VMware Backup Job Fails – SSL_ERROR_SYSCALL / TLS Handshake Failed on NFC Download (Sporadic, Multiple Customers)

[Woegerbaeur]

Hello everyone,

Case-ID: #08017504

I'm hoping someone here has encountered this issue before. We are experiencing sporadic SSL/TLS handshake errors during backup jobs across multiple VMware environments. The interesting thing is that the job does not ultimately fail the first retry succeeds without any issues. I only noticed this issue in the first place because I monitor the jobs via PRTG, which alerted me to the initial failures. Without that monitoring I likely would have missed it entirely. Still, we would like to understand why the initial attempt fails. The issue does not occur on any of our Hyper-V environments only VMware.I would really appreciate any input or ideas!

Environment:
- Veeam Backup & Replication: v13.0.1.1071
- Hypervisor: Standalone VMware (ESX) – multiple different ESX versions affected
- Affects multiple customers with different configurations
- Different VMs affected each time (not always the same one)

Error Message:
Failed : Error: Can not retrieve requested properties.
Soap fault. SSL_ERROR_SYSCALL
Error observed by underlying SSL/TLS BIO: Unknown error
Detail: 'SSL/TLS handshake failed', endpoint: 'https://[ESXi-HOST-IP]:443/sdk'

Failed to reconnect to storage.
Storage: [stg:[DATASTORE-UUID], nfchost:ha-host, conn:[ESXi-HOST-IP]]
Storage display name: [Daten]

Failed to create NFC download stream.
NFC path: [nfc://conn:[ESXi-HOST-IP],nfchost:ha-host,stg:[DATASTORE-UUID]@[VM-NAME]/[DISK-NAME].vmdk]

Agent failed to process method {Transfer.FileToText}.

Thanks in advance for any help!

[tj818]

Do you see anything in the vCenter/ESXi Logs or have you ran Wireshark/tcpdump? I have come across this in the past and I believe there were some issues on the vCenter side with too many concurrent HTTPS Connections.