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Seagate ST300MM0026 Savvio 10K.1 FC Product Manual - Page 21

Fibre Channel Interface Product Manual

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decides that a prefetch hit will not likely occur. If the host is not using software interleave, and if two sequential read operations are not for contiguous blocks of data, ARLA disables prefetch, but as long as sequential read operations request contiguous blocks of data, ARLA keeps prefetch enabled. 4.5.3 Optimizing cache performance for desktop and server applications Desktop and server applications require different drive caching operations for optimal performance. This means it is difficult to provide a single configuration that meets both of these needs. In a desktop environment, you want to configure the cache to respond quickly to repetitive accesses of multiple small segments of data without taking the time to "look ahead" to the next contiguous segments of data. In a server environment, you want to configure the cache to provide large volumes of sequential data in a non-repetitive manner. In this case, the ability of the cache to "look ahead" to the next contiguous segments of sequential data is a good thing. The Performance Mode (PM) bit controls the way the drive switches the cache buffer into different modes of segmentation. In "server mode" (PM bit = 0), the drive can dynamically change the number of cache buffer segments as needed to optimize the performance, based on the command stream from the host. In "desktop mode" (PM bit = 1), the number of segments is maintained at the value defined in Mode Page 8, Byte 13, at all times. For additional information about the PM bit, refer to the Unit Attention Parameters page (00h) of the Mode Sense command (1Ah) in the Fibre Channel Interface Product Manual, part number 77767496. Savvio FC Product Manual, Rev. D 15

Section	Page
1.0 Scope	7
2.0 Applicable standards and reference documentation	9
2.1 Standards	9
2.1.1 Electromagnetic compatibility	9
2.1.1.1 Electromagnetic susceptibility	9
2.1.2 Electromagnetic compliance	10
2.2 Reference documents	11
3.0 General description	13
3.1 Standard features	13
3.2 Media description	14
3.3 Performance	14
3.4 Reliability	15
3.5 Formatted capacities	15
3.5.1 Programmable drive capacity	15
3.6 Factory-installed accessories	16
3.7 Factory-installed options	16
3.8 User-installed accessories	16
4.0 Performance characteristics	17
4.1 Internal drive characteristics	17
4.2 Seek performance characteristics	17
4.2.1 Access time	17
4.2.2 Format command execution time for ³ 512-byte sectors (minutes)	18
4.2.3 General performance characteristics	18
4.3 Start/stop time	18
4.4 Prefetch/multi-segmented cache control	19
4.5 Cache operation	19
4.5.1 Caching write data	20
4.5.2 Prefetch operation	20
4.5.3 Optimizing cache performance for desktop and server applications	21
5.0 Reliability specifications	23
5.1 Error rates	23
5.1.1 Recoverable Errors	23
5.1.2 Unrecoverable Errors	23
5.1.3 Seek errors	24
5.1.4 Interface errors	24
5.2 Reliability and service	24
5.2.1 Mean time between failures (MTBF)	24
5.2.2 Preventive maintenance	24
5.2.3 Hot plugging the drive	24
5.2.4 S.M.A.R.T.	25
5.2.5 Thermal monitor	26
5.2.6 Drive Self Test (DST)	27
5.2.6.1 DST failure definition	27
5.2.6.2 Implementation	28
5.2.6.2.1 State of the drive prior to testing	28
5.2.6.2.2 Invoking DST	28
5.2.6.2.3 Short and extended tests	28
5.2.6.2.4 Log page entries	29
5.2.6.2.5 Abort	29
5.2.7 Product warranty	29
6.0 Physical/electrical specifications	31
6.1 AC power requirements	31
6.2 DC power requirements	31
6.2.1 Conducted noise immunity	33
6.2.2 Power sequencing	33
6.2.3 Current profiles	33
6.3 Power dissipation	36
6.4 Environmental limits	38
6.4.1 Temperature	38
6.4.2 Relative humidity	38
6.4.3 Effective altitude (sea level)	38
6.4.4 Shock and vibration	39
6.4.4.1 Shock	39
6.4.4.2 Vibration	41
6.4.5 Air cleanliness	41
6.4.6 Corrosive environment	41
6.4.7 Acoustics	42
6.4.8 Electromagnetic susceptibility	42
6.5 Mechanical specifications	43
7.0 Defect and error management	45
7.1 Drive internal defects/errors	45
7.2 Drive error recovery procedures	45
7.3 FC-AL system errors	46
8.0 Installation	47
8.1 Drive orientation	47
8.2 Cooling	47
8.3 Drive mounting	48
8.4 Grounding	48
9.0 Interface requirements	49
9.1 FC-AL features	49
9.1.1 Fibre Channel link service frames	49
9.1.2 Fibre Channel task management functions	50
9.1.3 Fibre Channel task management responses	50
9.1.4 Fibre Channel port login	51
9.1.5 Fibre Channel port login accept	52
9.1.6 Fibre Channel Process Login	52
9.1.7 Fibre Channel Process Login Accept	53
9.1.8 Fibre Channel fabric login	53
9.1.9 Fibre Channel fabric accept login	54
9.1.10 Fibre Channel Arbitrated Loop options	55
9.2 Dual port support	55
9.3 SCSI commands supported	56
9.3.1 Inquiry data	61
9.3.2 Mode Sense data	61
9.4 Miscellaneous operating features and conditions	65
9.5 FC-AL physical interface	66
9.5.1 Physical characteristics	66
9.5.1.1 Physical description	66
9.5.2 Connector requirements	67
9.5.3 Electrical description	67
9.5.4 Pin descriptions	68
9.5.5 FC-AL transmitters and receivers	69
9.5.6 Power	69
9.5.7 Fault LED Out	69
9.5.8 Active LED Out	70
9.5.9 Enable port bypass signals	70
9.5.10 Motor start controls	70
9.5.11 SEL_6 through SEL_0 ID lines	71
9.5.11.1 Parallel Enclosure Services Interface (ESI)	71
9.5.12 Device control codes	73
9.6 Signal characteristics	73
9.6.1 TTL input characteristics	73
9.6.2 Differential PECL output	74
9.6.3 Differential PECL input	74

Match case Limit results 1 per page

Savvio FC Product Manual, Rev. D

decides that a prefetch hit will not likely occur. If the host is not using software interleave, and if two sequential

read operations are not for contiguous blocks of data, ARLA disables prefetch, but as long as sequential read

operations request contiguous blocks of data, ARLA keeps prefetch enabled.

4.5.3

Optimizing cache performance for desktop and server applications

Desktop and server applications require different drive caching operations for optimal performance. This

means it is difficult to provide a single configuration that meets both of these needs. In a desktop environment,

you want to configure the cache to respond quickly to repetitive accesses of multiple small segments of data

without taking the time to “look ahead” to the next contiguous segments of data. In a server environment, you

want to configure the cache to provide large volumes of sequential data in a non-repetitive manner. In this

case, the ability of the cache to “look ahead” to the next contiguous segments of sequential data is a good

thing.

The Performance Mode (PM) bit controls the way the drive switches the cache buffer into different modes of

segmentation. In “server mode” (PM bit = 0), the drive can dynamically change the number of cache buffer

segments as needed to optimize the performance, based on the command stream from the host. In “desktop

mode” (PM bit = 1), the number of segments is maintained at the value defined in Mode Page 8, Byte 13, at all

times. For additional information about the PM bit, refer to the Unit Attention Parameters page (00h) of the

Mode Sense command (1Ah) in the

Fibre Channel Interface Product Manual

, part number 77767496.