Hi, All I have a cloudstack + xenserver+iscsi cluster with five nodes: node01, node02, node03, node04 and node05.
cloudstack version is 4.11.2 XenServer version is 7.1.2 Primary storage is iSCSI When the newly created VM is assigned to node05, the following errors are prompted in the log: ------------------------------------------------------------------------------------------------------------------- 2019-06-19 21:57:06,826 DEBUG [c.c.a.t.Request] (Work-Job-Executor-28:ctx-f83290e0 job-75093/job-75095 ctx-23f17f03) (logid:687a6387) Seq 3-3381640370201 826942: Executing: { Cmd , MgmtId: 240661250348494, via: 3(node05), Ver: v1, Flags: 100111, [{"org.apache.cloudstack.storage.command.CopyCommand":{"sr cTO":{"org.apache.cloudstack.storage.to.TemplateObjectTO":{"path":"593bfe3a-a161-4b14-a316-c4f6e17094d8","uuid":"7700a9fc-3906-4b24-859c-3ffa4d9b7860","i d":352,"format":"VHD","accountId":2,"hvm":true,"displayText":"yumos 20190301","imageDataStore":{"org.apache.cloudstack.storage.to.PrimaryDataStor eTO":{"uuid":"P01CL01_MIX34","id":61,"poolType":"PreSetup","host":"localhost","path":"/P01CL01_MIX34","port":0,"url":"PreSetup://localhost/P0 1CL01_MIX34/?ROLE=Primary&STOREUUID=P01CL01_MIX34","isManaged":false}},"name":"1e48f683-ad70-4fe7-bb1e-d5731afd4001","size":53687091200,"hypervisorTy pe":"XenServer","bootable":false,"uniqueName":"1e48f683-ad70-4fe7-bb1e-d5731afd4001","directDownload":false}},"destTO":{"org.apache.cloudstack.storage.to .VolumeObjectTO":{"uuid":"2cc60f23-f6f5-447d-8120-f9de61bae6f2","volumeType":"ROOT","dataStore":{"org.apache.cloudstack.storage.to.PrimaryDataStoreTO":{" uuid":"P01CL01_MIX34","id":61,"poolType":"PreSetup","host":"localhost","path":"/P01CL01_MIX34","port":0,"url":"PreSetup://localhost/P01CL01_M IX34/?ROLE=Primary&STOREUUID=P01CL01_MIX34","isManaged":false}},"name":"ROOT-2216","size":53687091200,"volumeId":5333,"vmName":"i-2-2216-VM","account Id":2,"format":"VHD","provisioningType":"THIN","id":5333,"deviceId":0,"hypervisorType":"XenServer"}},"executeInSequence":true,"options":{},"options2":{}, "wait":0}}] } 2019-06-19 21:57:25,836 WARN [c.c.h.x.r.XenServerStorageProcessor] (DirectAgent-133:ctx-5bfa8d07) (logid:687a6387) Unable to create volume; Pool=volumeT O[uuid=2cc60f23-f6f5-447d-8120-f9de61bae6f2|path=null|datastore=PrimaryDataStoreTO[uuid=P01CL01_MIX34|name=null|id=61|pooltype=PreSetup]]; Disk: 2019-06-19 21:57:25,836 DEBUG [c.c.a.m.DirectAgentAttache] (DirectAgent-133:ctx-5bfa8d07) (logid:687a6387) Seq 3-3381640370201826942: Response Received: 2019-06-19 21:57:25,836 DEBUG [c.c.a.t.Request] (DirectAgent-133:ctx-5bfa8d07) (logid:687a6387) Seq 3-3381640370201826942: Processing: { Ans: , MgmtId: 240661250348494, via: 3(node05), Ver: v1, Flags: 110, [{"org.apache.cloudstack.storage.command.CopyCmdAnswer":{"result":false,"details":"There was an S R backend failure.","wait":0}}] } 2019-06-19 21:57:25,836 DEBUG [c.c.a.m.AgentAttache] (DirectAgent-133:ctx-5bfa8d07) (logid:687a6387) Seq 3-3381640370201826942: No more commands found 2019-06-19 21:57:25,836 DEBUG [c.c.a.t.Request] (Work-Job-Executor-28:ctx-f83290e0 job-75093/job-75095 ctx-23f17f03) (logid:687a6387) Seq 3-3381640370201 826942: Received: { Ans: , MgmtId: 240661250348494, via: 3(node05), Ver: v1, Flags: 110, { CopyCmdAnswer } } 2019-06-19 21:57:25,847 WARN [o.a.c.s.d.ObjectInDataStoreManagerImpl] (Work-Job-Executor-28:ctx-f83290e0 job-75093/job-75095 ctx-23f17f03) (logid:687a63 87) Unsupported data object (VOLUME, org.apache.cloudstack.storage.datastore.PrimaryDataStoreImpl@5d4df229), no need to delete from object in store ref t able 2019-06-19 21:57:25,847 DEBUG [o.a.c.e.o.VolumeOrchestrator] (Work-Job-Executor-28:ctx-f83290e0 job-75093/job-75095 ctx-23f17f03) (logid:687a6387) Unable to create Vol[5333|vm=2216|ROOT]:There was an SR backend failure. ---------------------------------------------------------------------------------------------------------------------- Then the VM will be re-created on the other four nodes. VM that has been running normally can be migrated to node 05 through cloudstack online migration. This problem led to my new VM always being created between node1-4. Do you have any suggestions or experiences to share with me? Thank you