As a followup to Replicating an SD card:

If using the commands

  1. dd or
  2. `cat'

as prescribed in the responses, does this remove the need to format the SD card?


Formatting an sdcard usually involves creating a partition table and then a filesystem.

If you're making a copy of the whole device (or partition), then the destination will be formatted the same way as the source, removing the need to format it again.

There is one caveat—the destination filesystem will have the same UUID as the source. Depending on the filesystem, this could cause data loss (see Btrfs).

Filesystems such as Btrfs, ext4, etc, have specific tools for changing the UUID afterwards (such as btrfstune or tune2fs.)


dd clones it block by block at the block level. No need to format. Formatting is at file system level. The block level is very low level.

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