From mboxrd@z Thu Jan 1 00:00:00 1970 From: Michael Tokarev Subject: the >1Tb block issue Date: Tue, 18 May 2010 19:52:45 +0400 Message-ID: <4BF2B7CD.7090204@msgid.tls.msk.ru> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit To: KVM list Return-path: Received: from isrv.corpit.ru ([81.13.33.159]:42095 "EHLO isrv.corpit.ru" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754416Ab0ERPwr (ORCPT ); Tue, 18 May 2010 11:52:47 -0400 Sender: kvm-owner@vger.kernel.org List-ID: I just re-verified it on current stable qemu-kvm-0.12.4. The issue is still here, trivial to trigger. kvm-img create test.raw 1500G kvm ... \ -drive file=test.raw,if=virtio it fails right on the mkfs stage: mkfs.ext4 /dev/vdb Writing inode tables: end_request: I/O error, dev vdb, sector 3145727872 Buffer I/O error on device vdb, logical block 393215984 lost page write due to I/O error on vdb Buffer I/O error on device vdb, logical block 393215985 ... Buffer I/O error on device vdb, logical block 393215993 After that it continues the mkfs process, but I doubt it will produce a good filesystem. So far, only virtio has this problem. I tested with if=ide, it's slower but it went much further without any error. It's still running, but at this rate it will run for some hours more ;) At least it does not spew errors like the virtio case. Unfortunately I don't have enough free space to test. Yes the file is sparse, but it grows quite fast when mkfs is running, and I'm not sure the ~100Gb free space on the largest filesystem I have will be enough for it... but let's see. /mjt /mjt