Thank you for your reply.
Most of the NAND flash devices and HDDs have wear leveling and bad sector replacement algorithms
applied.
So I think that the life of the boot sector will not be exhausted first.
I'm not too worried about the life of the boot-sector.
I'm worried about write failures caused by external factors.
(power failure/system down/vibration/etc. during writing) They rarely occur on SD cards, but occur on
many HDDs, some SSDs and USB storages by 0.1% or more.
Hard disk and SSD do not guarantee atomic write of a sector unit?
In the case of SD, the sector-data will be either new or old when unexpected write interruption occurs.
Almost HDD, the sector-data will be either new, old, or unreadable.
And, some SSD products have similar problem.
Especially with AFT-HDD, not only boot-sector but also the following multiple sectors become
unreadable.
Other file systems will also be unstable on a such HW.
A well-designed FileSystems never rewrite critical regions.
It is not possible to completely solve this problem, as long as writing to the boot-sector.
(I think it's a exFAT's specification defect) The only effective way to reduce this problem is to
reduce writes to the boot-sector.
exFAT's specification defect... Well..
Even though the boot sector is corrupted, It can be recovered using the backup boot sector
through fsck.
Exactly.
However, in order to execute fsck, it is necessary to recognize the partition/volume with broken boot-sector as exfat.
Can linux(or fsck) correctly recognize the FileSystem even if the boot-sector cannot be read?
(I don't yet know how linux recognizes FileSystem)
In fact, a certain system recognize it as 'Unknown format'.
Nowadays, exfat is often used for removable storage.
This problem is not only for linux.
BR
---
etsuhiro Kohada <kohada.t2@xxxxxxxxx>
