write() issue during a low level hdd access Post: 302397635

Sponsored Content

Top Forums Programming write() issue during a low level hdd access Post 302397635 by sponnusa on Monday 22nd of February 2010 09:02:19 PM

02-22-2010

Registered User

Wow! It's all I can say!

That was a fantastic reply straight to temple! Smilie

Yup! I read about the Libata stuff implementation and got to know that I cannot implement it in a program as you have pointed out!

You are right. Just that my requirement is to have a raw I/O with the drive, and I don't see a point in kernel to have it as it will not be used by anybody.

And well said about the windows programmers. rofl!! Smilie

(seriously no offense windows programmers!) (me neither! Smilie

)

hdparm only works for IDE/SATA drives and on certain systems, it fails to send commands to the HDD. If the drive is in really bad state, i.e., SMART failure is detected and / or if the BIOS restricts certain features based on SMART values (On certain IBM / HP / DELL Systems), hdparm is unable to send commands. And sdparm does not have certain key options for scsi drives as well (such as setting / clearing low level parameters).

Also, according to the ata specifications, timeout would be only for certain operations and ranges in the order of nanaseconds (400ns is default i believe).
And might not work in this case as it has to pass through the kernel / driver layers.

In one of the earlier posts, you pointed out about the option of having a driver for talking to the drives. Is there any generic direction / pointers you can point to or I should start at libata / scsi drivers?

I am extremely grateful for all the help / advice.

sponnusa

View Public Profile for sponnusa

Find all posts by sponnusa

7 More Discussions You Might Find Interesting

1. UNIX for Dummies Questions & Answers

Low level format?

I want to do a low level format like in windows (C:\format c:) but I don't know how it works in unix or linux.. Can somebody help me ? thnx :)

2. HP-UX

Access to a second HDD

Hello How to access to a second hard disk on a HP-UX system? Thanks

3. IP Networking

Best reference for understanding low level info on nic cards drivers and functionality

Hi, What is the best reference that gives in detail on nic cards configuration , assigning multiple ip addresses to a single interface, netlink library etc and all basic stuff at this level..? Thanks

4. AIX

High Runqueue (R) LOW CPU LOW I/O Low Network Low memory usage

Hello All I have a system running AIX 61 shared uncapped partition (with 11 physical processors, 24 Virtual 72GB of Memory) . The output from NMON, vmstat show a high run queue (60+) for continous periods of time intervals, but NO paging, relatively low I/o (6000) , CPU % is 40, Low network....

5. Programming

System calls and C language low-level qualities???

Hi friends, I hope everyone is fine and doing well. I queried in my previous thread about the low-level qualities of C/C++ languages.I really thank you people for explaining, it was really helpful. One more ambiquity that I have in my mind is regarding the unix system calls like open, creat,...

6. Programming

Why is C/C++ considered low-level languages???

Hi friends, I hope everyone is doing well and fine. I have always been hearing that C/C++ are relatively low-level as compared to Java/C# etc. Could you please tell me some low-level qualities of C/C++? And I think disk deframenters are written in C/C++, please correct me if I am wrong. And please...

7. Programming

Low level X11 programming

How to use X11 without Xlib not XCB? How draw window directly on low level? I must use anyway window manager like Motif? I have ridden that X11 has server-client architecture, client send via TCP/IP to port 6000 request for primitives and get replies. Where is detailed description of it? In X11...

LEARN ABOUT DEBIAN

tapeinfo

TAPEINFO(1)						      General Commands Manual						       TAPEINFO(1)

NAME

       tapeinfo - report SCSI tape device info

SYNOPSIS

       tapeinfo -f <scsi-generic-device>

DESCRIPTION

       The  tapeinfo  command  reads  various information from SCSI tape drives that is not generally available via most vendors' tape drivers. It
       issues raw commands directly to the tape drive, using either the  operating  system's  SCSI  generic  device  (	e.g.  /dev/sg0	on  Linux,
       /dev/pass0 on FreeBSD) or the raw SCSI I/O ioctl on a tape device on some operating systems.

       One  good  time	to  use 'tapeinfo' is immediately after a tape i/o operation has failed. On tape drives that support HP's 'tapealert' API,
       'tapeinfo' will report a more exact description of what went wrong.

       Do be aware that 'tapeinfo' is not a substitute for your operating system's own 'mt' or similar tape driver control program. It is intended
       to supplement, not replace, programs like 'mt' that access your operating system's tape driver in order to report or set information.

OPTIONS

       The first argument, given following -f , is the SCSI generic device corresponding to your tape drive.  Consult your operating system's doc-
       umentation for more information (for example, under Linux these are generally start at /dev/sg0 under FreeBSD these start at /dev/pass0).

       Under FreeBSD, 'camcontrol devlist' will tell you what SCSI devices you have, along with which 'pass' device controls  them.  Under  Linux,
       "cat /proc/scsi/scsi" will tell you what SCSI devices you have.

BUGS AND LIMITATIONS

       This program has only been tested on Linux with a limited number of tape drives (HP DDS4, Seagate AIT).

AVAILABILITY

       tapeinfo  is  currently	being maintained by Robert Nelson <robertnelson@users.sourceforge.net> as part of the 'mtx' suite of programs. The
       'mtx' home page is http://mtx.sourceforge.net  and  the	actual	code  is  currently  available	there  and  via  SVN  from  http://source-
       forge.net/projects/mtx.

SEE ALSO

       mt(1),mtx(1),scsitape(1),scsieject(1),loaderinfo(1)

								    TAPEINFO1.0 						       TAPEINFO(1)