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Date: Sun, 20 Jan 2013 17:45:31 -0500
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Subject: ZFS _receiving_ TRIM ? (unmap)
From: Zaphod Beeblebrox <zbeeble@gmail.com>
To: freebsd-fs <freebsd-fs@freebsd.org>
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So... I see that using TRIM is a scheduled feature for ZFS.  This is good
--- ZFS's policy of never overwriting active data make's it's use of TRIM
all the more important.

But I'm concerned about the other side.  If I have an iSCSI disk exported
from ZFS, will ZFS receive the "UNMAP" (SCSI's TRIM) and free those blocks?