Update autochanger chapter

diff --git a/docs/manual/autochangers.tex b/docs/manual/autochangers.tex
index f2dcb2c5d359c685eb3a2ef20f475dfbe907fa37..c5a350db95f29e8e2a21b1926f4f7a601fd8c363 100644 (file)
--- a/docs/manual/autochangers.tex
+++ b/docs/manual/autochangers.tex
@@ -40,7 +40,7 @@ which is explained in more detail after this list:
 In version 1.37 and later, there is a new \ilink{Autochanger
 resource}{AutochangerRes} that permits you to group Device resources thus
 creating a multi-drive autochanger. If you have an autochanger,
-you must use this new resource. 
+you {\bf must} use this new resource. 
 
 Bacula uses its own {\bf mtx-changer} script to interface with a program
 that actually does the tape changing.  Thus in principle, {\bf mtx-changer}
@@ -71,6 +71,15 @@ supported by {\bf mtx} at the following link:
 The home page for the {\bf mtx} project can be found at: 
 \elink{http://mtx.opensource-sw.net/}{http://mtx.opensource-sw.net/}. 
 
+Note, we have feedback from some users that there are certain
+incompatibilities between the Linux kernel and mtx.  For example between
+kernel 2.6.18-8.1.8.el5 of CentOS and RedHat and version 1.3.10 and 1.3.11
+of mtx.  This was fixed by upgrading to a version 2.6.22 kernel.
+
+In addition, apparently certain versions of mtx, for example, version
+1.3.11 limit the number of slots to a maximum of 64. The solution was to
+use version 1.3.10.
+
 If you are having troubles, please use the {\bf auto} command in the {\bf
 btape} program to test the functioning of your autochanger with Bacula. When
 Bacula is running, please remember that for many distributions (e.g. FreeBSD,
@@ -78,6 +87,14 @@ Debian, ...) the Storage daemon runs as {\bf bacula.tape} rather than {\bf
 root.root}, so you will need to ensure that the Storage daemon has sufficient
 permissions to access the autochanger. 
 
+Some users have reported that the the Storage daemon blocks under certain
+circumstances in trying to mount a volume on a drive that has a different
+volume loaded.  As best we can determine, this is simply a matter of
+waiting a bit.  The drive was previously in use writing a Volume, and
+sometimes the drive will remain BLOCKED for a good deal of time (up to 7
+minutes on a slow drive) waiting for the cassette to rewind and to unload
+before the drive can be used with a different Volume.
+
 \label{SCSI devices}
 \section{Knowing What SCSI Devices You Have}
 \index[general]{Have!Knowing What SCSI Devices You }