Date: Mon, 3 Aug 2020 17:12:09 -0400 From: Charles Sprickman <spork@bway.net> To: Allan Jude <allanjude@freebsd.org> Cc: freebsd-fs@freebsd.org Subject: Re: zfs scrub enable by default Message-ID: <0E22A84A-DAAF-4651-865B-0AE038C7C3F4@bway.net> In-Reply-To: <24edb075-155c-439d-1ef5-541893036429@freebsd.org> References: <cca34d1a-1892-41ec-ce45-84865100c6e1@FreeBSD.org> <24edb075-155c-439d-1ef5-541893036429@freebsd.org>
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--Apple-Mail=_71218212-C9A8-468D-BD83-5DA65A9CB9FD Content-Transfer-Encoding: quoted-printable Content-Type: text/plain; charset=utf-8 > On Aug 3, 2020, at 4:25 PM, Allan Jude <allanjude@freebsd.org> wrote: >=20 > On 2020-08-03 12:10, Steve Wills wrote: >> Hi, >>=20 >> I wonder why we don't enable zfs periodic scrub by default? >>=20 >> = https://svnweb.freebsd.org/base/head/usr.sbin/periodic/periodic.conf?view=3D= markup#l162 >>=20 >>=20 >> Anyone happen to know? >>=20 >> Thanks, >> Steve >>=20 >> _______________________________________________ >> 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" >=20 > I think switching this to on-by-default is a good thing. >=20 > To be clear, which the check is part of 'periodic daily', it only > triggers a scrub if it has been more than 35 days since the last = scrub. >=20 > FreeNAS already has does this, and that accounts for a large number of > FreeBSD ZFS deployments. >=20 > There is tuning you can do in ZFS to try to lessen the impact of a = scrub > on your production workloads. >=20 >=20 > The periodic script lets you select which pools to include (defaults = to > all), so you can tune it to only scrub your root pool every 35 days, = and > not the large pool that might take too long to scrub or whatever. It > also lets you set a different threshold for each pool. >=20 > So I don't see any reason not to enable it by default, and just = document > how to adjust it if people really need to disable it. Honestly, I = think > those who are disabling it are doing themselves a disservice. I 100% agree. I think often FreeBSD defaults tend to favor the = experienced user and throw the newbies under the bus. In this case there = were arguments against that amounted to =E2=80=9CWhat about people = running large production systems=E2=80=9D, to which my answer would be, = =E2=80=9CWhat about them? They are experienced, read all the mailing = lists, would know right away what was happening when they saw a scrub = running, and already know how to disable it and could make the case for = disabling or swapping in their own solution=E2=80=9D. Contrast with the random home user, noob, casual user who would likely = benefit from whatever data protection, pre-emptive failure notification, = etc. this would provide (for example I=E2=80=99ve had a scrub show me a = failing drive before SMART did). Charles >=20 > -- > Allan Jude >=20 --Apple-Mail=_71218212-C9A8-468D-BD83-5DA65A9CB9FD Content-Transfer-Encoding: 7bit Content-Disposition: attachment; filename=signature.asc Content-Type: application/pgp-signature; name=signature.asc Content-Description: Message signed with OpenPGP -----BEGIN PGP SIGNATURE----- Comment: GPGTools - http://gpgtools.org iQEzBAEBCAAdFiEECbwhUg0jlYPK5QaKiZUhnP6GpPYFAl8ofakACgkQiZUhnP6G pPbhfwgAsVMetrmx5pgpt4V0oRElZffcMtUdvSYh5gWEW6vESu+rBdScR2tqEXwG pjlmhg9rZBnRdHKWe4NZQ3S7GHTSnr4jK60tkpoVzy4zdPNiFOkl1MKOsyZzQPfC 6fGT1bfEfcMPKA5QrwGU6hJ4PoB7XnLPeFwZ91Ilp+tnj9odfSo0tbAAjHCWe+rR mgN1Ey5MGOnhNw3ey+cn6YKqffGYsns32dwTaLnV77yRFkQS1Tj+DMnkpFfTQf43 CocG1ooPnr7+1LrtR26qzy8yWF1fyxxwDbP/MGXsfvIv/cHKJuD30KxXT1Q2qDND xOno5tnFtlNLBLIs9EakWFXv0uHTfQ== =yjDH -----END PGP SIGNATURE----- --Apple-Mail=_71218212-C9A8-468D-BD83-5DA65A9CB9FD--
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