Coda File System

Re: What happens if the SCM dies?

From: David J. M. Karlsen <>
Date: Thu, 13 Dec 2001 14:38:38 -0800
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Jan Harkes wrote:<br>
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  <pre wrap="">On Thu, Dec 13, 2001 at 10:23:40AM -0800, David J. M. Karlsen wrote:<br></pre>
  <blockquote type="cite">
    <pre wrap="">I'm looking into coda to use it for a cluster of minimum two machines. <br>The replication seems to be fine - so I shouldn't loose any data. But as <br>it's only possible to have one SCM - I wonder what happens if the SCM <br>dies (for good that is - let's say the drives fails due to HW trouble) - <br>will the other non-SCM server with the replica still feed all clients - <br>and all activity goes ahead undisturbed?<br></pre>
    <pre wrap=""><!----><br>If the SCM dies the only thing that is hindered is adding new<br>users/changing passwords and the creation of new volumes.</pre>
they can still authenticate as well? (eg. use clog?)
    <blockquote type="cite" cite="">
      <pre wrap="">It is trivially to select one of the other server as the new SCM. All<br>required data is already replicated, you just need to tell every server<br>who the new SCM is<br>    ( echo 'newscmhostname' &gt; /vice/db/scm ;<br>      /etc/rc.d/init.d/update.init restart )</pre>
      <blockquote type="cite" cite="">
        <pre wrap="">Regular Coda clients accessing the system are not disturbed at all.<br></pre>
nice! I'm really hungy for this scheme now :)<br>
Some things abount the README at the ftp site:<br>
first: it's for version 4.6.1 - should't it just be removed?<br>
it referres to a venus-setup script that does not exist.<br>
it tells me to run createvol_rep after running vice-setup.<br>
Is this wrong? Beacuse when I first went into /coda/&lt;myvol&gt; the &lt;myvol&gt;
existed. I ran createvol_rep - and now it's not there anymore... Doesn't
the vice-setup do the createvol_rep as well?<br>
second: the README says that the LOG has to be large - isn't this wrong?
The RVM needs to be large - the LOG doesn't?<br>
codasrv uses and awfaul amount of mem - (eg. equal to the size of RVM).<br>
I thougth it just did this when using files for LOG/RVM (beacuse they are
mmap'ed) - but when I switched over to using partitions - it uses the same
amount anway - is there a way to awoid this - the testmachine has only got
64 megs.<br>
(Does this have anyting to do with the privatemap=0/1 in the /etc/coda/server.conf?)<br>
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          <pre class="moz-signature" cols="$mailwrapcol">-- <br>David J. M. Karlsen<br><br>+47 90 68 22 43</pre>
Received on 2001-12-13 17:43:27