KIOXIA Enterprise and Data Center drives are architected with full end-to-end data path protection so you can be sure that your data will be protected from being transferred with errors. But did you know there is an extra level of protection that can be enabled in KIOXIA enterprise drives to extend that data path protection boundary out to the HBA, controller, or driver level?
The T10 Technical Committee is a longstanding active standards body responsible for SCSI and SAS related specifications. From this standards body, an enterprise feature called Protection Information (PI) has been ported over to NVMe ® specification and deployed in NVMe™ SSDs.
T10 Protection Information is a feature first enabled on enterprise SAS HDDs and SSDs that has been included in the NVMe specification, and has been included in KIOXIA Enterprise class NVMe SSDs since CM5. T10 Protection Information allows for additional metadata to reside with user data which contains additional fields to help protect against cases of misdirected writes and silent data corruption, to name a few scenarios.
T10 Protection Information is supported by popular HBA and storage controller vendors, as well as some newer Linux® operating systems. With T10 PI enabled, as a piece of data traverses the data path, from the OS or HBA/controller to SSD media (NAND Flash) and back, the Protection Information metadata is checked by both the drive and host device. This ensures an extra layer of data integrity protection for your data.
KIOXIA Enterprise class NVMe SSDs are already rated for a robust 10E-17 uncorrectable bit error rate (UBER), and have data protection features such as Power Loss Protection, and die failure recovery. With T10 PI, not only does this add another layer of data protection within the drive, but provides checks against issues with host controllers or data path transport problems.
How Does T10 PI Work?
KIOXIA Enterprise SSDs support T10 PI through extended LBA formats. Traditional drive block sizes are 512 bytes and 4096 bytes. T10 DIF adds an additional 8 bytes of metadata for 520 bytes or 4104 bytes of data per logical block address. The additional 8 bytes of data included with the user data contains 3 main segments; a 16 bit guard tag, a 16 bit application tag, and a 32 bit reference tag.
The guard tag is simply 16 bits of cyclic redundancy check (CRC) protection generated by the host system during a write operation and provides a validation checkpoint of the user data.
The reference tag contains either part of the LBA of an individual sector, or part of the LBA in the original command. This is most helpful in detecting misdirected writes.
The application tag is an open-ended field that is definable by individual vendors or use cases for their own metadata purposes.
How to enable T10 Protection Information on KIOXIA drives
T10 Protection Information is only available on KIOXIA Enterprise class drives, for NVMe SSDs the CM series and FL series, and for SAS the PM series SSDs. For NVMe SSDs, T10 Protection Information can be enabled for each namespace created on a drive through specific format parameters. Using tools provided by your storage appliance provider or by using standard NVMe tools such as nvme-cli.
Protection Information Location (PIL): for T10 PI, set this value to 0b to indicate the metadata location is provided after user data.
Protection Information (PI): This is used to set the type of Protection Information enabled. Available settings are Disabled, Type 1, Type 2, and Type 3. KIOXIA CM7 supports all settings. Disabled means there is no Protection Information checking. Each type defines what fields are checked as part of data transfer, and what their expected contents should be. Refer to the NVMe specification for further definitions and details.
Metadata Settings (MSET): This is used to specify where the metadata resides. Select 1b to indicate metadata is transferred as part of an extended LBA, required for T10 PI.
KIOXIA Enterprise SSDs + T10 PI: A Winning Combination
T10 Protection Information provides an extra layer of protection for user data and comes as a standard feature with KIOXIA Enterprise SSDs such as FL6, CM7, and PM7. Simply ensure support from a host system and format KIOXIA Enterprise drives accordingly. With industry standard UBER ratings and additional data protection features, KIOXIA Enterprise drives with PI enabled can provide the peace of mind that data will be secure during transport and ready to service application needs.
Notes
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