Hi, When an osd starts it should log at level 1 the min_alloc_size, see https://github.com/ceph/ceph/blob/master/src/os/bluestore/BlueStore.cc#L12260 grep "min_alloc_size 0x" ceph-osd.*.log Cheers, Dan On Thu, Feb 10, 2022 at 3:50 PM Scheurer François <francois.scheurer@xxxxxxxxxxxx> wrote: > > Hi everyone > > > How can we display the true osd block size? > > > I get 64K for a hdd osd: > > ceph daemon osd.0 config show | egrep --color=always "alloc_size|bdev_block_size" > "bdev_block_size": "4096", > "bluefs_alloc_size": "1048576", > "bluefs_shared_alloc_size": "65536", > "bluestore_extent_map_inline_shard_prealloc_size": "256", > "bluestore_max_alloc_size": "0", > "bluestore_min_alloc_size": "0", > "bluestore_min_alloc_size_hdd": "65536", > "bluestore_min_alloc_size_ssd": "16384", > > But it was explained that bluestore_min_alloc_size_hdd is only affecting newly created osd's. > So to check the current block size I can check the osd metadata and find 4K: > ceph osd metadata osd.0 | jq '.bluestore_bdev_block_size' > > "bluestore_bdev_block_size": "4096", > > Checking an object block size directly also shows 4K: > ceph-objectstore-tool --data-path /var/lib/ceph/osd/ceph-0 --pgid 6.5s4 "cb1594b3-a782-49d0-a19f-68cd48870a63.95398870.14_DriveE/Predator/Doc/2021/03/01101038/1523111.pdf.zip" dump | jq '.stat' > { > "size": 32768, > "blksize": 4096, > "blocks": 8, > "nlink": 1 > } > > So these hdd osd's were created with 4K block size without honoring bluestore_min_alloc_size_hdd? > The osd's are running on nautilus 14.2.5 and were created on luminous. > > Newer nvme osd's created on nautilus were also created with 4K without honoring bluestore_min_alloc_size_ssd (16K). > > This is confusing... Actually I would be happy with 4K as it is recommended to avoid over-allocation issue with EC pools. > But I would like to understand how to show the true block size of an existing osd... > > Many thanks for your help! ;-) > > > Cheers > Francois Scheurer > > > > > > > -- > > > EveryWare AG > François Scheurer > Senior Systems Engineer > Zurlindenstrasse 52a > CH-8003 Zürich > > tel: +41 44 466 60 00 > fax: +41 44 466 60 10 > mail: francois.scheurer@xxxxxxxxxxxx > web: http://www.everyware.ch > _______________________________________________ > 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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