Comment on Redis with an SSD swap – not what you wantparentComments−finnh13yI don't understand the utility of your homegrown metric.Yes, a 7K disk can output 160MB/s ... if it's doing a continous read, with zero seeks per second.If it's actually doing 160 seeks/second, it's not going to have time to read 1MB (taking a further 1/160th of a second) after each seek.So this metric means "how much data you can read per iop if you want to cut your iops by about 50%".How is that useful above & beyond the input numbers?
Comments
I don't understand the utility of your homegrown metric.
Yes, a 7K disk can output 160MB/s ... if it's doing a continous read, with zero seeks per second.
If it's actually doing 160 seeks/second, it's not going to have time to read 1MB (taking a further 1/160th of a second) after each seek.
So this metric means "how much data you can read per iop if you want to cut your iops by about 50%".
How is that useful above & beyond the input numbers?