[linux-lvm] [PATCH] man: document that 2 times poolmetadatasize is allocated for lvmthin
diff --git a/man/lvmthin.7_main b/man/lvmthin.7_main index ce2343183..e21e516c9 100644 --- a/man/lvmthin.7_main +++ b/man/lvmthin.7_main @@ -1101,6 +1101,11 @@ specified with the --poolmetadatasize option. When this option is not given, LVM automatically chooses a size based on the data size and chunk size. +The space allocated by creation of a thinpool will include +a spare metadata LV by default (see "Spare metadata LV"). As a result, +the VG must have enough space for the --size option plus twice +the specified (or calculated) --poolmetadata value. + It can be hard to predict the amount of metadata space that will be needed, so it is recommended to start with a size of 1GiB which should be enough for all practical purposes. A thin pool metadata LV can later be ___ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
Re: [linux-lvm] Why does thinpool take 2*poolmetadatasize space?
Dne 20. 10. 20 v 18:33 Scott Moser napsal(a): When I create an lvmthinpool with size S and poolmetadatasize P, it reduces the available freespace by S+2P. I expected that to be S+P. Where did the extra poolmetadatasize get used? See below for example. before lvcreate we had 255868 free, after we had 254588. The difference is 1280. (1024 + 2*128). lvm2 preallocated hidden _pmspare volume which has the size of biggest metadata LV in a VG. Such LV is used for automated 'lvconvert --repair'. If you don't want this LV to be created you can add --poolmetadataspare y|n but in this case you are fully in your own to figure out, where to take the space for repaired metadata. You can also at any time lvremove _pmspare LV if necessary. Regards Zdenek ___ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
[linux-lvm] Why does thinpool take 2*poolmetadatasize space?
When I create an lvmthinpool with size S and poolmetadatasize P, it reduces the available freespace by S+2P. I expected that to be S+P. Where did the extra poolmetadatasize get used? See below for example. before lvcreate we had 255868 free, after we had 254588. The difference is 1280. (1024 + 2*128). # lvm vgcreate --metadatasize=128m myvg0 /dev/vda Physical volume "/dev/vda" successfully created. Volume group "myvg0" successfully created # pvs --unit=m PV VGFmt Attr PSize PFree /dev/vda myvg0 lvm2 a-- 255868.00m 255868.00m # vgs --unit=m VG#PV #LV #SN Attr VSize VFree myvg0 1 0 0 wz--n- 255868.00m 255868.00m # lvm lvcreate --ignoremonitoring --yes --activate=y \ --setactivationskip=n --size=1024m --poolmetadatasize=128m \ --thinpool=mythinpool myvg0 Thin pool volume with chunk size 64.00 KiB can address at most 15.81 TiB of da ta. Logical volume "mythinpool" created. # vgs --unit=m VG#PV #LV #SN Attr VSize VFree myvg0 1 1 0 wz--n- 255868.00m 254588.00m # lvs --all --unit=m LV VGAttr LSizePool Origin Data% Meta% Move Log Cpy%Sync Convert [lvol0_pmspare]myvg0 ewi--- 128.00m mythinpool myvg0 twi-a-tz-- 1024.00m 0.00 10.03 [mythinpool_tdata] myvg0 Twi-ao 1024.00m [mythinpool_tmeta] myvg0 ewi-ao 128.00m ___ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
