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Cisco MGX 8850 Routing Switch Command Reference
Release 2.0, Part Number 78-10467-04 Rev C0, October 2001
Chapter2 Shelf Management Commands loadrev
loadrev
Load Revision
Downloads a firmware image from th e F W directory on the disk to flash me mo r y on t he ta rge ted c ar d.
Executing is the first step in perform in g a g r ace ful firmware upgrade. A graceful revision ch an ge
preserves the configuration of the car d an d m inim izes any data loss that could re sul t fr om the brief
disruption in servic e.
Although loadrev runs on a PXM45, the target can be either a se rvice or the PXM45 itself. The system
automatically determines which card in a redundant setup is active and which is standby. Specifying the
active card slot is sufficient. For example, if a PXM45 is th e ta rget , you can s pe cif y eit her s lo t 7 or s lot
8 regardless of the active slot number.
The sequence of commands for a grac eful revision change appear in the fo ll owing li s t. See Table 2 -10
and Table 2 -11 for a c lari fication of the various states within t hi s s eq u en ce.
1. loadrev loads a firmware version f rom t he h ar d di sk to a card’s memory. In a non-re du ndant card
setup, loadrev does not cause the system to reset the car d .
2. runrev causes the primary card to start running the new version. For a redundant pair of cards, the
standby becomes the active card then starts running the new version.
3. If an unacceptable problem occur s , the opt iona l abortrev command restores the previous vers ion of
firmware as well as the previous dat ab ase contents.
4. commitrev declares the new primary version to be acceptable and removes the old primary from
main memory (but not the hard disk).
A graceful upgrade takes a single card or a redundant card pair through different stages. Also, if you
must execute abortrev on a redundant pair, th e card (or possibly bo th cards in a redunda nt pair) are reset.
The stages of a graceful upgrade and th e reset actions appear in Tab le 2-1 0 for a single-card upgrade and
Table 2 -11 for a redundant-pair upgrade.
The tables start by showing that, ini tia ll y, the primary and secondary versions of firmwa re ar e 2. x, s o
the only possible operational version is 2.x. The loadrev command loads a generic version called 2 .y,
and the upgrade sequence prog re ssively ch an ge s th e primary and secondary firmware versi ons .
Note Of special note in Tabl e 2-11, runrev c au s es t he s ta ndby ca rd t o be co me t he ac tive card. The
reversed location of the “Active” and “Standby” columns shows the changed states.
Table2-10 Single-Card Upgrade From 2.x to 2.y
Firmware
Status Initial Version After loa drev After runrev After
commitrev
Primary 2.x 2.x 2.y 2.y
Secondary 2.x 2.y 2.x 2.y
Operational 2.x 2.x 2.y 2.y
After abortrev,
the card is reset.