Running FreeBSD on M.2 SSD

[Chris]

On Fri, 28 Feb 2020 21:44:45 -0300 Mario Olofo mario.olofo at gmail.com said

> Hello guys, a little update that let me more confused
> 
> I reinstalled the FreeBSD with 4k pages using the sysctl
> vfs.zfs.min_auto_ashift = 12 and no errors after a lot of stress I put on
> it.
> One thing that I noticed is that with the pool as 4k, the disk fill up very
> fast, recompiling the kernel used my 8GB space and didn't even completed.
> But now I don't know if the 4k is the correct answer or if this just delays
> the problem as the pages are bigger.
The TLDR of 4k vs 512 largely has to do with the size of the files going
onto your medium. Many files of a smaller size fit better on a 512 boundary.
Whereas larger mp3s or archives fair better on a 4k boundary. BTW these are
called SECTOR sizes. Not pages. :) 4k blocks typically read faster, than the
512 blocks (sectors). Because more data can be consumed in one read/write.
So really, your going to have to decide how best to "tune" your disk to best
suite it's intended use. Many small files. Or big files, and storage.

HTH

--Chris
FreeBSD 14.0-FUTURE #0.000 cray256
> 
> Mario
> 
> Em sex., 28 de fev. de 2020 às 13:18, Mario Olofo <mario.olofo at gmail.com>
> escreveu:
> 
> > Yes, tried 4k quirk but not on install because don't know how to, I did a
> > clean install then patch and rebuild the kernel, but
> > the volume was already configured for 512bytes, I think I would need to
> > create manually the volume, but don't remember how to anymore xD
> > But I'll search some tutorials and try. From what I saw, the patch
> > suggested on bugzilla got merged into the stable branch, so the quirk will
> > be
> > detected to use 4k in the installer in a near future.
> >
> > Mario
> >
> > Em sex., 28 de fev. de 2020 às 12:52, Theron <theron.tarigo at gmail.com>
> > escreveu:
> >
> >> On 2020-02-28 09:14, Mario Olofo wrote:
> >> > Thanks!
> >> >
> >> > The only thing that I didn't checked was the questions of Theron, about
> >> > misaligned data.
> >> > The layout of the disk is as follows:
> >> >
> >> > Disco /dev/sdb: 447,1 GiB, 480113590272 bytes, 937721856 setores
> >> > Unidades: setor de 1 * 512 = 512 bytes
> >> > Tamanho de setor (lógico/físico): 512 bytes / 512 bytes
> >> > Tamanho E/S (mínimo/ótimo): 512 bytes / 512 bytes
> >> > Tipo de rótulo do disco: gpt
> >> > Identificador do disco: D1725E60-D734-4461-90F8-E9EB2376A65A
> >> >
> >> > Dispositivo    Início       Fim   Setores Tamanho Tipo
> >> > /dev/sdb1        2048   1023999   1021952    499M Windows ambiente de
> >> > recuperação
> >> > /dev/sdb2     1024000   1228799    204800    100M Sistema EFI
> >> > /dev/sdb3     1228800   1261567     32768     16M Microsoft reservado
> >> > /dev/sdb4     1261568 532482047 531220480  253,3G Microsoft dados básico
> >> > /dev/sdb5   532482048 549257215  16775168      8G FreeBSD ZFS
> >> > /dev/sdb6   549257216 937719807 388462592  185,2G Linux sistema de
> >> arquivos
> >> >
> >> > The zfsroot was configured automatically by the installer, so I think
> >> that
> >> > it align the volume automaticaly right?
> >> >
> >> > Mario
> >>
> >> Yes, I don't see any potential alignment issue here.  I would wonder if
> >> this drive is misrepresenting its physical sector size, deceiving ZFS
> >> and the SATA driver into making small writes that the drive does not
> >> actually support, but it looks like you may have already tried the
> >> relevant workaround:
> >>
> >> On 2020-02-27 23:44, Mario Olofo wrote:
> >> > Maybe the problem really is a combination of factors, for the person
> >> that
> >> > filed a bug on bugzilla the fix was setting the quirks 4k and
> >> broken_trim,
> >> > but for me the real block size is 512bytes and only setting the flag
> >> > broken_trim didn't help...
> >> >
> >> > Mario
> >> Did you try 4k quirk ?
> >>
> >> Theron
> >>
> >
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