From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mck Subject: Re: Applications using fsync cause hangs for several seconds every few minutes Date: Mon, 18 Jul 2011 17:37:18 +0000 Message-ID: <1311010638.6713.5.camel@localhost> References: Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-D4kxStrZlsNzpQf6+UOq" Cc: linux-btrfs To: Nirbheek Chauhan Return-path: In-Reply-To: List-ID: --=-D4kxStrZlsNzpQf6+UOq Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2011-06-07 at 04:28 +0530, Nirbheek Chauhan wrote: > Every few minutes, (I guess) when applications do fsync (firefox, > xchat, vim, etc), all applications that use fsync() hang for several > seconds, and applications that use general IO suffer extreme > slowdowns. iotop shows various combinations of the processes listed > below doing writes, and the total write as 2-3MB/s.=20 I have experienced this too. It /seemed/ to help removing a lot of snapshots (i have hundreds that i didn't really need). Would it be stupid to try disabling fsync like described at=20 http://ubuntuforums.org/archive/index.php/t-1103926.html ? I don't know of the consequences... but it would prove your theory? ~mck --=20 =E2=80=9CDon=E2=80=99t worry about people stealing your ideas. If your idea= s are any good, you=E2=80=99ll have to ram them down people=E2=80=99s throats.=E2=80= =9D - Howard Aiken=20 | http://semb.wever.org | http://sesat.no | http://tech.finn.no | Java XSS Filter --=-D4kxStrZlsNzpQf6+UOq Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.17 (GNU/Linux) iEYEABECAAYFAk4kb04ACgkQkdPrePiuutOmigCfQBBRXSIstsbUvZ4CXgFAws+m WKgAnj5Ee5+y8lyQP4IXZrTjbM4+BBAx =B6Ko -----END PGP SIGNATURE----- --=-D4kxStrZlsNzpQf6+UOq--