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| Newer page: | version 16 | Last edited on Thursday, August 7, 2008 8:54:07 pm | by GreigMcGill | Revert |
| Older page: | version 13 | Last edited on Monday, May 21, 2007 12:33:15 pm | by CraigBox | Revert |
@@ -1,49 +1,52 @@
!!!ntpdate(1) has no effect
Xen by default just uses the dom0's clock, which isn't updated within the domU's. Either set <tt>/proc/xen/independent_wallclock</tt> to 1 (so that this domU has an indepedent clock from the host dom0, or set the clock in the dom0.
!!!Making a tape drive available to a guest via iSCSI
-__This is specifically for ~XenSource's range of products
, although the principles will of course work in other Xen implementations__
+__This is specifically for Citrix
~XenServer
, although the principles will of course work in other Xen implementations__
I recently had a scenario where I was replacing two Windows servers with ~XenServer guests. This was fine, but we needed a way to backup to the existing SCSI DDS4 DAT drive. After failing to make PCI passthrough work, I settled on the much nicer method of providing the tape drive via an iSCSI target on the ~XenServer Host (Dom0). Here is how I achieved this.
-Note 1: This is totally unsupported by ~XenSource
+Note 1: This is totally unsupported by Citrix
-Note 2: I've used the ~XenSource
terminology "host" instead of Dom0, as this applies to the ~XenSource
commercial implementation of Xen. It will probably work fine on OSS Xen, but you can just install the normal kernel dev packages and ignore the DDK stuff.
+Note 2: I've used the ~XenServer
terminology "host" instead of Dom0, as this applies to the Citrix
commercial implementation of Xen. It will probably work fine on OSS Xen, but you can just install the normal kernel dev packages and ignore the DDK stuff.
-* Download the [
Xen DDK|http://tx.downloads.xensource
.com/products/ddk/index.php]
+Note 3: This is for ~XenServer 4.1., but the principles are the same for previous versions. Just ensure you understand each step rather than following blindly.
+
+
+
* Download the Xen 4.1
DDK from citrix
.com
* The DDK is an ISO containing a VM with a development environment. Import it to your Xen host, and start it.
-* Download [
iscsitarget .4.14|
http://optusnet.dl.sourceforge.net/sourceforge/iscsitarget/iscsitarget-.4.14.tar.gz] (you MUST use this version, as the patch for rawio support will not cleanly apply to .4.15)
into your DDK VM.
-* Download the patch for [
rawio support|
http://sourceforge.net/mailarchive/attachment.php?list_name=iscsitarget-devel&message_id=1170171101.2822.23.camel@localhost.localdomain&counter=1]
into your DDK VM (assuming you're saving it in /tmp)
+* Download iscsitarget .4.14 (you MUST use this version, as the patch for rawio support will not cleanly apply to .4.15) from
http://optusnet.dl.sourceforge.net/sourceforge/iscsitarget/iscsitarget-.4.14.tar.gz into your DDK VM.
+* Download the patch for rawio support from
http://sourceforge.net/mailarchive/attachment.php?list_name=iscsitarget-devel&message_id=1170171101.2822.23.camel@localhost.localdomain&counter=1 into your DDK VM (assuming you're saving it in /tmp)
* Now do the following:
<pre>
yum install kernel-devel bison flex
tar -zxvf iscsitarget-0.4.14.tar.gz
cd iscsitarget-0.4.14
patch -p0 < /tmp/raw.p
make
</pre>
-* scp the entire iscsitarget-.4.14 directory to your destination Xen host, and on that host do:
+* scp the entire iscsitarget-.4.14 directory to your destination Xen host, and on that host (after enabling the base repo in /etc/yum.repos.d/CentOS-Base.repo)
do:
<pre>
yum install make gcc
cd iscsitarget-0.4.14
make install
-mkdir /lib/modules/2.6.16.38
-xs3.2..531.3960xen
/kernel/iscsi
-cp kernel/iscsi_trgt.ko /lib/modules/2.6.16.38
-xs3.2..531.3960xen
/kernel/iscsi
+mkdir /lib/modules/`uname
-r`
/kernel/iscsi
+cp kernel/iscsi_trgt.ko /lib/modules/`uname
-r`
/kernel/iscsi
depmod -aq
</pre>
The last three steps are required because <tt>make install</tt> will not copy the kernel module correctly outside the target environment.
-* Now edit your <tt>/etc/ietd.conf</tt> and configure the tape as per the following example snippet:
+* Now edit your <tt>/etc/ietd.conf</tt> and configure the tape as per the following example snippet (cat /proc/scsi/scsi for the correct [HCIL] values for your SCSI tape drive, this is an example only)
:
<pre>
Target iqn.2007-04.com.example:tape0
Lun 0 H=1,C=0,I=6,L=0,Type=rawio
Type 1
</pre>
* Save and do <tt>/etc/init.d/iscsi-target start</tt>
-* Modify <tt>/etc/sysconfig/iptables</tt> to allow port 3060
tcp from the IP addresses running the initiator.
+* Modify <tt>/etc/sysconfig/iptables</tt> to allow port 3260
tcp from the IP addresses running the initiator.
* Attach to the target using the initiator of your choice.
-----
CategoryXen
