Manuals / Seagate / Computer Equipment / Computer Drive

Seagate ST936701SS Hot plugging the drive, 4 S.M.A.R.T, Controlling S.M.A.R.T, Performance impact

Models: ST936701SS ST973401SS

1 86
Download 86 pages 16.24 Kb
Page 25
Image 25

5.2.3Hot plugging the drive

When a disc is powered on by switching the power or hot plugged, the drive runs a self test before attempting to communicate on its’ interfaces. When the self test completes successfully, the drive initiates a Link Reset starting with OOB. An attached device should respond to the link reset. If the link reset attempt fails, or any time the drive looses sync, the drive initiated link reset. The drive will initiate link reset once per second but alternates between port A and B. Therefore each port will attempt a link reset once per 2 seconds assuming both ports are out of sync..

If the self-test fails, the drive does not respond to link reset on the failing port.

Note. It is the responsibility of the systems integrator to assure that no temperature, energy, voltage haz- ard, or ESD potential hazard is presented during the hot connect/disconnect operation. Discharge the static electricity from the drive carrier prior to inserting it into the system.

Caution. The drive motor must come to a complete stop prior to changing the plane of operation. This time is required to insure data integrity.

5.2.4S.M.A.R.T.

S.M.A.R.T. is an acronym for Self-Monitoring Analysis and Reporting Technology. This technology is intended to recognize conditions that indicate imminent drive failure and is designed to provide sufficient warning of a failure to allow you to back up the data before an actual failure occurs.

Note. The drive’s firmware monitors specific attributes for degradation over time but can’t predict instanta- neous drive failures.

Each monitored attribute has been selected to monitor a specific set of failure conditions in the operating per- formance of the drive and the thresholds are optimized to minimize “false” and “failed” predictions.

Controlling S.M.A.R.T.

The operating mode of S.M.A.R.T. is controlled by the DEXCPT and PERF bits on the Informational Exceptions Control mode page (1Ch). Use the DEXCPT bit to enable or disable the S.M.A.R.T. feature. Setting the DEX- CPT bit disables all S.M.A.R.T. functions. When enabled, S.M.A.R.T. collects on-line data as the drive performs normal read and write operations. When the PERF bit is set, the drive is considered to be in “On-line Mode Only” and will not perform off-line functions.

You can measure off-line attributes and force the drive to save the data by using the Rezero Unit command. Forcing S.M.A.R.T. resets the timer so that the next scheduled interrupt is in two hours.

You can interrogate the drive through the host to determine the time remaining before the next scheduled mea- surement and data logging process occurs. To accomplish this, issue a Log Sense command to log page 0x3E. This allows you to control when S.M.A.R.T. interruptions occur. Forcing S.M.A.R.T. with the RTZ command resets the timer.

Performance impact

S.M.A.R.T. attribute data is saved to the disc so that the events that caused a predictive failure can be recre- ated. The drive measures and saves parameters once every two hours subject to an idle period on the drive interfaces. The process of measuring off-line attribute data and saving data to the disc is uninterruptable. The maximum on-line only processing delay is summarized below:

Maximum processing delay

 

 

On-line only delay

Fully-enabled delay

 

DEXCPT = 0, PERF = 1

DEXCPT = 0, PERF = 0

S.M.A.R.T. delay times

50 milliseconds

300 milliseconds

Savvio SAS Product Manual, Rev. D

19

Page 24 Page 26
Page 25
Image 25
Seagate ST936701SS manual Hot plugging the drive, 4 S.M.A.R.T, Controlling S.M.A.R.T, Performance impact, Milliseconds
Page 24 Page 26

ST936701SS, ST973401SS specifications

The Seagate ST936701SS and ST973401SS are high-performance enterprise hard drives designed for optimal data storage solutions in demanding environments. Both models belong to Seagate's Savvio series, which is renowned for its reliability and efficiency. These drives are tailored for critical applications such as database management, data warehousing, and online transaction processing.

The ST936701SS comes with a storage capacity of 36.4 GB, while the ST973401SS offers a larger capacity of 73.4 GB. This variance allows users to choose the drive that best suits their storage needs without compromising performance. Both drives utilize a 2.5-inch form factor, making them compact and suitable for high-density storage configurations.

A key feature of these drives is their impressive rotational speed of 10,000 RPM, which enhances data access times and improves overall system responsiveness. This speed allows for reduced latency and faster data transfer rates, critical for applications that require quick retrieval of large datasets.

In terms of technology, these drives utilize the Serial Attached SCSI (SAS) interface, which is favored in enterprise settings for its reliability and speed. SAS provides better performance than traditional SATA drives, particularly when dealing with high workloads, as it supports multiple concurrent connections and higher data throughput.

The ST936701SS and ST973401SS are also equipped with advanced features such as Seagate's Native Command Queuing (NCQ), which optimizes the order in which read and write commands are executed. This results in improved performance under multi-tasking conditions, essential for enterprise servers managing multiple requests simultaneously.

Additionally, both drives incorporate features aimed at enhancing data integrity and reliability. They support End-to-End Data Protection and are designed to endure the rigors of continuous operation, with MTBF (Mean Time Between Failures) ratings that bolster their reputation for durability.

Energy efficiency is another notable characteristic, as both drives are designed to reduce power consumption without sacrificing performance. This is particularly important in enterprise environments where power management contributes to lower operational costs.

In conclusion, the Seagate ST936701SS and ST973401SS drives are robust, reliable storage solutions tailored for enterprise applications. With their high performance, advanced technology features, and capacity options, they provide organizations with the scalability and efficiency required in today’s data-driven landscape. Whether it's for critical data management tasks or high-access applications, these drives stand out as a solid choice for any enterprise storage strategy.