Documents installing mhVTL

doc/latex/CTA_Admin_mhVTL.tex

@@ -89,27 +89,28 @@ Slot 8:
 
 \subsection{\texttt{udev} rules}
 
-Create \texttt{/etc/udev/rules.d/00-castor-tape.rules} and add a rule to create the SCSI media changer device:
+Create \texttt{/etc/udev/rules.d/00-cta.rules}. Add rules to create symbolic links to the first tape drive and the SCSI
+media changer device (IBM tape library specific):
 \begin{lstlisting}
-KERNEL=="sg*", BUS=="scsi", SYSFS{type}=="8", SYMLINK:="smc"
-KERNEL=="sg*", MODE:="0666", GROUP:="disk"
+# Create symlink /dev/tape pointing to the (first) tape drive
+SUBSYSTEM=="scsi_tape", KERNEL=="nst0", SYMLINK:="tape"
+
+# Create symlink /dev/smc pointing to the SCSI media changer
+SUBSYSTEM=="scsi_generic", KERNEL=="sg*", ATTRS{type}=="8", SYMLINK:="smc"
 \end{lstlisting}
-Also create \texttt{/etc/udev/rules.d/99-tape.rules} to set the permissions for the \texttt{st} group. This group is
-created automatically by the castor RPMs:
+Also add rules for permissions for the SCSI devices. This example sets global read/write permissions to all devices;
+in production, you should configure more nuanced rules based on the \texttt{st} group. This group is created
+automatically by the castor RPMs:
 \begin{lstlisting}
-# Udev rules setting the permissions on the tape device files for 
-# CASTOR's tapeserverd operations.
-
-KERNEL=="nst*", GROUP="st"
+# Set the permissions and group of the tape devices
+KERNEL=="nst*", MODE:="0666"
+KERNEL=="st*",  MODE:="0666"
+KERNEL=="sg*",  MODE:="0666"
 \end{lstlisting}
-
-\begin{alertbox}
-When I tried this in Docker, it didn't work. I didn't spend any time figuring out why, instead I just created the
-symbolic link manually:
+To apply the rules without rebooting:
 \begin{lstlisting}
-# ln -s /dev/sg3 /dev/smc
+# sudo udevadm trigger
 \end{lstlisting}
-\end{alertbox}
 
 \section{Start mhVTL}
 
@@ -121,7 +122,7 @@ The service requires the mhVTL kernel module \texttt{mhvtl.ko}, which should be
 
 After starting the mhVTL daemon, the files for the virtual tapes will be created automatically:
 \begin{lstlisting}
-# /bin/ls -lRF /opt/mhvtl/
+# ls -lRF /opt/mhvtl/
 /opt/mhvtl/:
 total 0
 drwxrwx---. 7 vtl vtl 86 May 15 09:58 10/
@@ -189,54 +190,28 @@ Check the status of the drive:
 Rewind the tape:
 \begin{lstlisting}
 # mt -f /dev/nst0 rewind
-# mt -f /dev/nst0 status
-\end{lstlisting}
-Read VOL1 label (80 byte block):
-\begin{lstlisting}
-# dd if=/dev/nst0 bs=262144 count=1
-\end{lstlisting}
-Read HDR1 label (80 byte block):
-\begin{lstlisting}
-# dd if=/dev/nst0 bs=262144 count=1
-\end{lstlisting}
-Read HDR2 label (80 byte block):
-\begin{lstlisting}
-# dd if=/dev/nst0 bs=262144 count=1
-\end{lstlisting}
-Read UHL1 label (80 byte block):
-\begin{lstlisting}
-# dd if=/dev/nst0 bs=262144 count=1
-\end{lstlisting}
-Read end of tape file (0 records out):
-\begin{lstlisting}
-# dd if=/dev/nst0 bs=262144 count=1
-\end{lstlisting}
-Read first block of user's file (256KiB):
-\begin{lstlisting}
-# dd if=/dev/nst0 bs=262144 count=1
-\end{lstlisting}
-Read the rest of the user's file if there is more.
-
-Read end of tape file (0 records out):
-\begin{lstlisting}
-# dd if=/dev/nst0 bs=262144 count=1
-\end{lstlisting}
-Read EOF1 label (80 byte block):
-\begin{lstlisting}
-# dd if=/dev/nst0 bs=262144 count=1
-\end{lstlisting}
-Read EOF2 label (80 byte block):
-\begin{lstlisting}
-# dd if=/dev/nst0 bs=262144 count=1
-\end{lstlisting}
-Read UTL1 label (80 byte block):
-\begin{lstlisting}
-# dd if=/dev/nst0 bs=262144 count=1
 \end{lstlisting}
-Read end of tape file (0 records out):
+Read the first block from the tape:
 \begin{lstlisting}
 # dd if=/dev/nst0 bs=262144 count=1
 \end{lstlisting}
+Successively repeating the above command will read out subsequent blocks from the tape in the following format:
+\begin{itemize}
+\item VOL1 label (80 byte block)
+\item HDR1 label (80 byte block)
+\item HDR2 label (80 byte block)
+\item UHL1 label (80 byte block)
+\item End of tape file (0 records out)
+\item First block of user's file (256 KiB)
+\item Second block of user's file (256 KiB)
+\item \ldots
+\item Last block of user's file ($\leq$ 256 KiB)
+\item End of tape file (0 records out)
+\item EOF1 label (80 byte block)
+\item EOF2 label (80 byte block)
+\item UTL1 label (80 byte block)
+\item End of tape file (0 records out)
+\end{itemize}
 Rewind the tape:
 \begin{lstlisting}
 # mt -f /dev/nst0 rewind