cf card problem

one of cf card can’t boot,I found all the files in the diretory is lost,when i use “ls” i only can see “ÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿÿ”,what’s wrong?

sounds like it’s dead!, or maybe corrupt.
Can you do a chkfsys on the CF?

can anybody tell me what cause that?

Xuyong,

It could be the CF card just went bad.

It can also (more likely) be caused by someone powering off the computer while the CF card was writing to a file. CF cards take longer than harddrives to physically write to the medium so the chances of corruption are higher.

I VERY rarely write to my CF card for this reason. It’s much better to write temporary files to a RAM drive and only write extrement critical stuff to the CF card.

Tim

TIM,thanks a lot
unfortunately i have to record my data on the cf card and sent it to my server,now i save the data in one file(every time with the same filename),for the hardware engineer doesn’t design harddisk on the equipment.how can i write the data to a RAM file,i means the data exists as file on memory?is it possible?

devb-ram ram capacity=2048 disk name=ram
waitfor /dev/ram0t77
mount /dev/ram0t77 /ram

Note that capacity is in 512 byte (i.e. 0.5KB) chunks, so the “2048” is 1024KB = 1MB. Tailor to your app, obviously. The default is 4096.

The name “ram” is aribtrary.

After the mount, /ram works like any other disk / directory / block file system.

Then the problem becomes how and when do you copy from the ram drive to the flash drive. I’m afraid I don’t have a good answer for that one.

Hope that helps.

-James Ingraham
Sage Automation, Inc.

Ingraham,thanks
after mount /dev/ram0t77 /ram,then i can create the file just like
FILE*fp=fopen("/ram/test.dat",“w+”); and i can save data in it.Is it right?

Yes.

That makes twice I’ve helped someone! I’m on a roll! :smiley:

-James Ingraham
Sage Automation, Inc.

Xuyong,

Glad we can help. Just remember that a RAM drive is really and truly in memory only. So if QNX reboots, you’ll lose what was in the RAM drive. So if it’s VERY VERY critical you don’t lose the data on a reboot then the RAM drive isn’t the way to go.

On the plus side, RAM drives are much faster to read/write to than CF cards because it’s literally in memory. You can also ftp to/from the RAM drive with your remote server and you won’t use up the lifespan of the CF card.

Tim

thanks a lot :laughing: