Hi guys, In the last days I tried to investigate how fio writes sequentially when using the libaio engine. As far as I understood, the key here is controlling the offset variable in the iocb struct (iocb->u.c.offset) so that the new block is written right next to the previous block.
Now a question comes to my mind. Even if fio is writing sequentially on a file or block, that does not guarantee that we are writing sequentially on the hard disk, right? I guess the linux kernel will be the one eventually deciding if that data is written sequentially or randomly across the disk. Nevertheless, I assume that when FIO writes sequentially to a file or block, the likelyhood that the data is written sequentially is increased. Is this correct? Do you know if there is a way from the user space (e.g. fio) to "force" the kernel to write sequentially? Thanks ofr your help! -- To unsubscribe from this list: send the line "unsubscribe fio" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
