Thanks for the prompt response! I see, and indeed some of them are consumer SSD disks. Is there any parameter that we can change/tune to better handle the call "fdatsync"? Maybe using NVMEs for the RocksDB? On Thu, Feb 22, 2024 at 2:24 PM Mark Nelson <mark.nelson@xxxxxxxxx> wrote: > Most likely you are seeing time spent waiting on fdatsync in > bstore_kv_sync if the drives you are using don't have power loss > protection and can't perform flushes quickly. Some consumer grade > drives are actually slower at this than HDDs. > > > Mark > > > On 2/22/24 11:04, Work Ceph wrote: > > Hello guys, > > We are running Ceph Octopus on Ubuntu 18.04, and we are noticing spikes > of > > IO utilization for bstore_kv_sync thread during processes such as adding > a > > new pool and increasing/reducing the number of PGs in a pool. > > > > It is funny though that the IO utilization (reported with IOTOP) is > 99.99%, > > but the reading for R/W speeds are slow. The devices where we are seeing > > these issues are all SSDs systems. We are not using high end SSDs devices > > though. > > > > Have you guys seen such behavior? > > > > Also, do you guys have any clues on why the IO utilization would be high, > > when there is such a small amount of data being read and written to the > > OSD/disks? > > _______________________________________________ > > ceph-users mailing list -- ceph-users@xxxxxxx > > To unsubscribe send an email to ceph-users-leave@xxxxxxx > > -- > Best Regards, > Mark Nelson > Head of Research and Development > > Clyso GmbH > p: +49 89 21552391 12 | a: Minnesota, USA > w: https://clyso.com | e: mark.nelson@xxxxxxxxx > > We are hiring: https://www.clyso.com/jobs/ > _______________________________________________ > 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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