251
edits
Changes
m
Text replacement - "<htmlet>xen<htmlet>" to "<htmlet>xen</htmlet>"
<table border="0" cellspacing="0" width="100%">
<tr>
<td width="20%">[[Adding Disk, CDROM and DVD Devices to a Running Xen domainU Guest System|Previous]]<td align="center">[[Xen Virtualization Essentials|Table of Contents]]<td width="20%" align="right">[[Migrating Xen domainU Guests Between Host Systems|Next]]</td>
<tr>
<td width="20%">Adding Disk, CDROM and DVD Devices to a Running Xen domainU Guest System<td align="center"><td width="20%" align="right">Migrating Xen domainU Guests Between Host Systems</td>
</table>
<hr>
<htmlet>xen</htmlet>
So far in this book we have focused primarily on the creation of Xen guest domains (domainU). By this stage it is safe to assume that you now have one or more domainU systems up and running on your server or desktop. Given this assumption, this chapter of [[Xen Virtualization Essentials]] will be dedicated to providing an overview of the tools and techniques that may be employed to monitor a Xen based environment.
== Monitoring Xen Performance with XenMon ==
The ''XenMon'' tool is useful for monitoring the performance Xen domains, particularly when identifying with which domains are responsible for the highest I/O or processing loads on a system.
XenMon is started from the command-line using the ''xenmon.py'' command. The following figure shows a typical XenMon session:
</pre>
XenMon accepts a range of command-line options which control various aspects of the monitoring. For a breakdown of these options simply pass the ''--help'' argument through through to ''xenmon.py'':
<pre>
== Monitoring Performance with XenTop ==
Anyone who has been using UNIX or Linux for any length of time (particularly since the days before GUI desktop environments) is probably familiar with the ''top'' command. This long standing tool is used to display information, such as CPU and memory usage, about processes running on a particular system. One of the best features of ''top'' is that is puts the process making the heaviest use of a particular resource at the top of the list. When a system is exhibiting performance degradation the ''top'' command is often the first port of call for the experienced system administrator.
''XenTop'' is essentially a Xen version of the original ''top'' utility and is used to show information about all the domains running on a particular system.
The ''XenTop'' tool is launched by typing ''xentop'' as root at the command-line. Whilst xentop can be launched without any command-line options, it is worth knowing that a range of options are available and can be listed using the --help flag:
<pre>
xentop --help
Usage: xentop [OPTION]
Displays ongoing information about xen vm resources
-h, --help display this help and exit
-V, --version output version information and exit
-d, --delay=SECONDS seconds between updates (default 3)
-n, --networks output vif network data
-x, --vbds output vbd block device data
-r, --repeat-header repeat table header before each domain
-v, --vcpus output vcpu data
-b, --batch output in batch mode, no user input accepted
-i, --iterations number of iterations before exiting
Report bugs to <[email protected]>.
</pre>
The following figure shows sample output from a XenTop session:
[[Image:XenTop_display.jpg|Monitoring Xen Domains with XenTop]]
<htmlet>xen</htmlet>
<hr>
<table border="0" cellspacing="0" width="100%">
<tr>
<td width="20%">[[Adding Disk, CDROM and DVD Devices to a Running Xen domainU Guest System|Previous]]<td align="center">[[Xen Virtualization Essentials|Table of Contents]]<td width="20%" align="right">[[Migrating Xen domainU Guests Between Host Systems|Next]]</td>
<tr>
<td width="20%">Adding Disk, CDROM and DVD Devices to a Running Xen domainU Guest System<td align="center"><td width="20%" align="right">Migrating Xen domainU Guests Between Host Systems</td>
