"The super block is stored in two 4KB blocks at a known location at the start of the device." There should be more than 2 slots for the super block, e.g. at le

"The super block is stored in two 4KB blocks at a known location at the start of the device." There should be more than 2 slots for the super block, e.g. at least 64 slots for the super block, to allow for better wear-leveling for SSDs. AFAIK this has been a problem for some filesystems, which wear out the device due to the high frequency of super block updates. The latest super block should also be replicated 2-4 times on disk to survive corruption. Otherwise, the loss of a mere two contiguous disk sectors could result in loss of the entire disk. A super block of 4KB also looks like they might be relying too much on the device to guarantee atomic sector writes (this is almost always the case, but not necessarily), instead of using a cryptographic signature to verify that the super block was written atomically. Also, 4KB seems small these days for a super block, especially if the super block needs to include replicated information relating to RAID sibling devices etc.