Closed jvinolas closed 4 months ago
How much memory does your server have?
64 GB, only 22GB used till the hung that peaks instantly to consume the whole ram.
UPDATE: I've implemented open-cas with the same system and worked, so I assume it should work with writeboost also.
According to wiki, writeboost consumes roughly 1% of the cache device size for the in-memory metadata. In your case, the cache device is 4TB so the system consumes 40GB RAM. I think this is the cause of your problem.
We tried to build db-writeboost cache on top of vdo (https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html/deduplicating_and_compressing_logical_volumes_on_rhel/introduction-to-vdo-on-lvm_deduplicating-and-compressing-logical-volumes-on-rhel) deduplication.
When creating the writeboost cache, after few minutes, the RAM on the server, that was being used at a constant 36%, peak to 100% instantly, triggering the OOM.
The creation was:
The devices are setup as following:
Backing Device: VDO over a raid
Caching device: raid
And the writeboost packages are the Ubuntu Jammy repository one's:
Is this scenario expected to work?