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<title>Re: [Lustre-discuss] Recovery fails if clients not connected</title>
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<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'>> </span></font><font size=1
face=Verdana><span style='font-size:9.0pt;font-family:Verdana'>I believe you
can connect the OSSs once the MDS has booted, and in fact, I’m pretty <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Verdana><span style='font-size:9.0pt;
font-family:Verdana'>> sure that the five in the ‘connected_clients:
0/5’ are in fact your <st1:City w:st="on"><st1:place w:st="on">OSS</st1:place></st1:City>
nodes. Each <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Verdana><span style='font-size:9.0pt;
font-family:Verdana'>> OST maintains a connection to the MDS while the file
system is mounted, so they <o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Verdana><span style='font-size:9.0pt;
font-family:Verdana'>> will be included in the connection count on the MDS.<o:p></o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Verdana><span style='font-size:9.0pt;
font-family:Verdana'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Verdana><span style='font-size:9.0pt;
font-family:Verdana'>Klaus, thanks for this information. But, the 0/5 is the
number of clients. An MDT is a client of an OST, not the other way around.</span></font><font
size=2 color=navy face=Arial><span style='font-size:10.0pt;font-family:Arial;
color:navy'><o:p></o:p></span></font></p>
<p class=MsoNormal><font size=2 color=navy face=Arial><span style='font-size:
10.0pt;font-family:Arial;color:navy'><o:p> </o:p></span></font></p>
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<p class=MsoNormal><b><font size=2 face=Tahoma><span style='font-size:10.0pt;
font-family:Tahoma;font-weight:bold'>From:</span></font></b><font size=2
face=Tahoma><span style='font-size:10.0pt;font-family:Tahoma'> Klaus Steden
[mailto:klaus.steden@technicolor.com] <br>
<b><span style='font-weight:bold'>Sent:</span></b> Tuesday, January 20, 2009
8:13 PM<br>
<b><span style='font-weight:bold'>To:</span></b> Roger Spellman;
lustre-discuss@lists.lustre.org<br>
<b><span style='font-weight:bold'>Subject:</span></b> Re: [Lustre-discuss] Recovery
fails if clients not connected</span></font><o:p></o:p></p>
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<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
<p class=MsoNormal><font size=1 face=Verdana><span style='font-size:9.0pt;
font-family:Verdana'><br>
Hi Roger,<br>
<br>
I believe you can connect the OSSs once the MDS has booted, and in fact,
I’m pretty sure that the five in the ‘connected_clients: 0/5’
are in fact your <st1:City w:st="on"><st1:place w:st="on">OSS</st1:place></st1:City>
nodes. Each OST maintains a connection to the MDS while the file system is
mounted, so they will be included in the connection count on the MDS.<br>
<br>
However, regardless of the state — if your MDS is online and the MDT is
mounted, you can start up the OSS nodes and corresponding OSTs at any time;
clients attempting to make transactions will have their I/O operations block
(or fail, depending on the MDS config) until the missing nodes come back
online.<br>
<br>
hth,<br>
Klaus<br>
<br>
<br>
<br>
</span></font><o:p></o:p></p>
<p class=MsoNormal><font size=3 face="Times New Roman"><span style='font-size:
12.0pt'><o:p> </o:p></span></font></p>
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