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Hi, I am starting with investigating about the lvm thin provisioning (apologies for html mail) I have done the following 1.Create a PV vdb 252:16 0 10G 0 disk ├─vdb1 252:17 0 100M 0 part └─vdb2 252:18 0 9.9G 0 part root@vmm-deb:~# pvcreate /dev/vdb1 Physical volume "/dev/vdb1" successfully created. root@vmm-deb:~# pvs PV VG Fmt Attr PSize PFree /dev/vdb1 lvm2 --- 100.00m 100.00m 2. create a VG root@vmm-deb:~# vgcreate virtp /dev/vdb1 Volume group "virtp" successfully created root@vmm-deb:~# vgs VG #PV #LV #SN Attr VSize VFree virtp 1 0 0 wz--n- 96.00m 96.00m 3. create a lv pool and a over-provisioned volume inside it root@vmm-deb:~# lvcreate -n virtpool -T virtp/virtpool -L40M Logical volume "virtpool" created. root@vmm-deb:~# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert virtpool virtp twi-a-tz-- 40.00m 0.00 0.88 root@vmm-deb:~# lvcreate -V1G -T virtp/virtpool -n vol01 WARNING: Sum of all thin volume sizes (1.00 GiB) exceeds the size of thin pool virtp/virtpool and the size of whole volume group (96.00 MiB)! For thin pool auto extension activation/thin_pool_autoextend_threshold should be below 100. Logical volume "vol01" created. root@vmm-deb:~# lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert virtpool virtp twi-aotz-- 40.00m 0.00 0.98 vol01 virtp Vwi-a-tz-- 1.00g virtpool 0.00 ---------- Now the operations # dd if=/dev/urandom of=./fil status=progress 90532864 bytes (91 MB, 86 MiB) copied, 6.00005 s, 15.1 MB/s^C 188706+0 records in 188705+0 records out 96616960 bytes (97 MB, 92 MiB) copied, 6.42704 s, 15.0 MB/s # df -h . Filesystem Size Used Avail Use% Mounted on /dev/mapper/virtp-vol01 976M 95M 815M 11% /tmp/x # sync # cd .. root@vmm-deb:/tmp# umount x root@vmm-deb:/tmp# fsck.ext4 -f -C0 /dev/virtp/vol01 e2fsck 1.43-WIP (15-Mar-2016) Pass 1: Checking inodes, blocks, and sizes Pass 2: Checking directory structure Pass 3: Checking directory connectivity Pass 4: Checking reference counts Pass 5: Checking group summary information /dev/virtp/vol01: 12/65536 files (8.3% non-contiguous), 36544/262144 blocks <mount> # du -hs fil 93M fil # dd if=./fil of=/dev/null status=progress 188705+0 records in 188705+0 records out 96616960 bytes (97 MB, 92 MiB) copied, 0.149194 s, 648 MB/s # vgs VG #PV #LV #SN Attr VSize VFree virtp 1 2 0 wz--n- 96.00m 48.00m What i expect is that the pool is 40M and the file must NOT exceed 40M. Where does the file get 93M space ? I know the VG is 96M but the pool created was max 40M (also VG still says 48M free). Is the file exceeding the boundaries ? or am I doing anything wrong ? -- Bhasker C V Secure Mails: http://pgp.mit.edu/pks/lookup?op=get&search=0x4D05FEEC54E47413 Registered Linux User: #306349 |