Failed to snapshot VM 'xxxxx' during stage: performing backup. High-frequency snapshot failed. Internal error: DPS deltaSync failed (Sync call failed on DPFaultSnapshotTransportFault).

Products

• VMware vSphere ESXi

Issue/Introduction

Following error is seen in VLCR UI 

Failed to snapshot VM 'xxxxx' during stage: performing backup. High-frequency snapshot failed. Internal error: DPS deltaSync failed (Sync call failed on DPFaultSnapshotTransportFault).

/var/run/log/dpd.log (ESXi)

2025-05-29T15:29:43.226Z Er(163) dpd[3794946]: [Originator@6876 sub=VmomiProtectionService opID=0be2aa43-aa4d] Transport provider 
not found for the sync request '(dp.ProtectionService.SyncOp.Spec) {
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    pe = (dp.VirtualMachineProtectedEntity) {
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->       vmRef = 'vim.VirtualMachine:37', 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->       instanceUuid = "5031dae0-5fc5-f4c6-8172-da651dc8f26b", 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    }, 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    syncId = "8d9b914f-3c39-486c-99a6-2356929ceeb0", 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    transportProvider = "com.vmware.vlt", 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    userIds = (dp.VirtualMachineUserIdBinding) {
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->       diskIds = (dp.VirtualMachineUserIdBinding.DiskIdBinding) [
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->          (dp.VirtualMachineUserIdBinding.DiskIdBinding) {
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->             diskKey = 2000, 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->             id = "6000c296-a1f2-6476-1545-f585988b37b6"
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->          }
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->       ]
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    }, 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    synchronizationType = "deltaSync", 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    syncType = "deltaSync", 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    initiatorId = "c3137fecff7c45be86bd995df0cfa94b", 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    snapshotId = "585a7080-884e-4942-aa94-03841113705f", 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    vendorId = "com.vmware.vcdr.dvx.058d69cd-c0cf-4eed-8e34-ae52ebc16edd", 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: --> }'
2025-05-29T15:29:43.226Z Er(163) dpd[3794946]: [Originator@6876 sub=Task opID=0be2aa43-aa4d] Task 'Dp.Task.Sync.b3a8d52a-2cd2-c56b-82a4-27c16de4d375.c3137fecff7c45be86bd995df0cfa94b.585a7080-884e-4942-aa94-03841113705f' failed with error: (dp.fault.SnapshotTransportFault) {
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    faultCause = (vmodl.MethodFault) null, 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    faultMessage = <unset>, 
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    transportProviderResults = <unset>
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: -->    msg = ""
2025-05-29T15:29:43.226Z Er(163) dpd[3794938]: --> }
2025-05-29T15:29:49.220Z In(166) dpd[3795514]: [Originator@6876 sub=Default.HTTPService.HttpConnection] HTTP Connection has timed out while waiting for further requests; <io_obj p:0x00000093f5c14948, h:-1, <UNIX '/var/run/vmware/proxy-dpd'>, <UNIX '/var/run/vmware/proxy-dpd'>>, N7Vmacore16TimeoutExceptionE(Operation timed out: Stream: <io_obj p:0x00000093f5c14948, h:-1, <UNIX '/var/run/vmware/proxy-dpd'>, <UNIX '/var/run/vmware/proxy-dpd'>>, duration: 00:20:01.932236 (hh:mm:ss.us))
2025-05-29T15:29:49.224Z In(166) dpd[3794938]: --> [context]zKq7AVICAgAAAKckdwEMZHBkAAAttFRsaWJ2bWFjb3JlLnNvAACi/TsAd4Q9AOPJRwC+Hz0ASy8sAJQyLAAe2ywA4P8sADtQUgFSeABsaWJwdGhyZWFkLnNvLjAAAj9SD2xpYmMuc28uNgA=[/context]
2025-05-29T15:29:56.529Z Er(163) dpd[3794947]: [Originator@6876 sub=VmomiProtectionService opID=0be2aaa3-aaa8] Transport provider not found for the sync request '(dp.ProtectionService.SyncOp.Spec) {

Environment

VMware Live Cyber Recovery 7.27.5.0

Cause

This is caused if the LWD snapshot call from the ESXi host does reach the VLCR connector for various reasons. 

Resolution

SSH to ESXi hosts

Run below commands to check the status of the deamons 
         /etc/init.d/vltd status 
         /etc/init.d/dpd status 

Run below commands to restart the deamons 
         /etc/init.d/vltd restart
         /etc/init.d/dpd restart