From owner-freebsd-stable@freebsd.org Fri Nov 10 15:44:37 2017 Return-Path: Delivered-To: freebsd-stable@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 0A759E7086A for ; Fri, 10 Nov 2017 15:44:37 +0000 (UTC) (envelope-from ruben@verweg.com) Received: from erg.verweg.com (erg.verweg.com [IPv6:2a02:898:96::5e8e:f508]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (Client did not present a certificate) by mx1.freebsd.org (Postfix) with ESMTPS id A19EA78756 for ; Fri, 10 Nov 2017 15:44:36 +0000 (UTC) (envelope-from ruben@verweg.com) Received: from www.verweg.com (www@erg.verweg.com [IPv6:2a02:898:96:0:0:0:5e8e:f508]) by erg.verweg.com (8.15.2/8.15.2) with ESMTP id vAAFiNcw021237 for ; Fri, 10 Nov 2017 15:44:29 GMT (envelope-from ruben@verweg.com) X-Authentication-Warning: erg.verweg.com: Host www@erg.verweg.com [IPv6:2a02:898:96:0:0:0:5e8e:f508] claimed to be www.verweg.com MIME-Version: 1.0 Content-Type: multipart/signed; protocol="application/pgp-signature"; boundary="=_bc8651b7469c654406285b0280c53d05"; micalg=pgp-sha1 Date: Fri, 10 Nov 2017 16:44:22 +0100 From: Ruben van Staveren To: freebsd-stable@freebsd.org Subject: ZFS arc behaviour different after upgrading to 10.4 Organization: Verweg dot Com Message-ID: X-Sender: ruben@verweg.com User-Agent: Roundcube Webmail/1.3.1 X-Spam-Status: No, score=0.0 required=5.0 tests=UNPARSEABLE_RELAY autolearn=unavailable autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on erg.verweg.com X-Greylist: Default is to whitelist mail, not delayed by milter-greylist-4.6.2 (erg.verweg.com [0.0.0.0]); Fri, 10 Nov 2017 15:44:32 +0000 (UTC) X-BeenThere: freebsd-stable@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: Production branch of FreeBSD source code List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Fri, 10 Nov 2017 15:44:37 -0000 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --=_bc8651b7469c654406285b0280c53d05 Content-Transfer-Encoding: 7bit Content-Type: text/plain; charset=US-ASCII; format=flowed Hi list, I noticed that the ZFS ARC is behaving differently with 10.4, giving me a much worser cache effeciency as with 10.3 The following grafana/telefraph graph illustrates this as follows. https://snapshot.raintank.io/dashboard/snapshot/X18wHgmqFnMccEYlnbwgQtYgLIZ4oQLU?panelId=65061&fullscreen&orgId=2 Left I'm still running 10.3, Started some maintenance (binary update with freebsd-update) at 12:36 and booted into 10.4 at 14:34. Since then the ARC hits/misses are much more irregular. Disabling compression (apparently also introduced in 10.4) didn't help that much with regards to the pattern although it did shave off some load of the system. Any thoughts on the changed behaviour? Cheers, Ruben --=_bc8651b7469c654406285b0280c53d05 Content-Type: application/pgp-signature; name=signature.asc Content-Disposition: attachment; filename=signature.asc; size=801 Content-Description: OpenPGP digital signature -----BEGIN PGP SIGNATURE----- iQIcBAEBAgAGBQJaBclWAAoJEIhva+zUd6k/vx4P/AypEQMZagypVQjUoefM3cKg oUDTTJD+VbifuFENNjLo9lCXtaCw/dDKz17K+1ES/QgIdpifIMeGbLuKHjAot644 9waZGrHrz2hcH0FZJDDTGWeX14oOvWc6NuhyTiM+8DyRjz1ubd1mSZzn25RFWiuG R5J2c83ciy1/VeLSh4wsLEYKbu9VsBaZehwOdVcV4tGqqao4ji4dFcqp9Heupu0h Rof7EBOkguaNm/ArrFjqWPig/w2Yys2c7WbXy453zE49Je9LGN3JhjehZb0008JG XrBk3Pyc0FicLDAwTx/4joFVzlFVOBdoI9m5ETfemlaFMMaKG9ci18w7xrZeA7On yQZsgn7yVY/yCAI8hhXQ9TYLnlMLkkTJcsj9avnMCXt6IgRBhHkGJXluNBeV2Ofp sWhwraBeA2ECqbG2JRe1TrhlRk+mw+NgUVw89PI0vcMtlxShQ/tLAxDsO5vBn3GA 971JRDD0SDnByGg1VLLoOODEpIXOh5f+1WciaFHFrPail3Ri7N09hJveFT/bktVv RtZe3LO6x6ICpxVJsKse5xKXYbtp07GgZ2dzNxNC9L7xzEjJPdV529Vp6MFyV15q /BsCvvlZR6g+23mMIbBDzgJdWf9K1dFPHPmCWU3i+rhV4QA8rX7tQGgH6kLCLXO4 l0XyG8Zows/RskkXGNuZ =Yewv -----END PGP SIGNATURE----- --=_bc8651b7469c654406285b0280c53d05--