Original Publication Date: 03/04/2013
Updated Date: 10/13/2016
This article applies to BIG-IP 11.x through 12.x. For information about other versions, refer to the following article:
The Maintenance Operating System (MOS) is an additional boot location that is automatically created when the BIG-IP system is installed.
The BIG-IP system uses MOS for maintenance purposes. For example, the BIG-IP system automatically reboots into MOS to perform installations that require reformatting the drives. However, you can also manually boot the BIG-IP system into MOS at any time to perform certain recovery tasks. For example, if the BIG-IP system no longer boots from any of the normal boot locations, you can use MOS to retrieve important files before proceeding to reimage the system. For information, refer to the following procedures:
Booting the BIG-IP system into MOS
Using MOS to mount a volume and retrieve files
Configuring MOS for network access
Transferring files to/from the BIG-IP system while running MOS
Using MOS to perform an installation
The command output appears similar to the following example:
ACTIVE '/dev/vg-db-sda/dat.share.1' [30.00 GB] normal
ACTIVE '/dev/vg-db-sda/dat.log.1' [7.00 GB] normal
ACTIVE '/dev/vg-db-sda/set.1.root' [256.00 MB] normal
ACTIVE '/dev/vg-db-sda/set.1._usr' [1.34 GB] normal
ACTIVE '/dev/vg-db-sda/set.1._config' [512.00 MB] normal
ACTIVE '/dev/vg-db-sda/set.1._var' [3.00 GB] normal
ACTIVE '/dev/vg-db-sda/set.2.root' [256.00 MB] normal
ACTIVE '/dev/vg-db-sda/set.2._usr' [1.34 GB] normal
ACTIVE '/dev/vg-db-sda/set.2._config' [512.00 MB] normal
ACTIVE '/dev/vg-db-sda/set.2._var' [3.00 GB] normal
ACTIVE '/dev/vg-db-sda/set.3.root' [256.00 MB] normal
ACTIVE '/dev/vg-db-sda/set.3._usr' [1.25 GB] normal
ACTIVE '/dev/vg-db-sda/set.3._config' [512.00 MB] normal
ACTIVE '/dev/vg-db-sda/set.3._var' [3.00 GB] normal
ACTIVE '/dev/vg-db-hda/dat.maint.1' [200.00 MB] normal
Note: Some directories on the BIG-IP system are links to other directories. For example, the /var/tmp directory is a link to the /shared/tmp directory. Therefore, if you want to retrieve a file from the /var/tmp directory, you must mount the logical volume for the /shared directory.
mount <logical volume> /mnt/temp
mount /dev/vg-db-sda/set.2._config /mnt/temp
cp /mnt/temp/bigip.conf /
cp /mnt/temp/bigip_base.conf /
When the BIG-IP system is running MOS, the only configurable network interface is the management interface. Perform the following procedure to configure MOS for network access.
ifconfig eth0 <ip> netmask <mask> broadcast <broadcast> up
ifconfig eth0 172.29.21.90 netmask 255.255.255.0 broadcast 172.29.21.255 up
route add default gw <ip>
route add default gw 172.29.21.1
echo 'nameserver <ip>' > /etc/resolv.conf
echo 'nameserver 172.29.28.3' > /etc/resolv.conf
After you have configured MOS for network access, you can transfer files to and from the BIG-IP system using the scp utility.
scp firstname.lastname@example.org:/root/BIGIP-188.8.131.52.0.606.iso /
scp /bigip.conf email@example.com:/root/
Note: MOS uses a temporary memory file system as its root file system; therefore, the available free space is approximately the same as the physical memory installed in the system. Therefore, on older platforms, you may not have enough free space to copy large files to the MOS environment. However, you do not need to copy an ISO image to the MOS environment to perform an installation. This process is covered in the next section.
You can use the image2disk utility to perform an installation while booted into MOS. For information about how to use the image2disk utility, type the image2disk --help command.
The image2disk utility accepts product repositories other than a local ISO image file. For example, it is possible to install the BIG-IP system using a remote HTTP server as the product repository. To do so, type a command similar to the following example:
image2disk --format=volumes --nosaveconfig http://10.0.0.10/12_0_0
Note: When the product repository is an HTTP URL, this must correspond to the root directory of a mounted CD/DVD or loopback-mounted ISO image file.
For information about using the image2disk utility with a local ISO image file, refer to SOL14558: Using the MOS to perform a local installation.