Questions tagged [scsi]

Small Computer System Interface (SCSI, pronounced skuz-ee) is a set of parallel interface standards developed by the American National Standards Institute (ANSI) for physically connecting and transferring data between computers and peripheral devices(like printers, disk drives, scanners and other). It is a fast bus and supported by all major operating systems.

Small Computer System Interface (SCSI, pronounced skuz-ee) is a set of standards for physically connecting and transferring data between computers and peripheral devices. The official name of the SCSI standard is: ANSI X3.131.

The SCSI standards define commands, protocols, and electrical and optical interfaces. SCSI uses a low-voltage differential (LVD) bus, a method where data is transmitted by comparing the difference in voltage between a pair of wires. SCSI is most commonly used for hard disks and tape drives, but it can connect a wide range of other devices, including scanners and CD drives.

Some important features:

  • SCSI is capable of supporting eight devices, or sixteen devices with Wide SCSI.
  • The latest version, 16-bit Ultra-640 (Fast-320) SCSI has a 640 MBps transfer speed.
  • SCSI standards are generally backward-compatible.

Common SCSI components:

  • Initiator - it issues requests for service by the SCSI device and receives responses.
  • Target - A SCSI target is typically a physical storage device like a hard-disk or a storage array
  • Service delivery subsystem - it allows communication to occur between the initiator and the target

The SCSI subsystem has a 3 level architecture with the "upper" level being closest to the user/kernel interface while the "lower" level is closest to the hardware.

For more info: http://en.wikipedia.org/wiki/SCSI

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Writing into Each LBA on Disk

There is a need to write into each LBA on the disk using SCSI CDB. Here i have constructed a while/for loop for writing into each LBA. I am using 10 byte CDB . How do i represent 32 bit LBA so that it iterates from LBA 0 to Maximun LBA . What…
arun
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Re-scan LUN on Linux

We have expend existing LUN size on EMC Storage and now i want to re-scan on Host side but i don't know how to figure out SCSI ID of that specific LUN. I am new to storage.. This is what i am doing but don't know whether it is a right way or not…
Satish
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Using WRITE SECTOR(S) EXT ATA command with SCSI ATA PASS-THROUGH(16)

Welcome. I have a problem while executing SCSI command ATA PASS-THROUGH(16) for WRITE SECTOR(S) EXT - 34h, PIO Data-Out (for WRITE DMA EXT - 35h, DMA identical result). I use kernel 2.6.39. I have one HDD(SATA) that is controlled by SCSI. I want to…
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How to get serial number for Hard Drive

How to get the unique number (serial number/ID) for Processor (CPU), SCSI, Display, and IDE using C++ program other than WMI and asm code?
shankara
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ATA commands to USB drive

Windows 7 C Programming Visual C++ 2008 (in a VMWare) I'd like to send some ATA commands (IDENTIFY DEVICE, READ NATIVE MAX ADDRESS, SET MAX ADDRESS) with DeviceIOControl to a USB hard drive. Therefore I have some questions. As I understood, USBSTOR…
toetoe
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SPTI "Mode Select" unexpectedly fails in Win 7 64-bit

I'm in the middle of converting some older code to talk with a custom SCSI device. The original code was written for WinXP and ASPI, and the newer code needs to work on Win7 and SPTI. My problem is that the newer code fails on a call to do a SCSI…
Bob Murphy
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Strange error with every GUI program in Eclipse

Unable to open SCSI controller 0:[\] , error code: 0x5 Unable to open SCSI controller 1:[\] , error code: 0x5 In almost every program I write with a GUI, these two errors appear when the program is done executing. It just randomly started and I…
tckmn
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Handle system shutdown in virtual disk driver

I'm developing a virtual disk driver for Windows that is using an ordinary file as a storage (much like VHD virtual disk driver that comes with Windows 7). My virtual driver supports writing and has a cache that I need to flush when OS shuts down.…
Isso
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What does SCSI LUN id mean and what is its use?

In Linux what does the LUN id mean in ioctl SCSI_IOCTL_GET_LUNID? And what does the signify? How will it help?
arun_vj
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Looking for where in the linux 2.6.33.20 kernel source SCSI timeouts are created/set up

In older versions of the kernel (2.6.25.8), it was in drivers/scsi/scsi_error.c in the functions scsi_add_timer and scsi_delete_timer: http://www.cs.fsu.edu/~baker/devices/lxr/http/source/linux/drivers/scsi/scsi_error.c?v=2.6.25.8 I can't seem to…
Jdban101
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How to read bytes from a device using c/c++ in windows

So here's the background: I've got this SCSI device with media that has raw data on it (for simplicity let's say it contains abc123). This device is on a Windows machine. I'd like to use C/C++ to initalize the device, open it, send the SCSI read…
redhotspike
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Getting a compile error with ntddscsi.h

I am having a bit of trouble with the following include: #include When I compile (using NetBean 7.1 & Cygwin C++ compiler), I am told that I need to define "SCSI_PASS_THROUGH" before I can use it... in ntddscsi.h however, it is…
redhotspike
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SCSI commands that can benefit from a full duplex SAS connection

One of the distinguishing features of SAS is a full-duplex connection between the HBA and device. SATA provides only half-duplex connections. I used to think that SAS drives could simultaneously ingest and retrieve data using both directions of a…
Vitaly Isaev
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How to send a generic SCSI command to a USB drive under MACOS

This has been asked a few times, but I haven't found any actual resolution to how to accomplish this. I will admit, I am a Linux programmer, not MACOS, so this is a very different world, but this shouldn't be so difficult. I am attempting to send a…
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ISCSI Becomes Much More Slower After An Intermediate Layer

I'm new to iSCSI protocol and I have a task to catch and interpret the commands between QEMU and iSCSI server when a VM is boot from iSCSI drive. I setup tgtd on Ubuntu and managed to install a guest OS into a disk image created by qemu-img with a…
citrate
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