Can persistent logging cause flash corruption?

[Garret Godfrey]

I've got a bunch of 2911 routers and recently turned on persistent logging to flash.  Since then, I've had a handful that have crashed and won't boot back up - while in rommon won't boot to the flash IOS. on some of my running routers, I saw the syslog folder had strange file names and negative file sizes. I used fsck flash: and got LFN/SFN entry corrupted. Marking entries (clus = CA41, off = 128)for recovery ...        Directory entries check ...[Failed]

Could it be that it's the persistent logging that's corrupting my flash?  While I find that it might be useful to see logs after a reload, the price is too high if it corrupts flash and hangs a reload.  Anyone else experience something similar?

[Leo Laohoo]

Why can't you get your logs to go to your TFTP server (instead of logging to the CF)?

[Garret Godfrey]

Leo,

We do have some off-site logging going on, but the idea was: If the circuit goes down, and later a local user power-cycles the router in an attempt to fix the issue, we still have visibility into the logs of what happened before the power-cycle.  The chance of needing it is low, but if we have the allocated space on the flash, why not?  Except, it looks like it is corrupting the flash in a number of cases...

[Leo Laohoo]

We do have some off-site logging going on, but the idea was: If the circuit goes down, and later a local user power-cycles the router in an attempt to fix the issue, we still have visibility into the logs of what happened before the power-cycle.  

You have TWO (2) choices: 

• If you have local logging, then you can use this; or
• You see those two USB slots?  *Wink*, *Wink*

Joking aside, depending on what brand your CF you are storing, I'd think about using USB.  The main trick is to get the right USB that the appliance can support or "recognize".  I always tell people in this forum that if you ever want to use USB, you go to your favorite/nearest electronics shop and buy a few VARIETY of USB sticks.  The size can be 2 Gb to 128 Gb.  You purchase (return the ones not working) different varieties to determine which one will work (and go back to buy more with the ones that work).  Stick the USB thumb drive and, if supported, use the appliance to format the USB thumb drive using the command "format usbflash0:".  

Alternatively, you can also configure the appliance to boot the IOS from a USB stick.