[LSF/MM/BPF TOPIC] Improving Block Layer Tracepoints for Next-Generation Backup Systems

[Song Liu]

On Sat, Jan 4, 2025 at 9:52 AM Vishnu ks <ksvishnu56 at gmail.com> wrote:
>
[...]
>
> @Song: Our approach fundamentally differs from md/raid in several ways:
>
> 1. Network-based vs Local:
>    - Our system operates over network, allowing replication across
> geographically distributed systems
>    - md/raid works only with locally attached storage devices

md-cluster (https://docs.kernel.org/driver-api/md/md-cluster.html)
does support RAID in a cluster.

>
> 2. Replication Model:
>    - We use asynchronous replication with configurable RPO windows
>    - md/raid requires synchronous, immediate mirroring of data

immediate mirroring is probably more efficient, as the system doesn't
need to read the data from the device.

> 3. Recovery Capabilities:
>    - We provide point-in-time recovery through incremental sector tracking
>    - md/raid focuses on immediate redundancy without historical state

IIUC, the idea is to build a block level remote full journal. By "full" journal,
I mean the journal contains all the actual data in addition to metadata.
I think the consistency can be really tricky with write cache etc.

Thanks,
Song