[pve-devel] [PATCH v2 qemu-server 5/9] api: move-disk: add move to other VM
Aaron Lauterer
a.lauterer at proxmox.com
Fri Aug 13 17:35:37 CEST 2021
On 8/13/21 9:41 AM, Fabian Ebner wrote:
> Am 06.08.21 um 15:46 schrieb Aaron Lauterer:
>> The goal of this is to expand the move-disk API endpoint to make it
>> possible to move a disk to another VM. Previously this was only possible
>> with manual intervertion either by renaming the VM disk or by manually
>> adding the disks volid to the config of the other VM.
>>
>> Signed-off-by: Aaron Lauterer <a.lauterer at proxmox.com>
>> ---
>> v1 -> v2:
>> * make --target-disk optional and use source disk key as fallback
>> * use parse_volname instead of custom regex
>> * adapt to find_free_volname
>> * smaller (style) fixes
>>
>> rfc -> v1:
>> * add check if target guest is replicated and fail if the moved volume
>> does not support it
>> * check if source volume has a format suffix and pass it to
>> 'find_free_disk'
>> * fixed some style nits
>>
>> old dedicated api endpoint -> rfc:
>> There are some big changes here. The old [0] dedicated API endpoint is
>> gone and most of its code is now part of move_disk. Error messages have
>> been changed accordingly and sometimes enahnced by adding disk keys and
>> VMIDs where appropriate.
>>
>> Since a move to other guests should be possible for unused disks, we
>> need to check before doing a move to storage to make sure to not
>> handle unused disks.
>>
>> PVE/API2/Qemu.pm | 238 ++++++++++++++++++++++++++++++++++++++++++++++-
>> PVE/CLI/qm.pm | 2 +-
>> 2 files changed, 234 insertions(+), 6 deletions(-)
>>
>> diff --git a/PVE/API2/Qemu.pm b/PVE/API2/Qemu.pm
>> index ef0d877..30e222a 100644
>> --- a/PVE/API2/Qemu.pm
>> +++ b/PVE/API2/Qemu.pm
>> @@ -35,6 +35,7 @@ use PVE::API2::Qemu::Agent;
>> use PVE::VZDump::Plugin;
>> use PVE::DataCenterConfig;
>> use PVE::SSHInfo;
>> +use PVE::Replication;
>> BEGIN {
>> if (!$ENV{PVE_GENERATING_DOCS}) {
>> @@ -3274,9 +3275,11 @@ __PACKAGE__->register_method({
>> method => 'POST',
>> protected => 1,
>> proxyto => 'node',
>> - description => "Move volume to different storage.",
>> + description => "Move volume to different storage or to a different VM.",
>> permissions => {
>> - description => "You need 'VM.Config.Disk' permissions on /vms/{vmid}, and 'Datastore.AllocateSpace' permissions on the storage.",
>> + description => "You need 'VM.Config.Disk' permissions on /vms/{vmid}, " .
>> + "and 'Datastore.AllocateSpace' permissions on the storage. To move ".
>> + "a disk to another VM, you need the permissions on the target VM as well.",
>> check => [ 'and',
>> ['perm', '/vms/{vmid}', [ 'VM.Config.Disk' ]],
>> ['perm', '/storage/{storage}', [ 'Datastore.AllocateSpace' ]],
>> @@ -3287,14 +3290,19 @@ __PACKAGE__->register_method({
>> properties => {
>> node => get_standard_option('pve-node'),
>> vmid => get_standard_option('pve-vmid', { completion => \&PVE::QemuServer::complete_vmid }),
>> + 'target-vmid' => get_standard_option('pve-vmid', {
>> + completion => \&PVE::QemuServer::complete_vmid,
>> + optional => 1,
>> + }),
>> disk => {
>> type => 'string',
>> description => "The disk you want to move.",
>> - enum => [PVE::QemuServer::Drive::valid_drive_names()],
>> + enum => [PVE::QemuServer::Drive::valid_drive_names_with_unused()],
>> },
>> storage => get_standard_option('pve-storage-id', {
>> description => "Target storage.",
>> completion => \&PVE::QemuServer::complete_storage,
>> + optional => 1,
>> }),
>> 'format' => {
>> type => 'string',
>> @@ -3321,6 +3329,20 @@ __PACKAGE__->register_method({
>> minimum => '0',
>> default => 'move limit from datacenter or storage config',
>> },
>> + 'target-disk' => {
>> + type => 'string',
>> + description => "The config key the disk will be moved to on the target VM " .
>> + "(for example, ide0 or scsi1).",
>> + enum => [PVE::QemuServer::Drive::valid_drive_names_with_unused()],
>> + optional => 1,
>
> The default could be mentioned here.
Good point.
>
>> + },
>> + 'target-digest' => {
>> + type => 'string',
>> + description => 'Prevent changes if current configuration file of the target VM has " .
>> + "a different SHA1 digest. This can be used to prevent concurrent modifications.',
>> + maxLength => 40,
>> + optional => 1,
>> + },
>> },
>> },
>> returns => {
>> @@ -3335,14 +3357,22 @@ __PACKAGE__->register_method({
>> my $node = extract_param($param, 'node');
>> my $vmid = extract_param($param, 'vmid');
>> + my $target_vmid = extract_param($param, 'target-vmid');
>> my $digest = extract_param($param, 'digest');
>> + my $target_digest = extract_param($param, 'target-digest');
>> my $disk = extract_param($param, 'disk');
>> + my $target_disk = extract_param($param, 'target-disk') // $disk;
>> my $storeid = extract_param($param, 'storage');
>> my $format = extract_param($param, 'format');
>> + die "either set storage or target-vmid, but not both\n"
>> + if $storeid && $target_vmid;
>> +
>> +
>> my $storecfg = PVE::Storage::config();
>> + my $source_volid;
>> - my $updatefn = sub {
>> + my $move_updatefn = sub {
>> my $conf = PVE::QemuConfig->load_config($vmid);
>> PVE::QemuConfig->check_lock($conf);
>> @@ -3452,7 +3482,205 @@ __PACKAGE__->register_method({
>> return $rpcenv->fork_worker('qmmove', $vmid, $authuser, $realcmd);
>> };
>> - return PVE::QemuConfig->lock_config($vmid, $updatefn);
>> + my $load_and_check_reassign_configs = sub {
>> + my $vmlist = PVE::Cluster::get_vmlist()->{ids};
>> +
>> + if ($vmlist->{$vmid}->{node} ne $vmlist->{$target_vmid}->{node}) {
>> + die "Both VMs need to be on the same node $vmlist->{$vmid}->{node}) ".
>> + "but target VM is on $vmlist->{$target_vmid}->{node}.\n";
>> + }
>> +
>> + my $source_conf = PVE::QemuConfig->load_config($vmid);
>> + PVE::QemuConfig->check_lock($source_conf);
>> + my $target_conf = PVE::QemuConfig->load_config($target_vmid);
>> + PVE::QemuConfig->check_lock($target_conf);
>> +
>> + die "Can't move disks from or to template VMs\n"
>> + if ($source_conf->{template} || $target_conf->{template});
>> +
>> + if ($digest) {
>> + eval { PVE::Tools::assert_if_modified($digest, $source_conf->{digest}) };
>> + if (my $err = $@) {
>> + die "VM ${vmid}: ${err}";
>> + }
>> + }
>> +
>> + if ($target_digest) {
>> + eval { PVE::Tools::assert_if_modified($target_digest, $target_conf->{digest}) };
>> + if (my $err = $@) {
>> + die "VM ${target_vmid}: ${err}";
>> + }
>> + }
>> +
>> + die "Disk '${disk}' for VM '$vmid' does not exist\n"
>> + if !defined($source_conf->{$disk});
>> +
>> + die "Target disk key '${target_disk}' is already in use for VM '$target_vmid'\n"
>> + if exists($target_conf->{$target_disk});
>> +
>> + my $drive = PVE::QemuServer::parse_drive(
>> + $disk,
>> + $source_conf->{$disk},
>> + );
>> + $source_volid = $drive->{file};
>> +
>> + die "disk '${disk}' has no associated volume\n"
>> + if !$source_volid;
>> + die "CD drive contents can't be moved to another VM\n"
>> + if PVE::QemuServer::drive_is_cdrom($drive, 1);
>> + die "Can't move physical disk to another VM\n" if $source_volid =~ m|^/dev/|;
>> + if (PVE::QemuServer::Drive::is_volume_in_use(
>> + $storecfg,
>> + $source_conf,
>> + $disk,
>> + $source_volid,
>> + )) {
>> + die "Can't move disk used by a snapshot to another VM\n"
>> + }
>
> This looks weird to me style-wise. Also missing semicolon after die.
Yeah, no matter how, it either looks weird or will be a few characters over the 100 limit...
For the sake of readability I think I'll opt for the slightly too long post if variant.
>
>> +
>> + if (!PVE::Storage::volume_has_feature(
>> + $storecfg,
>> + 'rename',
>> + $source_volid,
>> + )) {
>> + die "Storage does not support moving of this disk to another VM\n"
>> + }
>
> Same here, but this time the if-condition could fit on one line within the 100 character limit ;) Again, missing semicolon.
You are right, switchting this to post if
>
>> +
>> + die "Cannot move disk to another VM while the source VM is running\n"
>> + if PVE::QemuServer::check_running($vmid) && $disk !~ m/^unused\d+$/;
>> +
>> + if ($target_disk !~ m/^unused\d+$/ && $target_disk =~ m/^([^\d]+)\d+$/) {
>> + my $interface = $1;
>
> Nit: Isn't the interface already present in the result from parse_drive?
The previous parse_drive is done on the source disk. Here we are checking against the target disk which can use a different config key / interface. Also we cannot use parse_drive for the target disk using the source_conf for the data as it will just return undef in case the parse_property_string fails, which is exactly what we are trying to set up here so that we can check if the target disk key supports all config options, and if not, present them to the user, so they have an idea why it does not work.
>
>> + my $desc = PVE::JSONSchema::get_standard_option("pve-qm-${interface}");
>> + eval {
>> + PVE::JSONSchema::parse_property_string(
>> + $desc->{format},
>> + $source_conf->{$disk},
>> + )
>> + };
>> + if (my $err = $@) {
>> + die "Cannot move disk to another VM: ${err}";
>> + }
>> + }
>> +
>> + my $repl_conf = PVE::ReplicationConfig->new();
>> + my $is_replicated = $repl_conf->check_for_existing_jobs($target_vmid, 1);
>> + my ($storeid, undef) = PVE::Storage::parse_volume_id($source_volid);
>> + my $format = (PVE::Storage::parse_volname($storecfg, $source_volid))[6];
>> + if ($is_replicated && !PVE::Storage::storage_can_replicate($storecfg, $storeid, $format)) {
>> + die "Cannot move disk to a replicated VM. Storage does not support replication!\n";
>> + }
>> +
>> + return ($source_conf, $target_conf);
>> + };
>> +
>> + my $logfunc = sub {
>> + my ($msg) = @_;
>> + print STDERR "$msg\n";
>> + };
>> +
>> + my $disk_reassignfn = sub {
>> + return PVE::QemuConfig->lock_config($vmid, sub {
>> + return PVE::QemuConfig->lock_config($target_vmid, sub {
>> + my ($source_conf, $target_conf) = &$load_and_check_reassign_configs();
>> +
>> + my $drive_param = PVE::QemuServer::parse_drive(
>> + $target_disk,
>> + $source_conf->{$disk},
>> + );
>> +
>> + print "moving disk '$disk' from VM '$vmid' to '$target_vmid'\n";
>> + my ($storeid, $source_volname) = PVE::Storage::parse_volume_id($source_volid);
>> +
>> + my (
>> + undef,
>> + undef,
>> + undef,
>> + undef,
>> + undef,
>> + undef,
>> + $fmt
>> + ) = PVE::Storage::parse_volname($storecfg, $source_volid);
>
> Nit: using
> my $fmt = (PVE::Storage::parse_volname($storecfg, $source_volid))[6];
> like above is shorter.
thx!
>
>> +
>> + my $target_volname = PVE::Storage::find_free_volname(
>> + $storecfg,
>> + $storeid,
>> + $target_vmid,
>> + $fmt
>> + );
>> +
>> + my $new_volid = PVE::Storage::rename_volume(
>> + $storecfg,
>> + $source_volid,
>> + $target_volname,
>> + );
>> +
>> + $drive_param->{file} = $new_volid;
>> +
>> + delete $source_conf->{$disk};
>> + print "removing disk '${disk}' from VM '${vmid}' config\n";
>> + PVE::QemuConfig->write_config($vmid, $source_conf);
>> +
>> + my $drive_string = PVE::QemuServer::print_drive($drive_param);
>> + &$update_vm_api(
>> + {
>> + node => $node,
>> + vmid => $target_vmid,
>> + digest => $target_digest,
>> + $target_disk => $drive_string,
>> + },
>> + 1,
>> + );
>> +
>> + # remove possible replication snapshots
>> + if (PVE::Storage::volume_has_feature(
>> + $storecfg,
>> + 'replicate',
>> + $source_volid),
>> + ) {
>> + eval {
>> + PVE::Replication::prepare(
>> + $storecfg,
>> + [$new_volid],
>> + undef,
>> + 1,
>> + undef,
>> + $logfunc,
>> + )
>> + };
>> + if (my $err = $@) {
>> + print "Failed to remove replication snapshots on moved disk " .
>> + "'$target_disk'. Manual cleanup could be necessary.\n";
>> + }
>> + }
>> + });
>> + });
>> + };
>> +
>> + if ($target_vmid) {
>> + $rpcenv->check_vm_perm($authuser, $target_vmid, undef, ['VM.Config.Disk'])
>> + if $authuser ne 'root at pam';
>> +
>> + die "Moving a disk to the same VM is not possible. Did you mean to ".
>> + "move the disk to a different storage?\n"
>> + if $vmid eq $target_vmid;
>> +
>> + &$load_and_check_reassign_configs();
>> + return $rpcenv->fork_worker(
>> + 'qmmove',
>> + "${vmid}-${disk}>${target_vmid}-${target_disk}",
>> + $authuser,
>> + $disk_reassignfn
>> + );
>> + } elsif ($storeid) {
>> + die "cannot move disk '$disk', only configured disks can be moved to another storage\n"
>> + if $disk =~ m/^unused\d+$/;
>> + return PVE::QemuConfig->lock_config($vmid, $move_updatefn);
>> + } else {
>> + die "Provide either a 'storage' to move the disk to a different " .
>> + "storage or 'target-vmid' and 'target-disk' to move the disk " .
>> + "to another VM\n";
>> + }
>> }});
>> my $check_vm_disks_local = sub {
>> diff --git a/PVE/CLI/qm.pm b/PVE/CLI/qm.pm
>> index ef99b6d..a92d301 100755
>> --- a/PVE/CLI/qm.pm
>> +++ b/PVE/CLI/qm.pm
>> @@ -910,7 +910,7 @@ our $cmddef = {
>> resize => [ "PVE::API2::Qemu", 'resize_vm', ['vmid', 'disk', 'size'], { node => $nodename } ],
>> - 'move-disk' => [ "PVE::API2::Qemu", 'move_vm_disk', ['vmid', 'disk', 'storage'], { node => $nodename }, $upid_exit ],
>> + 'move-disk' => [ "PVE::API2::Qemu", 'move_vm_disk', ['vmid', 'disk', 'storage', 'target-vmid', 'target-disk'], { node => $nodename }, $upid_exit ],
>> move_disk => { alias => 'move-disk' },
>> unlink => [ "PVE::API2::Qemu", 'unlink', ['vmid'], { node => $nodename } ],
>>
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