[linux-lvm] howto cache a thinpool-device?

[Oliver Rath]

Hi list,

Im playing around with the new cache options. Ive created a lvm-device
on my cache-disk named lvx-cache (vg is dmivg). Additionally Ive created
a thinpool-device named winthinpool.

Now i wanted to use my cache-device to cache my thinpool-lvm, but this
doesnt work:

~# lvconvert --type cache --cachepool dmivg/lvx_cache dmivg/winthinpool
Can't cache thin-pool volume dmivg/winthinpool.

isnt is possible to cache a thinpool-device?

Tfh!
Oliver

[Oliver Rath]

Hi list,

what now worked:

- creating a cached data-lv
- creating a non-cached meta-lv
- converting data-lv to a thinpool-device with meta-lv as metadata

what not: doing the same thing with a cached meta-lv. Does this make sense?

Is the metadata already cached by lvm-logic? Do i have a cache thinpool
(with non-cached metadata) with the used way?

Tfh!
Oliver

Post by Oliver Rath
Hi list,
Im playing around with the new cache options. Ive created a lvm-device
on my cache-disk named lvx-cache (vg is dmivg). Additionally Ive created
a thinpool-device named winthinpool.
Now i wanted to use my cache-device to cache my thinpool-lvm, but this
~# lvconvert --type cache --cachepool dmivg/lvx_cache dmivg/winthinpool
Can't cache thin-pool volume dmivg/winthinpool.
isnt is possible to cache a thinpool-device?
Tfh!
Oliver
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https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

[Brassow Jonathan]

If it was me, I would put the thinMetaLV directly on the fast device (because it is small) and I would cache the thinDataLV.

Remember that some of what you are doing is pretty cutting edge. I wouldn't yet use caching + thin in production yet.

Also, consider making your thin devices redundant (if they are not already via backend storage).

brassow

Post by Oliver Rath
Hi list,
- creating a cached data-lv
- creating a non-cached meta-lv
- converting data-lv to a thinpool-device with meta-lv as metadata
what not: doing the same thing with a cached meta-lv. Does this make sense?
Is the metadata already cached by lvm-logic? Do i have a cache thinpool
(with non-cached metadata) with the used way?
Tfh!
Oliver

Post by Oliver Rath
Hi list,
Im playing around with the new cache options. Ive created a lvm-device
on my cache-disk named lvx-cache (vg is dmivg). Additionally Ive created
a thinpool-device named winthinpool.
Now i wanted to use my cache-device to cache my thinpool-lvm, but this
~# lvconvert --type cache --cachepool dmivg/lvx_cache dmivg/winthinpool
Can't cache thin-pool volume dmivg/winthinpool.
isnt is possible to cache a thinpool-device?
Tfh!
Oliver
_______________________________________________
linux-lvm mailing list
https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/

_______________________________________________
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https://www.redhat.com/mailman/listinfo/linux-lvm
read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/