From mboxrd@z Thu Jan 1 00:00:00 1970 From: bugzilla-daemon@bugzilla.kernel.org Subject: [Bug 110441] New: KVM guests randomly get I/O errors on VirtIO based devices Date: Wed, 06 Jan 2016 17:06:24 +0000 Message-ID: Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit To: kvm@vger.kernel.org Return-path: Received: from mail.kernel.org ([198.145.29.136]:53183 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751572AbcAFRGa (ORCPT ); Wed, 6 Jan 2016 12:06:30 -0500 Received: from mail.kernel.org (localhost [127.0.0.1]) by mail.kernel.org (Postfix) with ESMTP id 8A9F22014A for ; Wed, 6 Jan 2016 17:06:28 +0000 (UTC) Received: from bugzilla2.web.kernel.org (bugzilla2.web.kernel.org [172.20.200.52]) by mail.kernel.org (Postfix) with ESMTP id 092912013A for ; Wed, 6 Jan 2016 17:06:25 +0000 (UTC) Sender: kvm-owner@vger.kernel.org List-ID: https://bugzilla.kernel.org/show_bug.cgi?id=110441 Bug ID: 110441 Summary: KVM guests randomly get I/O errors on VirtIO based devices Product: Virtualization Version: unspecified Kernel Version: 3.16.7-ckt11-1+deb8u5 Hardware: All OS: Linux Tree: Mainline Status: NEW Severity: normal Priority: P1 Component: kvm Assignee: virtualization_kvm@kernel-bugs.osdl.org Reporter: jordi.mallach@collabora.co.uk Regression: No We've been seeing a strange bug in KVM guests hosted by a Debian jessie box (running 3.16.7-ckt11-1+deb8u5 on x86-64), Basically, we are getting random VirtIO errors inside our guests, resulting in stuff like this [4735406.568235] blk_update_request: I/O error, dev vda, sector 142339584 [4735406.572008] EXT4-fs warning (device dm-0): ext4_end_bio:317: I/O error -5 writing to inode 1184437 (offset 0 size 208896 starting block 17729472) [4735406.572008] Buffer I/O error on device dm-0, logical block 17729472 [ ... ] [4735406.572008] Buffer I/O error on device dm-0, logical block 17729481 [4735406.643486] blk_update_request: I/O error, dev vda, sector 142356480 [ ... ] [4735406.748456] blk_update_request: I/O error, dev vda, sector 38587480 [4735411.020309] Buffer I/O error on dev dm-0, logical block 12640808, lost sync page write [4735411.055184] Aborting journal on device dm-0-8. [4735411.056148] Buffer I/O error on dev dm-0, logical block 12615680, lost sync page write [4735411.057626] JBD2: Error -5 detected when updating journal superblock for dm-0-8. [4735411.057936] Buffer I/O error on dev dm-0, logical block 0, lost sync page write [4735411.057946] EXT4-fs error (device dm-0): ext4_journal_check_start:56: Detected aborted journal [4735411.057948] EXT4-fs (dm-0): Remounting filesystem read-only [4735411.057949] EXT4-fs (dm-0): previous I/O error to superblock detected (From an Ubuntu 15.04 guest, EXT4 on LVM2) Or, Jan 06 03:39:11 titanium kernel: end_request: I/O error, dev vda, sector 1592467904 Jan 06 03:39:11 titanium kernel: EXT4-fs warning (device vda3): ext4_end_bio:317: I/O error -5 writing to inode 31169653 (offset 0 size 0 starting block 199058492) Jan 06 03:39:11 titanium kernel: Buffer I/O error on device vda3, logical block 198899256 [...] Jan 06 03:39:12 titanium kernel: Aborting journal on device vda3-8. Jan 06 03:39:12 titanium kernel: Buffer I/O error on device vda3, logical block 99647488 (From a Debian jessie guest, EXT4 directly on a VirtIO-based block device) When this happens, it affects multiple guests on the hosts at the same time. Normally they are severe enough that they end up with a r/o file system, but we've seen a few hosts survive with a non-fatal I/O error. The host's dmesg has nothing interesting to see. We've seen this happen with quite heterogeneous guests: Debian 6, 7 and 8 (Debian kernels 2.6.32, 3.2 and 3.16) Ubuntu 14.09 and 15.04 (Ubuntu kernels) 32 bit and 64 bit installs. In short, we haven't seen a clear characteristic in any guest, other than the affected hosts being the ones with some sustained I/O load (build machines, cgit servers, PostgreSQL RDBMs...). Most of the times, hosts that just sit there doing nothing with their disks are not affected. The host is a stock Debian jessie install that manages libvirt-based QEMU guests. All the guests have their block devices using virtio drivers, some of them on spinning media based on LSI RAID (was a 3ware card before, got replaced as we were very suspicious about it, but are getting the same results), and some of them based on PCIe SSD storage. We have some other 3 hosts, similar setup except they run Debian wheezy (and honestly we're not too keen on upgrading them yet, just in case), none of them has ever shown this kind of problem We've been seeing this since last summer, and haven't found a pattern that tells us where these I/O error bugs are coming from. Google isn't revealing other people with a similar problem, and we're finding that quite surprising as our setup is quite basic. This has also been reported downstream at the Debian BTS as Bug#810121 (https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=810121). -- You are receiving this mail because: You are watching the assignee of the bug.