ext4, fallocate, and InnoDB autoincrement

This might be a bit cutting edge, but the new fallocate() call in > Linux 2.6.23 might be able to improve InnoDB performance.

When InnoDB needs more space it auto-extends the current data file by 8MB. If this is writing out zeros to the new data (to initialize it) then using fallocate() would certainly be faster.

Apparently, XFS supports this too but needs an ioctl. XFS could support fallocate in the future as well…


  1. XFS has supported it forever – and I put this into NDB a good number of year ago now.

    The kernel patch to have XFS support for fallocate() I believe was also in there since day 1 (of the fallocate code making it into Linus’ tree)






%d bloggers like this: