Re: makefs -t ffs makes too large image

On Fri, Aug 23, 2024 at 12:39:26AM UTC, Yuri Pankov wrote:
>Anthony Pankov wrote:
>> Hello Miroslav,
>>
>> You are  genius!
>>
>> But the situation is a very frustrating. It is a default system and I did nothing  to turn the compression on.
>> So I was absolutely sure that compression is off.
>>
>> I'm sorry.
>> Nevertheless having compression on by default is a very weird decision and is fully unexpected for me. I've never seen a big warning about default value of this vital parameter will be inverted.
>>
>> On 12 -STABLE:
>>
>>  # zfs get compression
>> NAME                       PROPERTY     VALUE     SOURCE
>> ps2                        compression  off       default
>>
>> On 14-STABLE
>>
>>  # zfs get compression
>> NAME                          PROPERTY     VALUE           SOURCE
>> tank                          compression  on              default
>> tank/bsdsrc                   compression  on              default
>
>It came in with the following openzfs commit and probably no one really
>noticed as installer turns on compression by default, so I was going to
>say it was always that way until I looked up the change :-)
>
>commit 56fa4aa96eb3875f254e93eaef646ea20ba187f9
>Author: Rich Ercolani <rincebrain@gmail.com>
>Date:   Thu Mar 3 13:43:38 2022 -0500
>
>    Default to ON for compression
>
>    A simple change, but so many tests break with it,
>    and those are the majority of this.
>
>    Reviewed-by: George Melikov <mail@gmelikov.ru>
>    Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
>    Signed-off-by: Rich Ercolani <rincebrain@gmail.com>
>    Closes #13078
>
>And it looks like it's in FreeBSD starting with 14.0:
>
>$ git branch -a --contains 56fa4aa96eb3875f254e93eaef646ea20ba187f9
>* main
>  remotes/origin/HEAD -> origin/main
>  remotes/origin/main
>  remotes/origin/pull/956/merge
>  remotes/origin/releng/14.0
>  remotes/origin/releng/14.1
>  remotes/origin/stable/14
>

Hi folks,

      It's maybe also worth mentioning that compression by default makes
      ZFS faster.

      Allan Jude had some numbers for the default (lz4) in the
      presentation he did while implementing zstd[1].

      It can be a bit surprising though, but hopefully it's a good one.;)

Yours,
Daniel Ebdrup Jensen

1: https://papers.freebsd.org/2018/bsdcan/jude-zfs_zstd/