From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stefan Priebe - Profihost AG Subject: Re: ont out of 6 bcache devices does not register automatically Date: Thu, 23 Nov 2017 08:10:06 +0100 Message-ID: <03029ee8-2856-19a3-a44d-8fbdc3f27da4@profihost.ag> References: <3ebfa7f8-cef6-ca8f-a56f-14a6bafd5bc6@profihost.ag> <22a61b57-1fbf-5ec4-383c-13b2cb8eaaf2@coly.li> <5c8958c1-acfd-14c9-d29f-0726ca92bc1c@profihost.ag> <58151524-1294-2c8a-42a0-a5f21886625d@coly.li> <6c624629-c528-fd92-420f-ea50c4e6e4c5@profihost.ag> <93a1e381-ea82-b5c0-444b-6bdd3062e7f0@profihost.ag> <73e9184b-c74b-fe92-bb87-a0b945931187@lyle.org> <91e9b95d-861e-13bb-2b61-5c010657c2af@profihost.ag> <864cbf6d-7e8d-7dd4-7417-3150fe019fd8@lyle.org> <3fde77da-e12f-7862-f3c5-2a3dad316b86@profihost.ag> <0387447a-cce1-4162-3458-03193e146732@lyle.org> <0ab9bd3f-f2ea-04d7-1416-941b3d93d410@profihost.ag> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 7bit Return-path: Received: from cloud1-vm154.de-nserver.de ([178.250.10.56]:43641 "EHLO cloud1-vm154.de-nserver.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750880AbdKWHKI (ORCPT ); Thu, 23 Nov 2017 02:10:08 -0500 In-Reply-To: Content-Language: de-DE Sender: linux-bcache-owner@vger.kernel.org List-Id: linux-bcache@vger.kernel.org To: Michael Lyle , Coly Li Cc: "linux-bcache@vger.kernel.org" , n.fahldieck@profihost.ag Hello, i got it... first of all the same issue still applies to util-linux v2.31 which is the latest upstream version. # ./blkid --version lt-blkid from util-linux 2.31 (libblkid 2.31.0, 19-Oct-2017) # ./blkid -o udev -p /dev/sdf1 ID_FS_AMBIVALENT=other:bcache other:xfs_external_log The issue is somewhat different. The device is used for ceph which stores on on that Disk 4MB slices of VM block devices. So we have: bcache => XFS on top => thousands of files containing VM images => XFS in those images So the xfs_external_log superblock which is seen by blkid is in reality a superblock of a VM image inside a file which is saved in bcache. This make even more sense as the system was bootable without any problems for the last few years without swapping a disk. But somewhat now a VM image file has exactly positioned it's superblock on a position blkid expects a superblock. I see no way to solve it except for changing the udev rules file which comes with bcache-tools. Instead of only checking: ENV{ID_FS_TYPE}=="bcache", GOTO="bcache_backing_found" it also needs to check for: ID_FS_AMBIVALENT=other:bcache Any opinions or suggestions? Greets, Stefan Am 22.11.2017 um 22:13 schrieb Stefan Priebe - Profihost AG: > > Am 22.11.2017 um 22:10 schrieb Michael Lyle: >> On 11/22/2017 01:07 PM, Stefan Priebe - Profihost AG wrote: >>> default debian jessie version: >>> # blkid -v >>> blkid from util-linux 2.25.2 (libblkid 2.25.0, 24-Oct-2014) >> >> OK, so it's ancient. >> >> One other thing that can get you-- if there was ever an xfs or other >> filesystem on this disk -without- bcache, then you created bcache & xfs >> on it without wipefs... the old superblock can still be hanging around >> and not having happened to been rewritten. > > no there shouldn't eb ever an xfs without it on disk - but i can't > guarantee that. > > To reproduce the isue you need the first 10MB of the disk. > > See below: > > Still ok: > > # dd if=/dev/sdf1 of=/tmp/8k bs=8M count=1 > 1+0 records in > 1+0 records out > 8388608 bytes (8,4 MB) copied, 0,01318 s, 636 MB/s > # /sbin/blkid -o udev -p /tmp/8k > ID_FS_UUID=65811163-4ffc-4823-ad72-bae10ce85b63 > ID_FS_UUID_ENC=65811163-4ffc-4823-ad72-bae10ce85b63 > ID_FS_TYPE=bcache > ID_FS_USAGE=other > > not anymore: > > # dd if=/dev/sdf1 of=/tmp/8k bs=10M count=1 > 1+0 records in > 1+0 records out > 10485760 bytes (10 MB) copied, 0,0115798 s, 906 MB/s > # /sbin/blkid -o udev -p /tmp/8k > ID_FS_AMBIVALENT=other:bcache other:xfs_external_log > > Stefan > >> >> Mike >> >>> >>>> >>>> Mike >>>> -- >>>> To unsubscribe from this list: send the line "unsubscribe linux-bcache" in >>>> the body of a message to majordomo@vger.kernel.org >>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>>> >>> -- >>> To unsubscribe from this list: send the line "unsubscribe linux-bcache" in >>> the body of a message to majordomo@vger.kernel.org >>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>> >>