<html><head><meta http-equiv="Content-Type" content="text/html charset=utf-8"></head><body style="word-wrap: break-word; -webkit-nbsp-mode: space; -webkit-line-break: after-white-space;" class="">I just got bitten by this particular problem, on a heavily used disk image. I'm trying to defragment the disk images. Hop this will help.<div class=""><br class=""></div><div class=""><br class=""><div><blockquote type="cite" class=""><div class="">Le 8 juin 2017 à 07:19, Markus Stockhausen <<a href="mailto:stockhausen@collogia.de" class="">stockhausen@collogia.de</a>> a écrit :</div><br class="Apple-interchange-newline"><div class=""><div style="font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); direction: ltr; font-family: Arial; font-size: 10pt;" class=""><div class=""><div class=""><div class=""><div class=""><div class=""><div class=""><div class=""><div style="font-family: Tahoma; font-size: 13px;" class="">Hi Fernando,<span class="Apple-converted-space"> </span></div><div style="font-family: Tahoma; font-size: 13px;" class=""><br class=""></div><div style="font-family: Tahoma; font-size: 13px;" class="">we personally like XFS very much. But XFS + qcow2 (even for snapshots in OVirt)</div><div style="font-family: Tahoma; font-size: 13px;" class="">comes close to a no-go these days. We are experience excessive fragmentation.</div><div style="font-family: Tahoma; font-size: 13px;" class="">For more info see unresolved Redhat Info:</div><div class=""><font face="Tahoma" class=""><span style="font-size: 13px;" class=""><br class=""></span></font></div><div class=""><font face="Tahoma" class=""><span style="font-size: 13px;" class=""><a href="https://access.redhat.com/solutions/532663" class="">https://access.redhat.com/solutions/532663</a></span></font></div><div style="font-family: Tahoma; font-size: 13px;" class=""><br class=""></div><div style="font-family: Tahoma; font-size: 13px;" class="">Even with tuning the XFS allocation policy on the qcow2 directory with </div><div style="font-family: Tahoma; font-size: 13px;" class=""><br class=""></div><div class=""><font face="Tahoma" class=""><span style="font-size: 13px;" class="">xfs_io -c 'extsize -R 2M' <qcow2-dir></span></font></div><div style="font-family: Tahoma; font-size: 13px;" class=""><br class=""></div><div style="font-family: Tahoma; font-size: 13px;" class="">A nice 3rd party explanation can be found here:</div><div style="font-family: Tahoma; font-size: 13px;" class=""><br class=""></div><div class=""><font face="Tahoma" class=""><span style="font-size: 13px;" class=""><a href="https://blog.codecentric.de/en/2017/04/xfs-possible-memory-allocation-deadlock-kmem_alloc/" class="">https://blog.codecentric.de/en/2017/04/xfs-possible-memory-allocation-deadlock-kmem_alloc/</a></span></font></div><div style="font-family: Tahoma; font-size: 13px;" class=""><br class=""></div><div style="font-family: Tahoma; font-size: 13px;" class="">Markus</div><div style="font-family: Tahoma; font-size: 13px;" class=""><br class=""></div></div></div></div></div></div></div></div><div style="font-family: 'Times New Roman'; font-size: 16px;" class=""><hr tabindex="-1" class=""><div id="divRpF447039" style="direction: ltr;" class=""><font face="Tahoma" size="2" class=""><b class="">Von:</b><span class="Apple-converted-space"> </span><a href="mailto:users-bounces@ovirt.org" class="">users-bounces@ovirt.org</a><span class="Apple-converted-space"> </span>[<a href="mailto:users-bounces@ovirt.org" class="">users-bounces@ovirt.org</a>]" im Auftrag von "FERNANDO FREDIANI [<a href="mailto:fernando.frediani@upx.com" class="">fernando.frediani@upx.com</a>]<br class=""><b class="">Gesendet:</b><span class="Apple-converted-space"> </span>Mittwoch, 7. Juni 2017 23:35<br class=""><b class="">An:</b><span class="Apple-converted-space"> </span><a href="mailto:users@ovirt.org" class="">users@ovirt.org</a><br class=""><b class="">Betreff:</b><span class="Apple-converted-space"> </span>[ovirt-users] Performance differences between ext4 and XFS<br class=""></font><br class=""></div><div class=""></div><div class=""><font face="arial, helvetica, sans-serif" class="">Just wanted to find out what filesystem people are using to host<span class="Apple-converted-space"> </span></font>Virtual Machines in qcow2 files in a filesystem in Localstorage, ext4 or XFS ?<br class=""><br class="">I normally like XFS for big files which is the case fo VMs, but wondered if anyone could see any performance advantage when compared with ext4.<br class=""><br class="">Fernando<br class=""></div></div></div><span id="cid:0583B5F5-532F-462E-A18F-E203C8395CED@dsone.3ds.com"><InterScan_Disclaimer.txt></span><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); float: none; display: inline !important;" class="">_______________________________________________</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""><span style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255); float: none; display: inline !important;" class="">Users mailing list</span><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""><a href="mailto:Users@ovirt.org" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class="">Users@ovirt.org</a><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""><a href="http://lists.ovirt.org/mailman/listinfo/users" style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class="">http://lists.ovirt.org/mailman/listinfo/users</a><br style="font-family: Helvetica; font-size: 12px; font-style: normal; font-variant-caps: normal; font-weight: normal; letter-spacing: normal; orphans: auto; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; widows: auto; word-spacing: 0px; -webkit-text-stroke-width: 0px; background-color: rgb(255, 255, 255);" class=""></div></blockquote></div><br class=""></div></body></html>