Ted, > It's true that relative to not doing checksumming at all, it it's not > "free". The CPU has to calculate the checksum, so there are power, > CPU, and memory bandwidth costs. I'd still tend to lean towards > defaulting it to on, so that the user doesn't need do anything special > if they have hardware is capable of supporting the data integrity > feature. It already works that way. If a device advertises being integrity-capable, the block layer will automatically generate protection information on write and verify received protection information on read. Leveraging hardware-accelerated CRC calculation if the CPU is capable (PCLMULQDQ, etc.). -- Martin K. Petersen Oracle Linux Engineering
