I currently have LVM-cache set up on my Ubuntu install as described in https://rwmj.wordpress.com/2014/05/22/using-lvms-new-cache-feature/. (I did have to install some of the vivid/proposed packages to get it to work, but I managed.)
I was able to successfully convert one of my logical volumes into a cached volume, via:
# lvconvert --type cache --cachepool anson-TA75MH2/lv_cache anson-TA75MH2/root Logical volume anson-TA75MH2/root is now cached.
However, after doing this, I am unable to resize the cached partition.
When I try to extend the cached partition (in this case named
root, since it is going to be the root of my filesystem), I get an error message:
# lvextend anson-TA75MH2/root -L +250G Unable to resize logical volumes of cache type.
How can I turn the caching back off, so that I can resize it?
sda is my main 1TB hard drive, containing a large LVM partition and a shrunken ext4 partition that I plan to move into lvm. sdb is a cheap 32GB SSD, with a 500MB ext2 /boot partition, a big lvm partition, and 8GB of swap.
# vgs VG #PV #LV #SN Attr VSize VFree anson-TA75MH2 2 3 0 wz--n- 803.46g 499.96g # pvs PV VG Fmt Attr PSize PFree /dev/sda1 anson-TA75MH2 lvm2 a-- 782.47g 499.96g /dev/sdb2 anson-TA75MH2 lvm2 a-- 21.00g 0 # lvs LV VG Attr LSize Pool Origin Data% Meta% Move Log Cpy%Sync Convert home anson-TA75MH2 -wi-ao---- 250.47g lv_cache anson-TA75MH2 Cwi---C--- 20.96g root anson-TA75MH2 Cwi-aoC--- 32.00g lv_cache [root_corig]
Alternately, if there is a way to instead cache more than one LV using the same cache, that would be preferred (although I would still like to know how to turn it off). However, when I try it, it refuses:
# lvconvert --type cache --cachepool anson-TA75MH2/lv_cache anson-TA75MH2/home lv_cache is already in use by root