<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META http-equiv=Content-Type content="text/html; charset=iso-8859-1"> <META content="MSHTML 6.00.2900.3354" name=GENERATOR></HEAD> <BODY> <DIV><SPAN class=827301916-22072008><FONT face=Arial size=2>FWIW, I have the same issue under an HP EVA8000. I'm not really certain if directio is a solution as I have only seen the tur checker being used with an EVA.</FONT></SPAN></DIV> <DIV><SPAN class=827301916-22072008><FONT face=Arial size=2></FONT></SPAN> </DIV> <DIV><SPAN class=827301916-22072008><FONT face=Arial size=2>Daniel</FONT></SPAN></DIV> <DIV><SPAN class=827301916-22072008><FONT face=Arial size=2></FONT></SPAN> </DIV> <DIV><SPAN class=827301916-22072008><FONT face=Arial size=2></FONT></SPAN> </DIV> <DIV><SPAN class=827301916-22072008><FONT face=Arial size=2>---------------------------------------------------------------------------------------------</FONT></SPAN></DIV> <DIV><SPAN class=827301916-22072008><FONT face=Arial size=2>Date: Tue, 22 Jul 2008 16:55:27 +0200<BR>From: Hannes Reinecke <<A href="mailto:hare@suse.de">hare@suse.de</A>><BR>Subject: Re: [dm-devel] Losing paths<BR>To: device-mapper development <<A href="mailto:dm-devel@redhat.com">dm-devel@redhat.com</A>><BR>Message-ID: <<A href="mailto:4885F4DF.8010000@suse.de">4885F4DF.8010000@suse.de</A>><BR>Content-Type: text/plain; charset=ISO-8859-1; format=flowed</FONT></SPAN></DIV> <DIV> </DIV> <DIV><SPAN class=827301916-22072008><FONT face=Arial size=2>Hi John,</FONT></SPAN></DIV> <DIV> </DIV> <DIV><SPAN class=827301916-22072008><FONT face=Arial size=2>Romanowski, John (OFT) wrote:<BR>> Hi,<BR>> We had similar problem last year using sles9 and SVC 4.2.0.2, as you describe: adding/deleting a LUN causes<BR>> brief path failures for the host's remaining, unaffected LUNs.<BR>> <BR>> We were using tur checker and it turned out that while adding/deleting a LUN (and some other admin tasks)<BR>> the SVC does not respond well to test-unit-ready tur requests; but it responds perfectly well to normal read<BR>> commands. I opened IBM PMR 43118 on that if you want to ask the SVC folks about it. <BR>> <BR>> Workaround for us was to use readsector0 instead of tur as multipath path checker. <BR>> <BR>> Recent post here (see July 8, 2008) said multipath-tools is deprecating readsector0, and to use directio as<BR>> path checker, but directio was said to be much slower than tur, implying tur was better replacement than<BR>> directio for readsector0. <BR>><BR>Only for those cases where no actual read-access is necessary.<BR> <BR>> Not sure what deprecating readsector0 means for us SVC users. <BR>> <BR>It means you should be using directio there.</FONT></SPAN></DIV> <DIV> </DIV> <DIV><SPAN class=827301916-22072008><FONT face=Arial size=2>Thanks for the information, I'll see to have it included in SLES10.</FONT></SPAN></DIV> <DIV> </DIV> <DIV><SPAN class=827301916-22072008><FONT face=Arial size=2>Cheers,</FONT></SPAN></DIV> <DIV> </DIV> <DIV><SPAN class=827301916-22072008><FONT face=Arial size=2>Hannes<BR>-- <BR>Dr. Hannes Reinecke zSeries & Storage<BR><A href="mailto:hare@suse.de">hare@suse.de</A> +49 911 74053 688<BR>SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg<BR>GF: Markus Rex, HRB 16746 (AG Nürnberg)<BR></FONT></SPAN></DIV><br><br><table bgcolor=white style="color:black"><tr><td><br><br> ______________________________________________________________________<br> This email transmission and any documents, files or previous email<br> messages attached to it may contain information that is confidential or<br> legally privileged. If you are not the intended recipient or a person<br> responsible for delivering this transmission to the intended recipient,<br> you are hereby notified that you must not read this transmission and<br> that any disclosure, copying, printing, distribution or use of this<br> transmission is strictly prohibited. If you have received this transmission<br> in error, please immediately notify the sender by telephone or return email<br> and delete the original transmission and its attachments without reading<br> or saving in any manner.<br> </td></tr></table></BODY></HTML>