Is It True about NVRAM
Is It True ?
NVRAM is a partition of Flash memory in all Cisco devices. They are not seperate chips.
Although this picture may show that, it's only for discussion to make sure that you know that NVRAM and FLASH are used for completely different reasons.
reason I ask is because I remember seeing a topic where someone had
purchased a router from ebay. They did a basic power on test when the
receive it to make sure it booted properly then set it aside for a
Later, when they were ready to put it
into service in their Lab Rack, they found it would not allow them to
save the config to NVRAM. Attempts at copy run start or wr received a
""NVRAM Verification Failed" error.
the the link below, there were actually 2 2650XM routers. According to
this thread, it appears that someone harvested the nvram chips at some
point prior to the vendor shipping the routers to this person. Once they
addressesd this with the vendor, replacement chips we sent and
installed and problems solved.
have not looked into this further, but I suspect that all the
2600/2600XM series are the same. I also know that I can remove the CF
(Flash Card) from my 2811 and 2821 and still be able to write config
changes to nvram without throwing an error. When I reboot, with the
flash card re-installed, it reloads with the config saved just prior to
reboot (confirmed while writing this post).
I think back about the various flash memory upgrades I have done with
routers I own or purchased and sold, 2600 series, 3600 series, and
1760s, I never lost an existing config when changing flash memory
modules. If, as you say, "NVRAM is a partition of Flash memory in all
Cisco devices. They are not seperate chips." then any configurations
stored on that partition on the flash module would move with the module
(much the same as removing a HD containing partitions from a PC and
replacing it with a HD with completely different partitions) and not
remain on the router!
From this, I think you may understand my confusion and thus my question.