Over-provisioning SSD drives.

[terry5008]

I've noticed that the Bluefin docs discuss over-provisioning using the disk_resize shell command, but the Cobia docs talk about using the CLI command storage disk resize. Yet, the Cobia CLI commands seem to be available in Bluefin. But when the Cobia commands are executed in Bluefin, they run but produce no visible results.

Is the disk resize in the Bluefin CLI a Cobia feature that has no code behind it in Bluefin? Just curious.

Show : TrueNAS Test Bed Specs

AMD EPYC 7502
Supermicro H12SSL-NT motherboard
256GB ECC RAM
SUPERMICRO AOC-S3008L-L8E HBA in IT mode (MB slot #3)
Proxmox 8.0.4
4 2TB Seagate Ironwolf Pro HDDs in a striped mirrored set
2 Kingston 480GB DC600M SSDs mirrored & overprovisioned for SLOG

TrueNAS Test Bed
TrueNAS-SCALE-22.12.3.3 on PVE VM
Allocated 16GB RAM
32GB virtual disk for boot
The AOC-S3008L is passed through to this VM
4 old decommissioned Samsung HDDs connected to AOC-S3008L
3 Samsung PM893 2.5" 960GB SSDs connected to AOC-S3008L

 

[Clauxorr]

Hello. I too am at the point where I'm considering ZIL (SLOG) SSDs and over-provisioning; This is well described in the docs:

SLOG Over-Provisioning

Provides information on the disk_resize command in TrueNAS SCALE.

www.truenas.com

But I also have an M2 NVMe PCIe x16 adapter with 4 NVMe slots on it and 4 NVMes I got for a very good price! and I'm thinking about using some of those for the Log.
So far I have not found references on using NVMes as ZIL (SLOG) and how to over-provision them - those I've read something about being a different process.

Any guidance is appreciated.

Thank you!

 

[Patrick M. Hausen]

Do you have synchronous write access at all? iSCSI or NFS for VMs or databases?

 

[Clauxorr]

Do you have synchronous write access at all? iSCSI or NFS for VMs or databases?

Hello. Thank you for answering.

I am planning to run a VM. I haven't done it before on TrueNAS and I am unsure about the specific settings related to synchronous write access in my environment.

I'm also using the pool I want to attach the Log to for Samba file sharing for at least two Workstations at home. Also, I'm not too sure about the synchronous write access on this one either.

Could be I might not need the ZIL (SLOG) at all? Your question made me wonder about the real utility of it.

 

[Patrick M. Hausen]

SLOG is only useful if there are synchronous writes. For typical SMB share (samba) workloads it is not used at all. Reading your use case I'd recommend creating a dedicated SSD pool for your VM(s).

 

[Clauxorr]

SLOG is only useful if there are synchronous writes. For typical SMB share (samba) workloads it is not used at all. Reading your use case I'd recommend creating a dedicated SSD pool for your VM(s).

This is a precious piece of advice and also an eye-opener on the utility and use of SLOG.

I've also noted the advice on the VM configuration.

Thank you very much for your time. I now know more about the subject.