Date: Tue, 13 Dec 2016 06:54:46 +0000 From: =?utf-8?B?S2FybGkgU2rDtmJlcmc=?= <karli.sjoberg@slu.se> To: javocado <javocado@gmail.com> Cc: "freebsd-questions@freebsd.org" <freebsd-questions@freebsd.org>, "freebsd-virtualization@freebsd.org" <freebsd-virtualization@freebsd.org>, FreeBSD Filesystems <freebsd-fs@freebsd.org> Subject: Re: Re-sparse a file-backed IO device + zfs Message-ID: <fa5f1d106a6b4a21ad408b30e8b14ffa@exch2-4.slu.se>
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Den 13 dec. 2016 02:20 skrev javocado <javocado@gmail.com>: > > Hi, > > I'm setting up a bhyve wherein: > > host # truncate -s 1T vol.file > host # du -ah vol.file > 200K vol.file > > host # /usr/sbin/bhyve ... -s 4,ahci-hd,vol.file ... > > Then inside the bhyve I create a zpool (ada0 = vol.file): > > bhyve # zpool create -O devices=off -O atime=off -O compression=on -m > /mnt/data1 data1 ada0 > > And I put a bunch of stuff in the zpool ... and the vol.file grows in size: > > host # du -ah vol.file > 100G vol.file > > Then I remove the files from the zpool and the zpool usage returns to 0 but > of course the vol.file size does not shrink, the data is still there (but > not referenced?) > > Normally I'd just write zeros to a file inside the zpool until the pool > fills up, then maybe cp --sparse vol.file for good measure, but with > compression on in the zpool the zeroing doesn't really fill up space or > seem to overwrite anything. In my testing the zero file grew larger than > 100G with no change to vol.file I did not let it run forever, however. > > Any other ideas how to scrub off or clear out deleted data from a zpool > and/or this kind of file-backed device? Wouldn't you have needed TRIM on the disk(s) inside the VM and it would have taken care of all this for you? /K > _______________________________________________ > freebsd-fs@freebsd.org mailing list > https://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org"
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