Lakshmi
2015-09-28 18:11:30 UTC
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
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
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