Question about partitioning (partition /dev/mtdblock0)

[rbourgeon]

Hello,
I have a pool of several hundreds of LMs. I've noticed that on most of them, there are only 4 partitions:

• /dev/root (mounted on /)
  
• tmpfs (mounted on /tmp)
  
• tmpfs (mounted on /dev)
  
• /dev/mmcblk0p3 (mounted on /data)
  

However, on a minority of my LMs, I've noticed the presence of a 5th partition: /dev/mtdblock0, mounted on /data/storage/db. The size of this partition is always 32 MB, and this partition looks critical because it contains the database of the LogicMachine.

Can you explain to me why this partition sometimes exists and sometimes doesn't? Which action leads to this partition being created?

[Daniel]

During some time we were manufacturing HW with extra SPI flash for extra reliability as we had issue with SD cards. For some time now we are using much better cards and the SPI is not used anymore as there is no sense as card is same quality or even better than SPI.