我知道,在旧的 ATA 标准中存在这样的可能性:“READ LONG”命令产生 LBA 扇区 + ECC 有效负载。sg_read_long
在 Linux 中支持,但是该命令已经过时很长一段时间了,所以我的 HDD 没有实现它并不让我感到惊讶。
root@ubuntu:~# sg_read_long --lba=2118229 /dev/sdc
sg_read_long: issue read long (10) to device /dev/sdc
xfer_len=520 (0x208), lba=2118229 (0x205255), correct=0
SCSI READ LONG (10) command not supported
root@ubuntu:~# sg_read_long -v --16 --lba=2118229 /dev/sdc
sg_read_long: issue read long (16) to device /dev/sdc
xfer_len=520 (0x208), lba=2118229 (0x205255), correct=0
Read Long (16) cmd: 9e 11 00 00 00 00 00 20 52 55 00 00 02 08 00 00
read long (16): Fixed format, current; Sense key: Illegal Request
Additional sense: Invalid field in cdb
SCSI READ LONG (16) command, bad field in cdb
以下hdparm
也是转储:
root@ubuntu:~# hdparm -I /dev/sdc
/dev/sdc:
ATA device, with non-removable media
Model Number: WDC WD30EZRX-00MMMB0
Serial Number: WD-WCAWZ1777146
Firmware Revision: 80.00A80
Transport: Serial, SATA 1.0a, SATA II Extensions, SATA Rev 2.5, SATA Rev 2.6, SATA Rev 3.0
Standards:
Supported: 8 7 6 5
Likely used: 8
Configuration:
Logical max current
cylinders 16383 16383
heads 16 16
sectors/track 63 63
--
CHS current addressable sectors: 16514064
LBA user addressable sectors: 268435455
LBA48 user addressable sectors: 5860533168
Logical Sector size: 512 bytes
Physical Sector size: 4096 bytes
Logical Sector-0 offset: 0 bytes
device size with M = 1024*1024: 2861588 MBytes
device size with M = 1000*1000: 3000592 MBytes (3000 GB)
cache/buffer size = unknown
Capabilities:
LBA, IORDY(can be disabled)
Queue depth: 32
Standby timer values: spec'd by Standard, with device specific minimum
R/W multiple sector transfer: Max = 16 Current = 0
DMA: mdma0 mdma1 mdma2 udma0 udma1 udma2 udma3 udma4 udma5 *udma6
Cycle time: min=120ns recommended=120ns
PIO: pio0 pio1 pio2 pio3 pio4
Cycle time: no flow control=120ns IORDY flow control=120ns
Commands/features:
Enabled Supported:
* SMART feature set
Security Mode feature set
* Power Management feature set
* Write cache
* Look-ahead
* Host Protected Area feature set
* WRITE_BUFFER command
* READ_BUFFER command
* NOP cmd
* DOWNLOAD_MICROCODE
Power-Up In Standby feature set
* SET_FEATURES required to spinup after power up
SET_MAX security extension
* 48-bit Address feature set
* Device Configuration Overlay feature set
* Mandatory FLUSH_CACHE
* FLUSH_CACHE_EXT
* SMART error logging
* SMART self-test
* General Purpose Logging feature set
* 64-bit World wide name
* {READ,WRITE}_DMA_EXT_GPL commands
* Segmented DOWNLOAD_MICROCODE
* Gen1 signaling speed (1.5Gb/s)
* Gen2 signaling speed (3.0Gb/s)
* Gen3 signaling speed (6.0Gb/s)
* Native Command Queueing (NCQ)
* Host-initiated interface power management
* Phy event counters
* NCQ priority information
DMA Setup Auto-Activate optimization
* Software settings preservation
* SMART Command Transport (SCT) feature set
* SCT LBA Segment Access (AC2)
* SCT Features Control (AC4)
* SCT Data Tables (AC5)
unknown 206[12] (vendor specific)
unknown 206[13] (vendor specific)
Security:
Master password revision code = 65534
supported
not enabled
not locked
not frozen
not expired: security count
supported: enhanced erase
508min for SECURITY ERASE UNIT. 508min for ENHANCED SECURITY ERASE UNIT.
Logical Unit WWN Device Identifier: 50014ee25bc950c2
NAA : 5
IEEE OUI : 0014ee
Unique ID : 25bc950c2
Checksum: correct
我想读取几个没有 ECC 的扇区来更好地转储半死硬盘。
故事的另一部分是 ATAPI-8 命令集。它声明SCT 读/写 长何时起作用的命令当 IDENITFY DEVICE 数据字 106 位 12 被清除为零时根据T13/1699-D Revision 6a, Working Draft AT Attachment 8 - ATA/ATAPI Command Set (ATA8-ACS)
。当且仅当设备逻辑扇区长度超过 256 个字。
另一方面,它只适用于 512 字节扇区,所以我不明白当 ECC/CRC 应用于 4k 扇区时它是否有效。
答案1
简短的回答:不。
SCT 读/写 长已被淘汰T13/e08153r1
ACS-2 过时的 SCT 读写长.
T13/2015-D Revision 4, Working Draft ATA/ATAPI Command Set - 2 (ACS-2)
日期为 2010 年 12 月 7 日 已将此命令标记为过时。
各州T13/e08153r1
的理由是删除读/写长整型命令:
记录技术的最新变化使得主机能够将其自己的错误校正/检测数据强制传输到设备的想法变得毫无意义。
看http://www.t13.org/documents/UploadedDocuments/docs2009/e08153r1-Obsolete_SCT_Read_Long_and_SCT_Write_Long.pdf 和 http://www.scribd.com/doc/88224835/Ataatapi-Command-Set-2-Acs-2-Rev4详细信息。
故事结局。
PSSCT LBA Segment Access (AC2)
应该确实SCT Write Same (AC2)
在 hdparm dump 中:)