Hi all, I am hoping to get some answers, pointers here as I am stuck with this for quite sometime and need some suggestions to proceed further. I am using lvm-cache for my test and My current test setup has, 1x1142GB HDD in Raid0 1x387GB SSD in Raid 0 I have RHEL 7.1 and 3.10.0-229.el7.ppc64. lvm version that was part of the distro LVM version: 2.02.115(2)-RHEL7 (2015-01-28) Library version: 1.02.93-RHEL7 (2015-01-28) Driver version: 4.29.0 pvscan looks like this. # pvscan PV /dev/sdi1 lvm2 [1.04 TiB] PV /dev/sdh1 lvm2 [361.31 GiB] Steps I followed to create the lvm-cache device 1. Created a partition on entire HDD and a partition on entire SSD 2. Created physical volumes for the above partitions 3. Created Volume Group using these 2 PVs 4. Created LVMS as follows Create Origin Device logical Volume (origin_device) lvcreate -L 1024G -n origin_device cache_VG /dev/sdu1 Create a cache meta data logical Volume (cache_meta) lvcreate -L 315M -n Cache_Meta Cache_VG /dev/sdw1 >>> used 1/1000(307G) as mentione din lvm-cache manpage Create a cache block data logical Volume (cache_block) lvcreate -L 307G -n Cache_Block Cache_VG /dev/sdw1 Create a cache pool logical volume by combining cache block and cache meta data logical volumes (combining step 5 and 6) lvconvert --type cache-pool --cachemode writeback --poolmetadata Cache_VG/Cache_Meta Cache_VG/Cache_Block ISSUE: And I get WARNING: Maximum supported pool metadata size is 16.00 GiB. WARNING: Converting logical volume Cache_VG/Cache_Meta and Cache_VG/Cache_Block to pool's data and metadata volumes. THIS WILL DESTROY CONTENT OF LOGICAL VOLUME (filesystem etc.) Do you really want to convert Cache_VG/Cache_Meta and Cache_VG/Cache_Block? [y/n]: y Volume group "Cache_VG" has insufficient free space (24077 extents): 78592 required. QUESTION: Can someone tell me why it complains that it doesnt have enough space, since the LVMS are already carved from the Volume group and all it does is convert to a cachepool? I am not aware of the intrenal details of converting a cache pool, but if somebody could tell me the reason or how i can fix this , it would be very helpful. This is my "vgdisplay" output --- Volume group --- VG Name Cache_VG System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 4 VG Access read/write VG Status resizable MAX LV 0 Cur LV 3 Open LV 0 Max PV 0 Cur PV 2 Act PV 2 VG Size 1.39 TiB PE Size 4.00 MiB Total PE 364892 Alloc PE / Size 340815 / 1.30 TiB Free PE / Size 24077 / 94.05 GiB # pvdisplay /dev/sdh1 --- Physical volume --- PV Name /dev/sdh1 VG Name Cache_307GB_VG PV Size 361.31 GiB / not usable 3.00 MiB Allocatable yes PE Size 4.00 MiB Total PE 92495 Free PE 13824 Allocated PE 78671 # pvdisplay /dev/sdi1 --- Physical volume --- PV Name /dev/sdi1 VG Name Cache_307GB_VG PV Size 1.04 TiB / not usable 3.00 MiB Allocatable yes PE Size 4.00 MiB Total PE 272397 Free PE 10253 Allocated PE 262144 Any suggestions , pointers will be really helpful as I am stuck with this for sometime and I have not been able to proceed. Thanks, ld _______________________________________________ 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/
