On Wednesday, July 02, 2014 1:06 PM, Pete Zaitcev <zait...@redhat.com> wrote:
Thanks for the detailed explanation. Let me clarify the behavior of swift. (1) Use ext4 on devices. (2) Corrupt the data on (1)'s filesystem (3) Move corrupt files to lost+found without a trace by ext4's fsck (4) Cannot recognize (3) by Swift's auditors so hashes.pkl is not updated. Is above sequence correct? If it's correct, I understand we better to use xfs. Thanks in advance, Hisashi Osanai > -----Original Message----- > From: Pete Zaitcev [mailto:zait...@redhat.com] > Sent: Wednesday, July 02, 2014 1:06 PM > To: Osanai, Hisashi/小山内 尚 > Cc: OpenStack Development Mailing List (not for usage questions) > Subject: Re: [openstack-dev] Swift: reason for using xfs on devices > > On Wed, 2 Jul 2014 00:16:42 +0000 > "Osanai, Hisashi" <osanai.hisa...@jp.fujitsu.com> wrote: > > > So I think if performance of swift is more important rather than > scalability of it, it is a > > good idea to use ext4. > > The real problem is what happens when your drives corrupt the data. > Both ext4 and XFS demonstrated good resilience, but XFS leaves empty > files in directories where corrupt files were, while ext4's fsck moves > them to lost+found without a trace. When that happens, Swift's auditors > cannot know that something was amiss and the replication is not > triggered (because hash lists are only updated by auditors). > > Mr. You Yamagata worked on a patch to address this problem, but did > not complete it. See here: > https://review.openstack.org/11452 > > -- Pete _______________________________________________ OpenStack-dev mailing list OpenStack-dev@lists.openstack.org http://lists.openstack.org/cgi-bin/mailman/listinfo/openstack-dev