Yes, would be interesting. I understood that it mainly helps with buffered writes, but ceph is using direct IO for writes and that's where bypassing the queues helps. Are there detailed instructions somewhere how to set up a host to disable the queues? I don't have time to figure this out myself. It should be detailed enough so that I just need to edit some configs, reboot et voila. I have a number of new hosts to deploy and I could use one of these to run a test. They have a mix of NVMe, SSD and HDD and I can run fio benchmarks before deploying OSDs in the way you did. Thanks and best regards, ================= Frank Schilder AIT Risø Campus Bygning 109, rum S14 ________________________________________ From: Stefan Kooman <stefan@xxxxxx> Sent: Tuesday, June 6, 2023 3:20 PM To: Frank Schilder; Anthony D'Atri; ceph-users@xxxxxxx Subject: Re: Re: Encryption per user Howto On 6/6/23 14:26, Frank Schilder wrote: > Hi Stefan, > > there are still users with large HDD installations and I think this will not change anytime soon. What is the impact of encryption with the new settings for HDD? Is it as bad as their continued omission from any statement suggests? We only tested flash, as we don't have any spinners to test on. So not sure what the impact would be. From the blog post I got that the queuing was there to mainly help workloads with spinning disks. But all that was valid in 2015. It specifically mentions benefit for CFQ scheduler, that since has been removed from the linux kernel. So, it would be interesting to know if it is still needed on spinners when used with Ceph ... Gr. Stefan _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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