From mboxrd@z Thu Jan 1 00:00:00 1970 From: Loic Dachary Subject: partprobe or partx or ... ? Date: Sat, 19 Sep 2015 17:23:36 +0200 Message-ID: <55FD7DF8.7060601@dachary.org> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="Fhg3BrkXgnK54gX4XNOo3ouCrQecsQOHB" Return-path: Received: from mail2.dachary.org ([91.121.57.175]:57972 "EHLO smtp.dmail.dachary.org" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754712AbbISPXi (ORCPT ); Sat, 19 Sep 2015 11:23:38 -0400 Sender: ceph-devel-owner@vger.kernel.org List-ID: To: Ilya Dryomov Cc: Ceph Development This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --Fhg3BrkXgnK54gX4XNOo3ouCrQecsQOHB Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Hi Ilya, At present ceph-disk uses partprobe to ensure the kernel is aware of the = latest partition changes after a new one is created, or after zapping the= partition table. Although it works reliably (in the sense that the kerne= l is indeed aware of the desired partition layout), it goes as far as to = remove all partition devices of the current kernel table, only to re-add = them with the new partition table. The delay it implies is not an issue b= ecause ceph-disk is rarely called. It however generate many udev events (= dozens remove/change/add for a two partition disk) and almost always crea= tes border cases that are difficult to figure out and debug. While it is = a good way to ensure that ceph-disk is idempotent and immune to race cond= itions, maybe it is needlessly hard. Do you know of a light weight alternative to partprobe ? In the past we'v= e used partx but I remember it failed to address some border cases in non= -intuitive ways. Do you know of another, simpler, approach to this ? Thanks in advance for your help :-) --=20 Lo=C3=AFc Dachary, Artisan Logiciel Libre --Fhg3BrkXgnK54gX4XNOo3ouCrQecsQOHB Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (GNU/Linux) iEYEARECAAYFAlX9ffgACgkQ8dLMyEl6F201lACgjzp7NZ8Rn59g9izaMuuMmt6W d94An2qY6ClDbt/YUJ4pr8hNT9Yh01ub =1PMt -----END PGP SIGNATURE----- --Fhg3BrkXgnK54gX4XNOo3ouCrQecsQOHB--