Best strategy for caching VMs storage

Santiago Castillo Oli
2021-05-21T12:06:33Z

Hi there.

I have a host running 4 VMs using qcow2 storage on a ext4 fs over HDD.
Each VM has 3 qcow files (system, data and swap). I know I have an I/O
bottleneck.

I want to use bcache with an SSD to accelerate disk access but I´m not
sure where should I put bcache on storage stack.

Should I use bcache on host or in guests?

Just one bcache backing device for a single (ext4) filesystem with all
qcow files there, or different bcache and backing devices for each qcow2
file?

Right know, I prefer qcow2 over thin-lvm for storage, but i could change
my mind if thin-lvm is a much better combination for bcache.

What would be the best strategy for caching VMs storage ?

Any recommendation, please?

Regards and thank you

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