hi,
i played around with the io limiting for the disk. we have server with local storage and also ceph cluster.
when i limit the disk for example to 500 iops i get around 2mb with 4K reads/writes what is exactly 500 iops.
but with 4M blocks i get only a speed of 65M/sec which is far below that.
it is impossible for me to limit a vm to specs of a sata disk (around 120 iops and 130MB/sec) because if i will have 130mb/sec sequential i need around 1000 iops- or if i limit the iops to 120 i will get far below (around 35Mb/sec) seq read/writes
btw. i could not experience a difference with the burst_iops. i set them to numbers like 100000 and it made no difference even for small writes.
greetings
i played around with the io limiting for the disk. we have server with local storage and also ceph cluster.
when i limit the disk for example to 500 iops i get around 2mb with 4K reads/writes what is exactly 500 iops.
but with 4M blocks i get only a speed of 65M/sec which is far below that.
it is impossible for me to limit a vm to specs of a sata disk (around 120 iops and 130MB/sec) because if i will have 130mb/sec sequential i need around 1000 iops- or if i limit the iops to 120 i will get far below (around 35Mb/sec) seq read/writes
btw. i could not experience a difference with the burst_iops. i set them to numbers like 100000 and it made no difference even for small writes.
greetings