just curious about this: > Worth to note there is fixed strict limit of the ~16GiB maximum > thin-pool kernel metadata size - which surely can be exhausted - > mapping holds info about bTree mappings and sharing chunks between > devices.... would that mean that one single thin-pool can maximum hold 16GiB/16 nr of blocks? and how about if LVM2 uses VDO as backend, are there more limitations that I need to consider there that are not reflected here Sent from my iPhone > On 16 Sep 2020, at 00:26, Gionatan Danti <g.danti@xxxxxxxxxx> wrote: > > Il 2020-09-15 23:47 Zdenek Kabelac ha scritto: >> You likely don't need such amount of 'snapshots' and you will need to >> implement something to remove snapshot without need, so i.e. after a >> day you will keep maybe 'every-4-hour' and after couple days maybe >> only a day-level snapshot. After a month per-week and so one. > > Agree. "Snapshot-thinning" is an essential part of snapshot management. > >> Speaking of thin volumes - there can be at most 2^24 thin devices >> (this is hard limit you've ask for ;)) - but you have only ~16GiB of >> metadata to store all of them - which gives you ~1KiB of data per such >> volume - >> quite frankly this is not too much - unless as said - your volumes >> are not changed at all - but then why you would be building all this... >> That all said - if you really need that intensive amount of snapshoting, >> lvm2 is likely not for you - and you will need to build something on your own, >> as you will need way more efficient and 'targeted' solution for your purpose. > > Thinvols are not activated by default - this means it should be not a big problem managing some hundreds of them, as the OP ask. Or am I missing something? > > Regards. > > -- > Danti Gionatan > Supporto Tecnico > Assyoma S.r.l. - www.assyoma.it > email: g.danti@xxxxxxxxxx - info@xxxxxxxxxx > GPG public key ID: FF5F32A8 _______________________________________________ linux-lvm mailing list linux-lvm@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
