Data Domain over NFS and Access TIme Issues

[vnick_coty]

I'm trying to mount a DD9800 over NFS to a PBS server so that I can use it for backups. I'm running into an issue when trying to configure this - as posted in several other places, when trying to initialize a datastore that is NFS-mounted, I get the following at the end of the process:

2026-08-20T10:12:36-04:00: Chunkstore create: 99%
2026-08-20T10:12:39-04:00: Chunk metadata was not correctly updated during access time safety check:
2026-08-20T10:12:39-04:00: Timestamps before update: accessed Some(SystemTime { tv_sec: 1787235162, tv_nsec: 40857000 }), modified Some(SystemTime { tv_sec: 1787235162, tv_nsec: 40857000 }), created Some(SystemTime { tv_sec: 1787235162, tv_nsec: 35616000 })
2026-08-20T10:12:39-04:00: Timestamps after update: accessed Some(SystemTime { tv_sec: 1787235162, tv_nsec: 40857000 }), modified Some(SystemTime { tv_sec: 1787235162, tv_nsec: 40857000 }), created Some(SystemTime { tv_sec: 1787235162, tv_nsec: 35616000 })
2026-08-20T10:12:39-04:00: TASK ERROR: access time safety check failed: access time safety check using newly inserted chunk failed, aborting GC!

Reading the other threads, it seems that PBS relies on the access time for garbage collection functionality (if I understood correctly), and that the solution is usually to make sure that whatever server is providing the NFS server has access time enabled. Unfortunately, I cannot figure out how to do this on the Data Domain.

Wondering if anyone else has accomplished this on the Data Domain, or if there are any work-arounds for it?

 

[bbgeek17]

Unfortunately, I cannot figure out how to do this on the Data Domain.

I don't think there is a way to do this, but Dell/EMC/DD is the best source to ask this question.

Wondering if anyone else has accomplished this on the Data Domain, or if there are any work-arounds for it?

The check was added as a bumper against accidentally GC what is being in use. You can disable it but then you risk running into the original issue of what the bump was created to prevent.

The workaround is described here:
https://pbs.proxmox.com/docs/storage.html#:~:text=gc-atime-safety,the default value.

Or don't run GC

---

Blockbridge : Ultra low latency all-NVME shared storage for Proxmox - https://www.blockbridge.com/proxmox

 

[vnick_coty]

I don't think there is a way to do this, but Dell/EMC/DD is the best source to ask this question.

Yeah, I'm also hunting around Dell for this answer, too, just figured I'd tackle multiple possible scenarios.

The check was added as a bumper against accidentally GC what is being in use. You can disable it but then you risk running into the original issue of what the bump was created to prevent.

The workaround is described here:
https://pbs.proxmox.com/docs/storage.html#:~:text=gc-atime-safety,the default value.

Or don't run GC

Thanks for that hint, I'll take a look and maybe at least give it a try.