I think this would be a great place in the ML to look. https://ceph-users.ceph.narkive.com/AthYx879/ceph-volume-migration-and-disk-partition-support <https://ceph-users.ceph.narkive.com/AthYx879/ceph-volume-migration-and-disk-partition-support> Reed > On Mar 19, 2021, at 2:17 PM, Marc <Marc@xxxxxxxxxxxxxxxxx> wrote: > > I have asked exactly the same question 1 year ago or so. Sage told me to show evidence of a significant impact, because they did not measured one. > > If I remember correctly is the idea behind this that not all storage devices are available as /dev/sdX as normal disk and lvm sort of solves this problem. (Maybe related to some nvme devices) > > Maybe you can search for it in the mailing list ;) > > >> -----Original Message----- >> From: Nico Schottelius <nico.schottelius@xxxxxxxxxxx> >> Sent: 19 March 2021 20:12 >> To: ceph-users <ceph-users@xxxxxxx> >> Subject: LVM vs. direct disk acess >> >> >> Good evening, >> >> I've seen the shift in ceph to focus more on LVM than on plain (direct) >> access to disks. I was wondering what the motivation is for that. >> >> From my point of view OSD disk layouts never change (they are re-added >> if they do), so the dynamic approach of LVM is probably not the >> motivation. >> >> LVM also adds another layer of indirection and it seems it would be of >> disadvantage performance wise as well as added complexity for >> management. The former is probably only a minor degradation, the latter >> is something I see more as obstacle for maintenance. >> >> At ungleich we are using a custom script [0] to format a disk with two >> partitions, one for the metadata, one for the rest, which seems to be >> more simple. >> >> I assume there are good reasons not to do as we do, but I was wondering >> what the practical reasons actually are. >> >> Best regards, >> >> Nico >> >> [0] https://code.ungleich.ch/ungleich-public/ungleich-tools/- >> /blob/master/ceph/ceph-osd-create-start >> >> -- >> Sustainable and modern Infrastructures by ungleich.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 _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
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