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@xxxxxxxxxx> 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@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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