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High NTFS fragmentation, and IO error was reported by on stackexchange
https://dba.stackexchange.com/questions/186895/ntfs-filesystem-fragmentation-issue-occur-after-migrating-mysql-5-6-database-to
This is for 10.2. There are 2 things that have changed as compared with to previous version
- all files are made sparse "when opening", this was ported from Innodb 5.7
- when tablespace is extended, we do not write binary zeros anymore to the file, but instead
SetFileInformationByHandle with FileEndOfFileInfo
Together, those changes might create a "hole" at the end of file, even if compression is not on. Also some investigation should be done on whether to write binary zeroes is necessary, and on how exactly to grow file. There are several options - write zeroes, SetEndOfFile, SetFileInformationByHandle(), DeviceIoControl(FSCTL_SET_ZERO_RANGE) . Some details can be found in https://stackoverflow.com/questions/46458151/setendoffile-vs-setfileinformationbyhandle-to-extend-file)
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