From: Kern Sibbald <kern@sibbald.com>
Date: Sat, 29 Sep 2012 07:46:43 +0000 (+0200)
Subject: Add documentation on Maximum Concurrent Read Jobs
X-Git-Url: https://git.sur5r.net/?a=commitdiff_plain;h=a2597ba155ec8a82511927b8ad17ce42ac159e65;p=bacula%2Fdocs

Add documentation on Maximum Concurrent Read Jobs
---

diff --git a/docs/manuals/en/main/newbsfeatures.tex b/docs/manuals/en/main/newbsfeatures.tex
index 35fd2604..62074289 100644
--- a/docs/manuals/en/main/newbsfeatures.tex
+++ b/docs/manuals/en/main/newbsfeatures.tex
@@ -99,6 +99,25 @@ Storage {
 % to use multiple Storage Daemon, all Backup or Restore requests will be sent to
 % the specified \texttt{FDStorageAddress}.
 
+\subsection{Maximum Concurrent Read Jobs}
+This is a new directive that can be used in the {\bf bacula-dir.conf} file
+in the Storage resource.  The main purpose is to limit the number
+of concurrent Copy, Migration, and VirtualFull jobs so that
+they don't monopolize all the Storage drives causing a deadlock situation
+where all the drives are allocated for reading but none remain for
+writing.  This deadlock situation can occur when running multiple
+simultaneous Copy, Migration, and VirtualFull jobs.  
+
+\smallskip
+The default value is set to 0 (zero), which means there is no
+limit on the number of read jobs.  Note, limiting the read jobs
+does not apply to Restore jobs, which are normally started by
+hand.  A reasonable value for this directive is one half the number
+of drives that the Storage resource has rounded down.  Doing so,
+will leave the same number of drives for writing and will generally
+avoid over commiting drives and a deadlock.
+
+
 \section{Bacula Enterprise 6.0.4}
 
 \subsection{VMWare vSphere VADP Plugin}