From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?ISO-8859-1?Q?Fr=E9d=E9ric_VANNI=C8RE?= Subject: Silent data corruption (3.11-rc4) in writethrough mode Date: Mon, 12 Aug 2013 10:22:47 +0200 Message-ID: <52089B57.8000104@planet-work.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: QUOTED-PRINTABLE Return-path: Sender: linux-bcache-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: linux-bcache-u79uwXL29TY76Z2rM5mHXA@public.gmane.org List-Id: linux-bcache@vger.kernel.org Hello, I'm using bcache for Xen hosting. The configuration is : - Servers HP Proliant DL360 G5/G7/Gen8 - Backend : HP Smart Array with 2GB write cache (protected), it's a = partition like /dev/sda2 - Cache device : OWC Mercury Accelsior PCIe (2 x Sandforce in RAID0 = on Marvell 88SE9230), the whole disk like /dev/sdb - Cache mode : writethrough - Kernel : 3.10.5 with bcache driver from 3.11-rc4 - Setup process : make-bcache -B /dev/sda2 ; make-bcache -C /dev/sdb= ; then attached cache device to backend. - LVM setup : pvcreate /dev/bcache0 , vgcreate xen_data /dev/bcache= 0 . Each VM has a LV volume on "xen_data" On some hosts I've noticed very strange behavior with random mysql cras= hes, mysql innodb data corruption, filesystem corruption. I'm running md5 check on system files each night and compares it to deb= ian's database, on some VMs there where modified files (bad MD5). When I detached the cache device, dropped virtualmemory cache on guest = and synced FS, the MD5 of the files where OK again without rebooting. It lookes like bcache had corrupted data in cache, they are no kernel l= ogs on the host, no errors. =46r=E9d=E9ric.