<html><head></head><body><div style="color:#000; background-color:#fff; font-family:Helvetica Neue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif;font-size:13px"><div><span></span></div><div id="yui_3_16_0_ym19_1_1470711140752_47422" class="qtdSeparateBR"><br><br></div><div style="display: block;" id="yui_3_16_0_ym19_1_1470711140752_47426" class="yahoo_quoted"> <div id="yui_3_16_0_ym19_1_1470711140752_47425" style="font-family: Helvetica Neue-Light, Helvetica Neue Light, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 13px;"> <div id="yui_3_16_0_ym19_1_1470711140752_47424" style="font-family: HelveticaNeue, Helvetica Neue, Helvetica, Arial, Lucida Grande, Sans-Serif; font-size: 16px;"> <div id="yui_3_16_0_ym19_1_1470711140752_47423" dir="ltr"> <font face="Arial" size="2"> <hr size="1"> <b><span style="font-weight:bold;">From:</span></b> Emmanuel Florac <eflorac@intellique.com><br> <b><span style="font-weight: bold;">To:</span></b> Roger Willcocks <roger@filmlight.ltd.uk> <br><b><span style="font-weight: bold;">Cc:</span></b> Steve Brooks <sjb14@st-andrews.ac.uk>; xfs@oss.sgi.com<br> <b><span style="font-weight: bold;">Sent:</span></b> Monday, 8 August 2016, 23:44<br> <b><span style="font-weight: bold;">Subject:</span></b> Re: Advice needed with file system corruption<br> </font> </div> <div id="yui_3_16_0_ym19_1_1470711140752_47447" class="y_msg_container"><br>Le Mon, 08 Aug 2016 16:38:11 +0100<br clear="none">Roger Willcocks <<a shape="rect" ymailto="mailto:roger@filmlight.ltd.uk" href="mailto:roger@filmlight.ltd.uk">roger@filmlight.ltd.uk</a>> écrivait:<br clear="none"><br clear="none">> > <br clear="none">> > Late to the game, I just wanted to remark that I've unfortunately<br clear="none">> > verified many times that write activity during rebuilds on Adaptec<br clear="none">> > RAID controllers often creates corruption. I've reported that to<br clear="none">> > Adaptec, but they don't seem to care much...<br clear="none">> > <br clear="none">> <br clear="none"><br clear="none">> It seems like explicitly disabling individual disk drives write-back<br clear="none">> cache somewhat mitigates the effect. <br clear="none"><br clear="none"><div class="yqt7438623993" id="yqtfd82408"><div id="yui_3_16_0_ym19_1_1470711140752_47627" dir="ltr">Drives connected to RAID controllers with battery backed cache should have their caches "disabled" (they are really set to write through mode instead). By the way, I found out in lab testing that 7200 RPM SATA drives suffer a big performance loss when doing sequential writes in cache write through mode.<a id="yui_3_16_0_ym19_1_1470711140752_47582" shape="rect" href="http://oss.sgi.com/mailman/listinfo/xfs" target="_blank"></a></div></div><br><br></div> </div> </div> </div></div></body></html>