On Wed, 2017-01-18 at 23:34 +0000, Song Liu wrote:

Media health monitoring is very important for large scale distributed sto=

rage systems.=20

Traditionally, enterprise storage controllers maintain event logs for att=

ached storage

devices. However, these controller managed logs do not scale well for lar=

ge scale=20

distributed systems.=20
=20
While designing a more flexible and scalable event logging systems, we th=

ink it is better

to build the log in block layer. Block level event logging covers all maj=

or storage media

(SCSI, SATA, NVMe), and thus minimizes redundant work for different proto=

cols.=20

=20
In this LSF/MM, we would like to discuss the following topics with the co=

mmunity:

    1. Mechanism for drivers report events (or errors) to block layer.=20
       Basically, we will need a traceable function for the drivers to re=

port errors=20

       (most likely right before calling end_request or bio_endio). =20
 =20
    2. What mechanism (ftrace, BPF, etc.) is mostly preferred for the eve=

nt logging?

=20
    3. How should we categorize different events?
       Currently, there are existing code that translates ATA error (ata_=

to_sense_error)=20

       and NVMe error (nvme_trans_status_code) to SCSI sense code. So we =

can=20

       leverage SCSI Key Code Qualifier for event categorizations.=20
=20
    4. Detailed discussions on data structure for event logging.=20
=20
We will be able to show a prototype implementation during LSF/MM.=20

I'd like to participate in this discussion.

Bart.=