User guide
CMM Files Managing CMM Directory Content
page 4-8 OmniSwitch 7700/7800/8800 Switch Management Guide April 2006
Scenario 4: Rollback to Previous Version of Switch Software
Later that year, an upgraded image file for the ENI module is released from Alcatel. The network adminis-
trator loads the new file via FTP to the working directory of the switch and reboots the switch from the
working directory. Since the switch is specifically booted from the working directory, the switch is
running from the working directory.
After the reboot loads the new image file from the working directory, it is discovered that the image file
was corrupted during the FTP transfer. Rather than having a disabled switch, the network administrator
can reboot the switch from the certified directory (which has the previous, more reliable version of the
ENI image file) and wait for a new version of the ENI image. In the meantime, the administrator’s switch
is still functioning.
This is illustrated below:
Switch Rolls Back to Previous File Version
CMM Redundancy
CMM redundancy is one of the switch’s most important fail over features. For CMM redundancy, two
fully-operational CMM modules must be installed in the chassis at all times. In addition, the software on
the two CMM modules must be synchronized. (Refer to “Synchronizing the Primary and Secondary
CMMs” on page 4-21 for more information.)
When two CMMs are running in the switch, one CMM has the primary role and one CMM has the second-
ary role at any given time. The primary CMM manages the current switch operations while the secondary
CMM provides backup (also referred to as “fail over”).
RWC
RWC
RWC
RWC
1. The new
eni.img file is
installed in the
working directory.
2. The new
eni.img file is
loaded via a
reboot from the
working direc-
tory. The switch is
running from the
working directory.
3. The file is cor-
rupted and doesn’t
boot correctly.
4. Switch reboots
from certified
directory using old
eni.img file. Since
the working and
certified directo-
ries are not the
same, it will be
running from the
certified directory.