TrueNAS 12 4kn disks

[Fred.]

Hi,

I'm new to TrueNAS and I have some WD drives that should be capable to convert to 4k sectors.
I want to do the right thing to get the best performance and avoid emulation.
This is what I see with smartctl.
From what I understand it's seeing the drive as 4k but is using 512k sectors on it? That's not good then? For best performance that should be the same?
There is no data on the disks / pool so I can still convert things. Just not sure how.
Does that look good or bad to you?

Code:

smartctl -i /dev/da22                     
smartctl 7.1 2019-12-30 r5022 [FreeBSD 12.2-RC3 amd64] (local build)
Copyright (C) 2002-19, Bruce Allen, Christian Franke, www.smartmontools.org

=== START OF INFORMATION SECTION ===
Vendor:               WDC
Product:              WUH721818AL5204
Revision:             C120
Compliance:           SPC-5
User Capacity:        18,000,207,937,536 bytes [18.0 TB]
Logical block size:   512 bytes
Physical block size:  4096 bytes

Code:

zdb -U /data/zfs/zpool.cache | grep ashift
            ashift: 12

Thanks
Fred.

 

[AlexGG]

From what I understand it's seeing the drive as 4k but is using 512k sectors on it? That's not good then? For best performance that should be the same?

There will be no practically noticeable difference in performance as long as your writes are multiples of 4096 bytes in size and properly aligned. Your pool seems to satisfy both criteria, so it should be fine.

 

[Fred.]

Thanks for your answer Alex.
So this is optimal and you would not change it?

I would like to test the diffenence with my workload.
Do you know if it's easy to change?

 

[AlexGG]

I don't think it is reasonably possible to change the 512-byte logical block size on the drive, although I may be mistaken.
You can change your pool block size by setting ashift to 9, which gives you 512 bytes per allocation unit on the pool, by destroying and recreating the pool. On the drive, though, I don't think it is possible.

 

[Patrick M. Hausen]

FreeBSD and FreeNAS have a default ashift of 12 for some time now. Precisely for the proliferation of 4k disks. The disk presenting a logical block size of 512 for backwards compatibility is normal.

 

[Fred.]

Ok, Thanks everyone.
I will leave it as is then.

 

[diskdiddler]

FreeBSD and FreeNAS have a default ashift of 12 for some time now. Precisely for the proliferation of 4k disks. The disk presenting a logical block size of 512 for backwards compatibility is normal.

Patrick I trust your opinion, what do you think about this?

How to convert 512e to 4Kn using Fast Format (Seagate Exos X16 drive) ?

thanks for this info. it helped me out. nothing much to add, but i'll share my X18 experience. i have some exos 18TB X18 SATA drives (model: ST18000NM000J). go here https://apps1.seagate.com/downloads/request.html put your serial(s) and download the fw update package. in my case it was for...

www.truenas.com

Should people bother or not bother flipping to 4k? What's the implications?
One fella reporting 2 dead drives due to it, others reporting the Exos has issues with idle power states?

 

[Patrick M. Hausen]

My statement was of course of a general nature. I cannot say anything about that particular drive model and the effects of running it with 512e or native 4k, sorry. I'd check with the manufacturer.