For NVMe SSDs, use native 4K (4096-byte) sectors if possible

[probonopd]

For NVMe disks, we should use native 4K (4096-byte) sectors ("Advanced 4Kn Format") if possible; this gives a ~10% performance enhancement.

It seems that by default NVMe SSDs in FreeBSD are running in 512-byte sectors, which is not ideal:

Users-Laptop% sudo diskinfo -v /dev/nvme0ns1

/dev/nvme0ns1
        512             # sectorsize
        256060514304    # mediasize in bytes (238G)
        500118192       # mediasize in sectors
        0               # stripesize
        0               # stripeoffset
        No              # TRIM/UNMAP support
        Unknown         # Rotation rate in RPM

This is for a Transcend PCIe SSD 220S, which "aims at high-end applications, such as digital audio/video production, gaming, and enterprise use".

How can we know whether a SSD supports native 4K sectors? The data sheet doesn't specify sector size.

smartctl output ("SMART" in Hardware Probe) shows:

Supported LBA Sizes (NSID 0x1)
Id Fmt  Data  Metadt  Rel_Perf
 0 +     512       0         0

Does this mean that this SSD will not support 4Kn?

In case it did supoprt 4Kn, would we have to

sudo pkg install nvme-cli
nvmecontrol format --lbaf=1 /dev/XXX
zpool create -o ashift=12 ...

?

And how to tell bsdinstall to do "the right thing"?

NOTE: ashift=12 means that the pool is configured to use a 4K (4096-byte) sector size. In ZFS terminology, this is sometimes referred to as "ashift 12" or "4K alignment."

Why is all of this not happening automatically?

More information:

• Bits inside by René Rebe: You DO NOT use your NVME SSDs to their BEST PERFORMANCE: THIS is the SIMPLE FIX!

[probonopd]

Interestingly, on FreeBSD 14.0-RC4 I get with a Samsung SSD 980 PRO:

% sudo smartctl /dev/nda0
smartctl 7.4 2023-08-01 r5530 [FreeBSD 14.0-RC4 amd64] (local build)
Copyright (C) 2002-23, Bruce Allen, Christian Franke, www.smartmontools.org

Smartctl open device: /dev/nda0 failed: INQUIRY failed

and

% sudo diskinfo -v /dev/nvme0ns1
/dev/nvme0ns1
        512             # sectorsize
        1000204886016   # mediasize in bytes (932G)
        1953525168      # mediasize in sectors
        0               # stripesize
        0               # stripeoffset
        No              # TRIM/UNMAP support
        Unknown         # Rotation rate in RPM

Why does it think it doesn't support TRIM?

[svmhdvn]

@probonopd try running smartctl /dev/nvme0 instead