----- Le 28 Juin 24, à 15:27, Anthony D'Atri anthony.datri@gmail.com a écrit :
But this in a spec doesn't match it:
size: '7000G:'
This does:
size: '6950G:'
There definitely is some rounding within Ceph, and base 2 vs base 10 shenanigans.
$ cephadm shell ceph-volume inventory /dev/sdc --format json | jq .sys_api.human_readable_size "3.64 TB"
Ceph like humans thinks in terms of base 2 units, e.g. GiB and TiB. Storage manufacturers are, well, mustelids and almost always express in terms of base 10 units, GB and TB, because they read as slightly higher.
The 'size:' spec you set is in GB (only GB and MB are supported). However, ceph-volume inventory output can use other units (TB in this example). Therefore, the orchestrator first converts both values to bytes. Since the ceph-volume inventory produces a figure with only 2 decimals and the conversion uses powers of 10 (1e+9 for GB, 1e+12 for TB), the matching size here would be "size: 3640GB". This was confirmed by my testing a few months ago.
If my understanding is correct, it may be worth adding to the doc [2] that the device size is human_readable_size in TB from ceph-volume inventory x 10 GB.
Please enter a tracker ticket for this with details and tag me. Do you mean x1000 not x10?
Of course x1000. ;-) Here's the tracker: https://tracker.ceph.com/issues/66754 Frédéric.
Regards, Frédéric.
[1] https://github.com/ceph/ceph/blob/main/src/python-common/ceph/deployment/dri... [2] https://docs.ceph.com/en/latest/cephadm/services/osd/
Mvh.
Torkil
-- Torkil Svensgaard Sysadmin MR-Forskningssektionen, afs. 714 DRCMR, Danish Research Centre for Magnetic Resonance Hvidovre Hospital Kettegård Allé 30 DK-2650 Hvidovre Denmark Tel: +45 386 22828 E-mail: torkil@drcmr.dk _______________________________________________ ceph-users mailing list -- ceph-users@ceph.io To unsubscribe send an email to ceph-users-leave@ceph.io
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