Hi, Thanks a lot for the information. I have a last question. Why is the bench performed using writes of 4 KiB. Is any reason to choose that over another another value? On my lab, I tested with various values, and I have mainly two type of disks. Some Seagates and Toshiba. If I do bench with 4KiB, what I get from Seagate is a result around 2000 IOPS. While the Toshiba is more arround 600. If I do bench with 128KiB, I still have results arround 2000 IOPS for Seagate, but Toshiba also bench arround 2000 IOPS. And from the rados experiment I did, having osd_mclock_max_capacity_iops_hdd set to 2000 on that lab setup is the value I get the most performance from my rados experiments, both with Segate and Toshiba disks. Luis Domingues Proton AG ------- Original Message ------- On Monday, April 3rd, 2023 at 08:44, Sridhar Seshasayee <sseshasa@redhat.com> wrote:
Why was it done that way? I do not understand the reason why distributing
the IOPS accross different disks, when the measurement we have is for one disk alone. This means with default parameters we will always be far from reaching OSD limit right?
It's not on different disks. We distribute the IOPS across shards on a
given OSD/disk. This is an internal implementation detail. This means in your case, 450 IOPS is distributed across 5 shards on the same OSD/disk. You can think of it as 5 threads being allocated a share of the total IOPS on a given OSD. -Sridhar _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io