189 lines
3.3 KiB
HTML
189 lines
3.3 KiB
HTML
<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN">
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<HTML
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>DFSA ? MFS ? </TITLE
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NAME="GENERATOR"
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TITLE="Common Problems"
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TITLE="I often get errors: No such process"
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><TR
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><TH
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>The openMosix HOWTO: </TH
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>Chapter 12. Common Problems</TD
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NAME="AEN1285"
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>12.5. DFSA ? MFS ?</H1
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><P
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>People often get confused about what exactly MFS and DFSA
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are.
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As discussed before in the howto MFS is the feature of openMosix
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that enables you access to remote filesystems as if those
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filesystems were locally mounted. They are mostly mounted on
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/mfs . A common misunderstanding is that you need MFS in order
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to have openMosix working, this is not true, however it can make
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things easier.
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</P
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><P
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>With DFSA enabled, system calls will be executed on the remote
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node withouth migrating the process back to it's home node. This
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behaviour (direct filesystem access) causes processes migratiing
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to the data and not the other way around (which is common). If
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DFSA is not enabled MfS is "just" a non-caching
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network-filesystem.</P
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><P
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>
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Very generally speaking, if you don't have DFSA turned on, each and
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every I/O will go to the home node for execution. With DFSA turned on,
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if the file happens to be residing on the node where the process finds
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itself then the I/O will happen locally. </P
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><P
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> A very common error is that people mix kernels with DFSA enabled
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and disabled. So one has to have a way to find out wether DFSA
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is actually enabled. This information can be obtained by typing
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<TABLE
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BORDER="0"
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BGCOLOR="#E0E0E0"
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WIDTH="100%"
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><TR
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><TD
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><FONT
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COLOR="#000000"
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><PRE
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CLASS="PROGRAMLISTING"
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>cat /proc/hpc/admin/version</PRE
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></FONT
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></TD
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></TR
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></TABLE
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> </P
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>Prev</A
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>I often get errors: No such process</TD
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>Python Troubles</TD
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> |