Re: misleading ZFS warning

Ronald Klop <[email protected]> Wed, 22 Jul 2026 17:12:00 +0200 (CEST)
Newsgroups gmane.os.freebsd.devel.file-systems
Message-ID <1285105837.191703.1784733120685@localhost>
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What is underlying pool structure?
Zraid/mirror/single disk?

If zraid, what is the stripesize?

Regards,
Ronald

Van: Anthony Pankov <[email protected]>
Datum: 22 juli 2026 11:51
Aan: [email protected]
Onderwerp: misleading ZFS warning

> 
> 
> Hello,
> 
> Doing this:
> 
>  zfs create  -b 4096 -o volmode=dev  -V 32G as1/dockerim/dsk.adocker
> 
> I've got
> 
> Warning: volblocksize (4096) is less than the default minimum block size (16384).
> To reduce wasted space a volblocksize of 16384 is recommended.
> 
> While ashift=12 for this pool I can't understand am I really do something wrong and there will be "wasted space" or this is a misleading warning.
> 
> Can somebody enlight this?
> 
> -- 
> Best regards,
>  Anthony Pankov                         mailto:[email protected]
> 
> 
> 
> 
> 
> 
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<html><head></head><body>What is underlying pool structure?<div>Zraid/mirror/single disk?</div><div><br></div><div>If zraid, what is the stripesize?</div><div><br></div><div>Regards,</div><div>Ronald</div><div><br></div><div><p><small><strong>Van:</strong> Anthony Pankov &lt;[email protected]&gt;<br><strong>Datum:</strong> 22 juli 2026 11:51<br><strong>Aan:</strong> [email protected]<br><strong>Onderwerp:</strong> misleading ZFS warning<br></small></p><blockquote style="margin-left: 5px; border-left: 3px solid #ccc; margin-right: 0px; padding-left: 5px;"><div class="MessageRFC822Viewer do_not_remove" id="P"><!-- P -->
<!-- processMimeMessage --><div class="TextPlainViewer do_not_remove" id="P.P"><!-- P.P -->Hello,<br>
<br>
Doing this:<br>
<br>
&nbsp;zfs create &nbsp;-b 4096 -o volmode=dev &nbsp;-V 32G as1/dockerim/dsk.adocker<br>
<br>
I've got<br>
<br>
Warning: volblocksize (4096) is less than the default minimum block size (16384).<br>
To reduce wasted space a volblocksize of 16384 is recommended.<br>
<br>
While ashift=12 for this pool I can't understand am I really do something wrong and there will be "wasted space" or this is a misleading warning.<br>
<br>
Can somebody enlight this?<br>
<br>
--&nbsp;<br>
Best regards,<br>
&nbsp;Anthony Pankov &nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;&nbsp;mailto:[email protected]<br>
<br>
<br>
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