Shadow copies of the EXT2 superblock

[eryjus]

I apologize for the silly question. I have been studying the following document: http://www.nongnu.org/ext2-doc/ext2.pdf

With the introduction of revision 1 and the sparse superblock feature in Ext2, only specific block groups contain copies of the superblock and block group descriptor table. All block groups still contain the block bitmap, inode bitmap, inode table, and data blocks. The shadow copies of the superblock can be located in block groups 0, 1 and powers of 3, 5 and 7.

For whatever reason, I am not confident in my own brain today.... "... power of 3 ..." is stating "N cubed, where N == 1, 2, 3, 4, 5, ...", NOT "N * 3".

Also, my calculations tell me that there is a theoretical maximum of 262,144 block groups (2,147,483,647 / 8,192 for 1K blocks [rounded up]).

My brain tells me that my thinking above is correct, but something is nagging at me I cannot put a finger on.... Can someone please check my thinking above?


Thanks!!

EDIT: .... OR .... should I be thinking "3 to the power of N, where N == 1, 2, 3, 4, 5, etc..."

[gerryg400]

Power of 3 means 3, 9, 27, 81, 243, 729 .... etc.
Power of 5 means 5, 25, 125, 625 .... etc.
Power of 7 means 7, 49, 343 ... etc.

Which gives 0, 1, 3, 5, 7, 9, 25, 27, 49, 81, 125, 243, 343, 625, 729 ... etc.

[eryjus]

Which gives 0, 1, 3, 5, 7, 9, 25, 27, 49, 81, 125, 243, 343, 625, 729 ... etc.

Thank you so much!!!