Be careful when you are designing, if you are planning to have billions of objects, you need to have more than 2-4% for rocksdb+wal to avoid spillover. Istvan Szabo Senior Infrastructure Engineer --------------------------------------------------- Agoda Services Co., Ltd. e: istvan.szabo@xxxxxxxxx<mailto:istvan.szabo@xxxxxxxxx> --------------------------------------------------- On 2021. Oct 22., at 14:47, Peter Sabaini <peter@xxxxxxxxxx> wrote: Email received from the internet. If in doubt, don't click any link nor open any attachment ! ________________________________ On 22.10.21 11:29, Mevludin Blazevic wrote: Dear Ceph users, I have a small Ceph cluster where each host consist of a small amount of SSDs and a larger number of HDDs. Is there a way to use the SSDs as performance optimization such as putting OSD Journals to the SSDs and/or using SSDs for caching? Hi, yes, SSDs can be put to good use as journal devices[0] for OSDs, or you could use them as caching devices for bcache[1]. This is actually a pretty widespread setup, theres docs for various scenarios[2][3] But be aware that OSD journals are pretty write-intense, so be sure to use fast, reliable SSDs (or NVMes). I have actually seen OSD performance (esp. latency and jitter) actually worsen with (prosumer-grade) SSDs that could not support the sustained write load. If at all in doubt run tests before putting prod on it [0] https://docs.ceph.com/en/latest/start/hardware-recommendations/ [1] https://bcache.evilpiepirate.org/ [2] https://charmhub.io/ceph-osd [3] https://access.redhat.com/documentation/en-us/red_hat_ceph_storage/4/html/object_gateway_for_production_guide/using-nvme-with-lvm-optimally Best regards, Mevludin _______________________________________________ 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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