# Requirements for using torn write prevention on Amazon EC2
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For torn write prevention to work properly, an I/O operation must meet size, alignment, and boundary requirements, as specified in the `NTWPU`, `NTWGU`, `NTWBU` fields. You must configure your operating system to ensure that the specific storage subsystem (file system, LVM, RAID, etc) does not modify I/O properties down the storage stack, including block merges, splits, or block address relocation, before being submitted to the device.

Torn write prevent has been tested with the following configuration:
+ An instance type and storage type that supports the required block size.
+ Amazon Linux 2 with kernel version 5.10 or later.
+ ext4 with `bigalloc` enabled and a cluster size of 16 KiB, and the most recent ext4 utilities (e2fsprogs 1.46.5 or later).
+ `O_DIRECT` file access mode to bypass Linux kernel buffer cache.

**Note**  
You do not need to disable I/O merging for MySQL and MariaDB workloads.