ZFS, SSD and encryption

[Karl Denninger]

On 7/22/2016 14:02, Eric A. Borisch wrote:
> On Friday, July 22, 2016, Karl Denninger <karl at denninger.net
> <mailto:karl at denninger.net>> wrote:
>
>
>     On 7/22/2016 07:48, Nikos Kastanas wrote:
>     > I have a Lenovo X220 laptop running FreeBSD 10.3-RELEASE with
>     ZFS and
>     > encryption on a plain HDD. I am considering buying a Samsung Pro
>     850 SSD to
>     > boost performance but I am not sure if TRIM and ZFS+Encryption
>     work well
>     > together. After some research online, I found *this page*
>     > <https://www.freebsd.org/doc/faq/all-about-zfs.html>which states the
>     > following:
>     >
>     > *Note: *
>     > ZFS TRIM may not work with all configurations, such as a ZFS
>     filesystem on
>     > a GELI-backed device.
>     >
>     > From what I can understand from the above note, I should not use the
>     > encryption option when installing FreeBSD with ZFS on an SSD.
>     TRIM will not
>     > work correctly and therefore the SSD performace will be impacted.
>     Meh.  Simply not true.  
>
>
> It will not work on 10.3, but will work (as Karl demonstrates) on
> 11.x. Here's the commit to head enabling it:
>
> https://svnweb.freebsd.org/base?view=revision&revision=286444
>
> And here's what is in 10.3 (BIO_DELETE case returns EOPNOTSUPP): 
>
> https://svnweb.freebsd.org/base/releng/10.3/sys/geom/eli/g_eli.c?revision=296373&view=markup#l319
>
>  -  Eric

Note that the system in question (from which the stats were pulled) was
on 10.2 for an extended period of time, with SSDs, and with
Geli-encrypted disks.  It was fine with no performance issues; whether
there is a problem with earlier releases has much to do with the disks
in question.

In the case of the Intel 730s it works perfectly well even though TRIM
is not passed through in that case.

-- 
Karl Denninger
karl at denninger.net <mailto:karl at denninger.net>
/The Market Ticker/
/[S/MIME encrypted email preferred]/
-------------- next part --------------
A non-text attachment was scrubbed...
Name: smime.p7s
Type: application/pkcs7-signature
Size: 2996 bytes
Desc: S/MIME Cryptographic Signature
URL: <http://lists.freebsd.org/pipermail/freebsd-fs/attachments/20160722/65fa5eb1/attachment.bin>