We are using 4TB Kingston DC500M drives for 6+2 EC RBD data pools, 2 OSDs per disk. They deliver great iops, but I think they are TLC, so probably not comparable with QLC drives. I think QLC drives are OK for mostly cold/static data due to their performance drop when running full: https://www.howtogeek.com/428869/ssds-are-getting-denser-and-slower-thanks-to-qlc-flash/
For certain applications, the low bandwidth when full might be acceptable. They still deliver significantly more iops than HDD. For example, on our RBD pools, the average bandwidth per drive is below 50MB/s. So, a drop to max 80MB/s is acceptable under normal operations. Just don't expect great rebuild-times when bandwidth starts becoming the limit. I consider using large flash drives for our ceph FS data pool in the long run. We are approaching 1000 OSDs on that pool and have mostly cold data. A further benefit is no moving parts. The higher shock resistance can be a big plus. Best regards, ================= Frank Schilder AIT Risø Campus Bygning 109, rum S14 ________________________________________ From: Matt Larson <larsonma...@gmail.com> Sent: 07 May 2021 22:10:40 To: ceph-users Subject: [ceph-users] Building ceph clusters with 8TB SSD drives? Is anyone trying Ceph clusters containing larger (4-8TB) SSD drives? 8TB SSDs are described here ( https://www.anandtech.com/show/16136/qlc-8tb-ssd-review-samsung-870-qvo-sabrent-rocket-q ) and make use QLC NAND flash memory to reach the costs and capacity. Currently, the 8TB Samsung 870 SSD is $800/ea at some online retail stores. SATA form-factor SSDs can reach read/write rates of 560/520 MB/s, while not as great as nVME drives is still a multiple faster than 7200 RPM drives. SSDs now appear to have much lower failure rates than HDs in 2021 ( https://www.techspot.com/news/89590-backblaze-latest-storage-reliability-figures-add-ssd-boot.html ). Are there any major caveats to considering working with larger SSDs for data pools? Thanks, Matt -- Matt Larson, PhD Madison, WI 53705 U.S.A. _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-le...@ceph.io _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-le...@ceph.io
