and the DRF serializer (which copies model
validators onto its fields) reject the values; a migration records the
metadata. validate_name checks its argument. drbd_status validates the login
and hostname before building login@host and ends ssh option parsing with
"--"; an existing or bypassed bad row is skipped rather than run.
Tests: hostname/login validators accept real values and reject URI and
option injection; the SSH form and the serializer (create, and an empty TCP
login) enforce them; drbd_status skips an injecting target. Checked the real
test computes still validate. The new tests fail on the previous code.
A VM that changes its memory faster than the network carries it does
not finish a live migration without auto converge (measured: a guest
rewriting about 1.2 GB/s did not finish in 90 s over an 8.5 Gbit/s
link, and finished in 16-18 s with it). Auto converge only slows the
VM's CPUs while the migration cannot keep up, so a calm VM is not
affected.
The migrate form ticks it for a running VM. The API already documented
it as on by default but read a left-out option as off; the serializer
now has the defaults (auto converge on, compress and unsafe off) for
JSON and form-encoded requests, and the schema shows them.
A VM that changes its memory faster than the network carries it never
finishes a live migration without auto converge: measured with a guest
rewriting about 1.2 GB/s over an 8.5 Gbit/s link. The migration then
ran until gunicorn ended the request after 600 s. libvirt cancelled it
when the request went away and the VM stayed on the source, but the
user got an error page and nothing was logged.
The app now cancels a migration that has not finished after 540 s
(MIGRATION_TIME_LIMIT, below the 600 s of gunicorn.conf.py; a test
keeps it below). The failure is reported and logged like any other:
the migration was cancelled, the VM stays on the source host, and a
VM like that needs auto converge. A timer that fires as the migration
ends finishes before the compute locks are released, and an error
the cancel did not cause keeps its own message.
With "VM Clone Auto Migrate" on, a new clone was migrated to a random
compute, whatever storage, CPU or network that host had, and a failed
migration showed as a failed clone although the clone existed.
The setting and its code are removed; migration appsettings.0015
deletes the setting. A clone can be migrated afterwards like any VM.
The README's update notes list the migration changes: the migration
address, storage pools for the disk check, and this setting.
What migrate_instance did around the migration itself:
- It checked the destination with a 1 s TCP probe of the libvirt port,
which passes while libvirt is down or refuses the login. It now uses
the compute's connection status, as the rest of the app does.
- Two requests for the same VM waited for the compute locks one after
the other; the second then migrated with the VM's old location. The
VM's record is read again under the locks, and the request is
refused when the VM is no longer on the source.
- Restoring autostart on the destination came after the migration but
before the database move; when it failed, the VM ran on the
destination while the app recorded it on the source. Autostart is
now read from libvirt and a failure to restore it is only logged.
- A database failure after a successful migration was logged as
nothing; the log now says the VM migrated and recording it failed.
- When the destination's list had already made a record for the VM,
the merge kept the owners but dropped the template mark.
moveto read the VM state for each flag and dropped options that did
not fit it, so a request could run as something else than asked; the
log then named the mode from the form ("live" or "offline"), not the
one used. The API did not log at all and answered "instance migrate is
started" after the migration had finished.
- moveto reads the state once. A running VM migrates live, or without
live paused for the transfer (non-live); a paused VM stays paused; a
shut-off VM moves offline. Live for a shut-off VM, offline for a
running or paused one, and any other state are refused before
anything changes. unsafe, auto converge (live only) and compressed
apply to a running VM.
- migrate_instance logs the outcome for the VM page and the API: the
mode and options used, or the error. The API answers
"instance is migrated (<mode>)" and accepts requests that leave out
an optional option.
- Post copy is gone from the form, the view and the API: only the
flag was set, and without migrateStartPostCopy, which the app never
called, the migration never switched to post copy.
Migration is client-driven: libvirt sends the VM's memory to the
destination's own host name unless a migration URI is given, and the
app never gave one. Where the hosts cannot resolve each other's names
(or the names point at a management network) every migration failed
with "Unable to resolve address '<host name>' service '49152'".
A compute now has an optional migration address (an IP address or a
host name, no scheme or port), editable in the compute form and the
API. A VM migrating to that compute is sent to tcp://<address>
(bracketed for IPv6). Empty, the default for existing computes, keeps
the previous behavior. The compute's host name is not reused, because
for SSH computes it can be an ssh_config alias.
The migration log entry names the address when one is set.
