Hi, i am currently trying to make a more or less smart decision what HDD's will be used for the cold storage behind the ssd cache tier. As i saw, there are lately different drives available: 512N ( 512 bytes native sector size ) 512E ( 512 bytes emulated on 4k sector size ) 4kN ( 4k native sector size ) So the question is, if anyone has any experience with that in terms of performance. For me, in my current deployment, i have: osd_mkfs_options_xfs = -f -i size=2048 Which will generate a secorsize of 2048 bytes, which will be suboptimal or maybe even not working with the 4kN drives. So, especially for ceph, what is better, bigger sectorsizes like 4k ? especially when working with a 4kN drive ? >From what i see within ceph on my xfs drives, most ( all ?! ) files are 4194304 bytes long, so about 4 MB blocks. So a Blocksize of 4k would be fine with that i think. Or better smaller sectorsizes ? ##################################### And about choosing drives: So far there are this options for me, for now: - MG04SCA40EA: Toshiba 3.5" 4TB SAS 12Gb/s 7.2K RPM 128M 4Kn (Tomcat R) - HUS726040AL4210: HGST 3.5" 4TB SAS 12Gb/s 7.2K RPM 128M 0F22794 4kn ISE (Aries KP) - ST4000NM0014: Seagate 3.5" 4TB SAS 12Gb/s 7.2K RPM 128M Makara (4kN) This drives are also available in 512E versions. Anyone has any experience with any of that drives ? Any input is welcome. Thank you ! -- Mit freundlichen Gruessen / Best regards Oliver Dzombic IP-Interactive mailto:info@xxxxxxxxxxxxxxxxx Anschrift: IP Interactive UG ( haftungsbeschraenkt ) Zum Sonnenberg 1-3 63571 Gelnhausen HRB 93402 beim Amtsgericht Hanau Geschäftsführung: Oliver Dzombic Steuer Nr.: 35 236 3622 1 UST ID: DE274086107 _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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