<HTML>
<HEAD>
<TITLE>Re: [Lustre-discuss] Recovery fails if clients not connected</TITLE>
</HEAD>
<BODY>
<FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'><BR>
Hrm, I think you’re right, I’m getting fuzzy on some of the details. Andreas’ posting explained it pretty clearly ... although I’ve apparently deleted somewhat foolishly. If you still have a copy of that message, would you mind forwarding it to me?<BR>
<BR>
cheers,<BR>
Klaus<BR>
<BR>
On 1/21/09 9:13 AM, "Roger Spellman" <roger@terascala.com> etched on stone tablets:<BR>
<BR>
</SPAN></FONT><BLOCKQUOTE><FONT COLOR="#000080"><FONT SIZE="4"><FONT FACE="Arial"><SPAN STYLE='font-size:13.0px'>> </SPAN></FONT></FONT></FONT><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>I believe you can connect the OSSs once the MDS has booted, and in fact, I’m pretty <BR>
> sure that the five in the ‘connected_clients: 0/5’ are in fact your OSS nodes. Each <BR>
> OST maintains a connection to the MDS while the file system is mounted, so they <BR>
> will be included in the connection count on the MDS.<BR>
<BR>
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.<BR>
</SPAN></FONT><FONT COLOR="#000080"><FONT SIZE="4"><FONT FACE="Arial"><SPAN STYLE='font-size:13.0px'> <BR>
</SPAN></FONT></FONT></FONT><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'>
</SPAN></FONT>
<P ALIGN=CENTER>
<FONT SIZE="5"><FONT FACE="Times New Roman"><SPAN STYLE='font-size:16.0px'><HR ALIGN=CENTER SIZE="2" WIDTH="100%"></SPAN></FONT></FONT>
<P>
<FONT SIZE="4"><FONT FACE="Tahoma"><SPAN STYLE='font-size:13.0px'><B>From:</B> Klaus Steden [<a href="mailto:klaus.steden@technicolor.com]">mailto:klaus.steden@technicolor.com]</a> <BR>
<B>Sent:</B> Tuesday, January 20, 2009 8:13 PM<BR>
<B>To:</B> Roger Spellman; lustre-discuss@lists.lustre.org<BR>
<B>Subject:</B> Re: [Lustre-discuss] Recovery fails if clients not connected<BR>
</SPAN></FONT></FONT><FONT SIZE="5"><FONT FACE="Times New Roman"><SPAN STYLE='font-size:16.0px'> <BR>
</SPAN></FONT></FONT><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'><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 OSS 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>
<BR>
</SPAN></FONT><FONT SIZE="5"><FONT FACE="Times New Roman"><SPAN STYLE='font-size:16.0px'> <BR>
</SPAN></FONT></FONT><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'><BR>
</SPAN></FONT></BLOCKQUOTE><FONT FACE="Verdana, Helvetica, Arial"><SPAN STYLE='font-size:12.0px'><BR>
</SPAN></FONT>
</BODY>
</HTML>