Having installed your Exalogic Virtual environment by default you
have a single template which can be used to create your vServers.
Although this template is suitable for creating simple test or
development vServers it is recommended that you look at creating
your own custom vServers that match
the environment you wish to
build and deploy. Therefore this Tea Time Snippet will take you
through
the simple process of modifying
the standard template.
Before You Start
To edit
the template you will need
the Oracle ModifyJeos Utility
which can be downloaded from
the eDelivery Site.
Once
the ModifyJeos Utility has been downloaded we can install
the rpms onto either an existing vServer or one of
the Control
vServers.
rpm -ivh ovm-modify-jeos-1.0.1-10.el5.noarch.rpm
rpm -ivh ovm-template-config-1.0.1-5.el5.noarch.rpm
Alternatively you can install
the modify jeos packages on a none
Exalogic OEL installation or a VirtualBox image. If you are doing
this, assuming OEL 5u8, you will need
the following rpms.
rpm -ivh ovm-modify-jeos-1.0.1-10.el5.noarch.rpm
rpm -ivh ovm-el5u2-xvm-jeos-1.0.1-5.el5.i386.rpm
rpm -ivh ovm-template-config-1.0.1-5.el5.noarch.rpm
Base Template
If you have installed
the modify onto a vServer running on
the
Exalogic then simply mount
the /export/common/images
from
the ZFS storage and you will be able to find
the el_x2-2_base_linux_guest_vm_template_2.0.1.1.0_64.tgz
(or similar depending which version you have) template file.
Alternatively
the latest can be downloaded from
the eDelivery Site.
Now we have
the Template tgz we will need
the extract it as
follows:
tar -zxvf el_x2-2_base_linux_guest_vm_template_2.0.1.1.0_64.tgz
This will create a directory called BASE which will contain
the
System.img (VServer image) and vm.cfg (VServer Config
information). This directory should be renamed to something more
meaning full that indicates what we have done to
the template and
then
the Simple name / name in
the vm.cfg editted for
the same
reason.
Modifying
the Template
Resizing Root File System
By default
the shipped template has a root size of 4 GB which
will leave a vServer created from it running at 90% full on
the
root disk. We can simply resize
the template by executing
the
following:
modifyjeos -f System.img -T <New Size MB>)
For example to imcrease
the default 4 GB to 40 GB we would
execute:
modifyjeos -f System.img -T 40960)
Resizing Swap
We can modify
the size of
the swap space within a template by
executing
the following:
modifyjeos -f System.img -S <New Size MB>)
For example to increase
the swap from
the default 512 MB to 4 GB
we would execute:
modifyjeos -f System.img -S 4096)
Changing RPMs
Adding RPMs
To add RPMs using modifyjeos, complete
the following steps:
Add
the names of
the new RPMs in a list file, such as
addrpms.lst. In this file, you should list each new RPM in a
separate line.
Ensure that all of
the new RPMs are in a single directory,
such as rpms.
Run
the following command to add
the new RPMs:
modifyjeos -f System.img -a <path_to_addrpms.lst> -m <path_to_rpms> -nogpg
Where <path_to_addrpms.lst> is
the path to
the location of
the addrpms.lst file, and <path_to_rpms> is
the path to
the
directory that contains
the RPMs.
The -nogpg option eliminates
signature check on
the RPMs.
Removing RPMs
To remove RPM s using modifyjeos, complete
the following steps:
Add
the names of
the RPMs (the ones you want to remove) in a
list file, such as
removerpms.lst. In this file, you should list each RPM in a
separate line.
The Oracle Exalogic Elastic Cloud Administrator's Guide provides
a list of all RPMs that must not be removed from
the vServer.
Run
the following command to remove
the RPMs:
modifyjeos -f System.img -e <path_to_removerpms.lst>
Where <path_to_removerpms.lst> is
the path to
the location
of
the
removerpms.lst file.
Mounting
the System.img
For all other modifications that are not supported by
the
modifyjeos command (adding you custom yum repositories, pre
configuring NTP, modify default NFSv4 Nobody functionality, etc)
we can mount
the System.img and access it directly. To facititate
quick and easy mounting/unmounting of
the System.img I have put
together
the simple scripts below.
MountSystemImg.sh
#!/bin/sh
#
The script assumes it's being run from
the directory containing
the System.img
# Export for later i.e. during unmount
export LOOP=`losetup -f`
export SYSTEMIMG=/mnt/elsystem
# Make Temp Mount Directory
mkdir -p $SYSTEMIMG
# Create Loop for
the System Image
losetup $LOOP System.img
kpartx -a $LOOP
mount /dev/mapper/`basename $LOOP`p2 $SYSTEMIMG
#Change Dir into mounted Image
cd $SYSTEMIMG
UnmountSystemImg.sh
#!/bin/sh
#
The script assumes it's being run from
the directory containing
the System.img
# Assume
the $LOOP & $SYSTEMIMG exist from a previous run on
the MountSystemImg.sh
umount $SYSTEMIMG
kpartx -d $LOOP
losetup -d $LOOP
Packaging
the Template
Once you have finished modifying
the template it can be simply
repackaged and then imported into EMOC as described in "Exalogic 2.0.1 Tea Break Snippets - Importing Public Server Template".
To do this we will simply cd to
the directory above that
containing
the modified files and execute
the following:
tar -zcvf <New Template Directory> <New Template Name>.tgz
The resulting.tgz file can be copied to
the images directory on
the ZFS and uploadd using
the IB network.
This entry was originally posted on
the The
Old Toxophilist Site.
