Hi Dan, I think the the block level event log is more like log only system. When en event happens, it is not necessary to take immediate action. (I guess this is different to bad block list?). I would hope the event log to track more information. Some of these individual event may not be very interesting, for example, soft error or latency outliers. However, when we gather event log for a fleet of devices, these "soft event" may become valuable for health monitoring. Thanks, Song > On Jan 20, 2017, at 9:46 PM, Dan Williams <dan.j.williams@xxxxxxxxx> wrote: > > On Wed, Jan 18, 2017 at 3:34 PM, Song Liu <songliubraving@xxxxxx> wrote: >> >> Media health monitoring is very important for large scale distributed storage systems. >> Traditionally, enterprise storage controllers maintain event logs for attached storage >> devices. However, these controller managed logs do not scale well for large scale >> distributed systems. >> >> While designing a more flexible and scalable event logging systems, we think it is better >> to build the log in block layer. Block level event logging covers all major storage media >> (SCSI, SATA, NVMe), and thus minimizes redundant work for different protocols. >> >> In this LSF/MM, we would like to discuss the following topics with the community: >> 1. Mechanism for drivers report events (or errors) to block layer. >> Basically, we will need a traceable function for the drivers to report errors >> (most likely right before calling end_request or bio_endio). >> >> 2. What mechanism (ftrace, BPF, etc.) is mostly preferred for the event logging? >> >> 3. How should we categorize different events? >> Currently, there are existing code that translates ATA error (ata_to_sense_error) >> and NVMe error (nvme_trans_status_code) to SCSI sense code. So we can >> leverage SCSI Key Code Qualifier for event categorizations. >> >> 4. Detailed discussions on data structure for event logging. >> >> We will be able to show a prototype implementation during LSF/MM. > > Hi Song, > > How is this distinct from tracking a badblocks list? > > I'm interested in this topic since we have both media error reporting > / scrubbing for nvdimms as well "SMART" media health retrieval > commands. -- To unsubscribe from this list: send the line "unsubscribe linux-block" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
