7.4Background Media Scan

Background Media Scan (BGMS) is a self-initiated media scan. It performs sequential reads across the entire pack of the media while the drive is idle. In RAID arrays, BGMS allows hot spare drives to be scanned for defects prior to being put into service by the host system. On regualr duty drives, if the host system makes use of the BGMS Log Page, it can avoid placing data in suspect locations on the media. Unrecovered error sites found during BGMS will be logged and recovered error sites will be logged or reallocated per ARRE/AWRE settings.

With BGMS, the host system can consume less power and system overhead by only checking BGMS status/ results rather than tying up the bus and consuming power in the process of host-initiated media scanning activ- ity.

Since the background scan functions are only done during idle periods, BGMS causes a negligible impact to system performance. Background media scan will begin after 500ms of idle time. Other features that normally use idle time to function will function normally because BGMS functions for bursts of 800ms and then sus- pends activity to allow other background functions to operate. Additionally, BGMS operates in segments of 400 block reads, checking for host commands upon completion of each of the block segments.

The BGMS function will complete any BGMS-initiated error recovery prior to returning to service host-initiated commands. Overhead associated with a return to host-servicing activity from BGMS only impacts the first com- mand that interrupted BGMS. This results in a typical delay of about 4 ms.

7.4.1Media Pre-Scan

Media Pre-Scan is an optional feature that allows the drive to handle unrecovered media errors that would oth- erwise have been found by the host system during critical data accesses early in the integration process at customer sites. This should reduce integration DPPM (defective parts per million) by identifying and repairing media errors that arose during shipping and handling. Media Pre-Scan replaces all host-initiated Write com- mands with Write-Verify commands when the drive is accessing areas of the media yet untouched by BGMS- initiated scanning activity.

The drive will attempt to run BGMS on the entire pack of the drive. This will result in increasingly large portion so fthe drive having been accesed, provided there is adequate idle time to allow BGMS to run. During the Pre- Scan period, all Write commands that are in un-BGMS-scanned areas are converted to Write-Verify com- mands. To expedite the scan of the full pack and the subsequenty exit from the Pre-Scan period, BGMS will begin immediately when the drive goes to idle during the Pre-Scan period, as opposed to waiting 500ms as is done under non-Pre-Scan conditions.

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Seagate ST3146707LW/LC, ST3300007LW/LC, ST373207LW/LC manual Background Media Scan, Media Pre-Scan
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ST3300007LW/LC, ST373207LW/LC, ST3146707LW/LC specifications

Seagate's ST3146707LW/LC, ST373207LW/LC, and ST3300007LW/LC are part of the company's renowned line of hard disk drives (HDDs), specifically designed for enterprise and high-performance computing environments. With their reliability and performance, these drives have become popular choices for data centers and critical applications requiring extensive storage capabilities.

One of the standout features of these models is their capacity to handle large volumes of data. The ST3146707LW/LC has a capacity of 146GB, while the ST373207LW/LC offers 73GB, and the ST3300007LW/LC comes with a substantial 300GB. These capacities make them well-suited for applications that require not only high storage space but also rapid access to data.

In terms of performance, these drives utilize a 10,000 RPM spindle speed, which significantly enhances data access times and overall performance. The combination of fast rotational speeds with Seagate's advanced caching algorithms allows for swift data retrieval, making these drives ideal for environments where speed is crucial.

These HDDs also employ the SCSI (Small Computer System Interface) interface, which promises high data transfer rates and reliability in enterprise-level applications. The Ultra320 SCSI interface can support transfer rates up to 320 MB/s, ensuring that the drives can efficiently communicate with other system components.

Another key technology featured in these models is Seagate's Adaptive Error Correction technology, which enhances data integrity and reliability. This feature helps in the detection and correction of errors that can occur during data transfer, reducing the risk of data loss.

Performance consistency is critical in enterprise environments, and these drives are built to endure the demands of 24/7 operation. They are designed with robust mechanisms to withstand temperature fluctuations, shock, and vibrations commonly found in data center settings.

In summary, the Seagate ST3146707LW/LC, ST373207LW/LC, and ST3300007LW/LC hard drives exemplify advanced features and technologies tailored for enterprise storage solutions. With significant capacities, impressive spindle speeds, SCSI connectivity, and reliability-focused technologies, these drives remain a valuable asset for businesses relying on stable and high-performance data storage.
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