<div dir="ltr">inline<div class="gmail_extra"><br><div class="gmail_quote">On Thu, Jan 21, 2016 at 7:54 AM, Pavel Gashev <span dir="ltr"><<a href="mailto:Pax@acronis.com" target="_blank">Pax@acronis.com</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">
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Hello,</div>
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First of all I would like to ask if anybody has an experience with using Microsoft NFS server as a storage domain.</div>
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<br></div></div></blockquote><div><br></div><div>I have used one as an ISO domain for years. It wasn't great, but it was good enough. Never a data domain though</div><div> </div><blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex"><div style="word-wrap:break-word"><div style="color:rgb(0,0,0);font-family:Calibri,sans-serif;font-size:14px">
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The main issue with MS NFS is NTFS :) NTFS doesn't support sparse files. Technically it's possible by enabling NTFS compression but it has bad performance on huge files which is our case. Also there is no option in oVirt web interface to use COW format on
NFS storage domains.</div>
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Since it looks like oVirt doesn't support MS NFS, I decided to migrate all my VMs out of MS NFS to another storage. And I hit a bug. Live storage migration
<b>silently</b> <b>corrupts</b> <b>data</b> if you migrate a disk from MS NFS storage domain. So if you shutdown just migrated VM and check filesystem you find that it has a lot of unrecoverable errors. </div>
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There are the following symptoms:</div>
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1. It corrupts data if you migrate a disk from MS NFS to Linux NFS</div>
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2. It corrupts data if you migrate a disk from MS NFS to iSCSI</div>
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3. There is no corruption if you migrate from Linux NFS to iSCSI and vice versa.</div>
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4. There is no corruption if you migrate from anywhere to MS NFS.</div>
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5. Data corruption happens after 'Auto-generated for Live Storage Migration' snapshot. So if you rollback the snapshot, you could see absolutely clean filesystem.</div>
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6. It doesn't depend on SPM. So it corrupts data if SPM is on the same host, or another.</div>
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7. There are no error messages in vdsm/qemu/system logs.</div>
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Yes, of course I could migrate from MS NFS with downtime – it's not an issue. The issue is that oVirt does silently corrupt data under some circumstances.</div>
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Could you please help me to understand the reason of data corruption?</div>
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<div><font face="Calibri,sans-serif">vdsm-4.17.13-1.el7.noarch</font></div>
<div><font face="Calibri,sans-serif">qemu-img-ev-2.3.0-31.el7_2.4.1.x86_64</font></div>
<div><font face="Calibri,sans-serif">libvirt-daemon-1.2.17-13.el7_2.2.x86_64</font></div>
<div><font face="Calibri,sans-serif">ovirt-engine-backend-3.6.1.3-1.el7.centos.noarch</font></div>
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Thank you</div>
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