Adam Litke has uploaded a new change for review.
Change subject: LiveMerge: Add liveMerge capability to vdsCaps
......................................................................
LiveMerge: Add liveMerge capability to vdsCaps
It is desirable for engine to know up front if a host can support live
merge so the UI can either enable or disable the 'Delete' snapshot
command based on presence of the feature.
Change-Id: Iac66c679166b5687ed3940e517fe6827fe10e258
Signed-off-by: Adam Litke <ali...@redhat.com>
---
M vdsm/caps.py
M vdsm/rpc/vdsmapi-schema.json
M vdsm/virt/vm.py
3 files changed, 32 insertions(+), 7 deletions(-)
git pull ssh://gerrit.ovirt.org:29418/vdsm refs/changes/98/28998/1
diff --git a/vdsm/caps.py b/vdsm/caps.py
index 68851c9..e8c4844 100644
--- a/vdsm/caps.py
+++ b/vdsm/caps.py
@@ -246,6 +246,26 @@
@utils.memoized
+def getLiveMergeSupport():
+ """
+ Determine if libvirt provides the necessary features to enable live merge.
+ We check for the existence of several libvirt flags to serve as indicators:
+
+ VIR_DOMAIN_BLOCK_COMMIT_RELATIVE indicates that libvirt can maintain
+ relative backing file path names when rewriting a backing chain.
+
+ VIR_DOMAIN_EVENT_ID_BLOCK_JOB_2 indicates that libvirt can pass a drive
+ name (ie. vda) rather than a path to the block job event callback.
+ """
+ for flag in ('VIR_DOMAIN_BLOCK_COMMIT_RELATIVE',
+ 'VIR_DOMAIN_EVENT_ID_BLOCK_JOB_2'):
+ if not hasattr(libvirt, flag):
+ logging.debug("libvirt is missing '%s': live merge disabled", flag)
+ return False
+ return True
+
+
+@utils.memoized
def getNumaTopology():
capabilities = _getCapsXMLStr()
caps = minidom.parseString(capabilities)
@@ -609,6 +629,7 @@
liveSnapSupported = _getLiveSnapshotSupport(targetArch)
if liveSnapSupported is not None:
caps['liveSnapshot'] = str(liveSnapSupported).lower()
+ caps['liveMerge'] = str(getLiveMergeSupport()).lower()
caps['kdumpStatus'] = _getKdumpStatus()
return caps
diff --git a/vdsm/rpc/vdsmapi-schema.json b/vdsm/rpc/vdsmapi-schema.json
index 2ccf963..486a7cb 100644
--- a/vdsm/rpc/vdsmapi-schema.json
+++ b/vdsm/rpc/vdsmapi-schema.json
@@ -1155,6 +1155,11 @@
# @kdumpStatus: The current status of kdump configuration for the host:
# enabled (1), disabled(0), unknown(-1)
# (new in version 4.15.0)
+#
+# @liveMerge: #optional Indicates if live merge is supported on this
+# host.
+# (new in version 4.15.0)
+#
# Since: 4.15.0
#
# Notes: Since ovirt-engine cannot parse software versions in 'x.y.z' format,
@@ -1179,7 +1184,7 @@
'numaNodeDistance': 'NumaNodeDistanceMap',
'autoNumaBalancing': 'AutoNumaBalancingStatus',
'selinux': 'SELinuxStatus', '*liveSnapshot': 'bool',
- 'kdumpStatus': 'int'}}
+ 'kdumpStatus': 'int', '*liveMerge': 'bool'}}
##
# @Host.getCapabilities:
diff --git a/vdsm/virt/vm.py b/vdsm/virt/vm.py
index abdd9b0..216d2a7 100644
--- a/vdsm/virt/vm.py
+++ b/vdsm/virt/vm.py
@@ -5476,6 +5476,10 @@
return jobs
def merge(self, driveSpec, baseVolUUID, topVolUUID, bandwidth, jobUUID):
+ if not caps.getLiveMergeSupport():
+ self.log.error("Live merge is not supported on this host")
+ return errCode['mergeErr']
+
bandwidth = int(bandwidth)
if jobUUID is None:
jobUUID = str(uuid.uuid4())
@@ -5519,12 +5523,7 @@
# Indicate that we expect libvirt to maintain the relative paths of
# backing files. This is necessary to ensure that a volume chain is
# visible from any host even if the mountpoint is different.
- try:
- flags = libvirt.VIR_DOMAIN_BLOCK_COMMIT_RELATIVE
- except AttributeError:
- self.log.error("Libvirt missing VIR_DOMAIN_BLOCK_COMMIT_RELATIVE. "
- "Unable to perform live merge.")
- return errCode['mergeErr']
+ flags = libvirt.VIR_DOMAIN_BLOCK_COMMIT_RELATIVE
if topVolUUID == drive.volumeID:
# Pass a flag to libvirt to indicate that we expect a two phase
--
To view, visit http://gerrit.ovirt.org/28998
To unsubscribe, visit http://gerrit.ovirt.org/settings
Gerrit-MessageType: newchange
Gerrit-Change-Id: Iac66c679166b5687ed3940e517fe6827fe10e258
Gerrit-PatchSet: 1
Gerrit-Project: vdsm
Gerrit-Branch: master
Gerrit-Owner: Adam Litke <ali...@redhat.com>
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