[linux-lvm] LVM cache/dm-cache questions.

[Sergei Franco]

Thank you!

That clears up a few questions!


Regards.

Sergei.

On 21 June 2016 at 04:27, Brassow Jonathan <jbrassow at redhat.com> wrote:
>
>> On Jun 11, 2016, at 7:36 PM, sergei <sergei.franco at gmail.com> wrote:
>>
>> Hi,
>>
>> I have a few simple questions regarding relatively new feature LVM cache/dm-cache.
>>
>> From second hand information on internet, it appears that you cannot resize cached volume.
>> Please correct me if I am wrong: to resize a cached volume, one needs to lvremove the cache, resize and recreate the cache?
>
> This is true at the moment.  You are likely to be able to simply resize online in the future.
>
>> In scenario where cache device fails, how safe is the data on the cached LVM?
>
> If you are using writethrough, quite safe.  If you are using ‘writeback’, probably not (RAID for your cache in this case would probably be wise).
>
>> Is it possible to make snapshots of the cached device?
>
> easy answer is “no”.
>
> complicated answer includes a ‘yes’.  You can cache a poolDataLV, then your thinLV and all its thinSnaps would be cached.
>
>  brassow
>
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