Transfer Rate Disk Post: 302505635

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Top Forums UNIX for Dummies Questions & Answers Transfer Rate Disk Post 302505635 by Corona688 on Thursday 17th of March 2011 01:16:04 PM

03-17-2011

Registered User

dd is a general purpose data moving command. It's sometimes used for moving data from one raw disk to another but it's a flexible command and doesn't care what kind of files or devices it's talking to.

dd by itself just reads stdin and writes back to stdout, so dd < filename > newfile is effectively the same thing as cp.

It does it in blocks of 512 bytes by default, which is a bit inefficient, so dd bs=1048576 < filename > newfile may be much faster. Beyond a certain point making the buffer bigger doesn't help.

So all I'm doing is having dd read from one file and write to another, and while it's running, sending it the signal SIGUSR1 which casues it to print statistics. Or you could wait for it to end, or kill it with ctrl-C, and it'll print statistics as it ends.

cache effects are when the OS doesn't immediately store what you've written to file on disk, just in memory. This is great for programs since they don't have to wait for the disk to catch up but troublesome for benchmarks. dd in linux supports the oflag=sync option to tell it not to do that.

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LEARN ABOUT SUNOS

hpfc

hpfc(7D)							      Devices								  hpfc(7D)

NAME

       hpfc - Agilent fibre channel host bus adapter

SYNOPSIS

       PCI   pci103c

DESCRIPTION

       The hpfc fibre channel host bus adapter is a SCSA compliant nexus driver that supports all Agilent fibre channel host bus adapters, includ-
       ing the HHBA5100x, HHBA5101x, and HHBA5121x models. Agilent host bus adapters support the fibre channel protocol on private  fibre  channel
       arbitrated loops and fabrics. The driver supports up to ten host bus adapters, with a maximum of 125 fibre channel devices on each host bus
       adapter. The hpfc driver supports a maximum of 256 LUNs per target.

       The hpfc driver does not support the BIOS Int 13 feature, which enables the booting of an operating system. As a  result,  you  should  not
       install an operating system on devices attached to the hpfc driver.

CONFIGURATION

       The hpfc driver attempts to configure itself using the information in the /kernel/drv/hpfc.conf configuration file.

       By default, the driver supports only LUN 0 for each target device. To add multiple LUN support, modify the /kernel/drv/sd.conf file.

       Before  upgrading the hpfc driver, backup the sd.conf file to save customized LUN settings and then use pkgrm(1M) to remove the old version
       of the driver.

       The host bus adapter port is initialized to FL_Port when connected to a fabric switch. To change it  to	F_Port,  add  the  init_as_nport=1
       entry to the hpfc.conf file and reboot the system.

       To  conserve system resources, at least one disk drive must be attached to the hpfc driver. If no devices are attached, the driver will not
       load.

FILES

       /kernel/drv/hpfc 	       32-bit ELF kernel module

       /kernel/drv/sparcv9/hpfc        64-bit ELF kernel module

       /kernel/drv/hpfc.conf	       Driver configuration file

       /kernel/drv/sd.conf	       SCSI disk configuration file

ATTRIBUTES

       See attributes(5) for descriptions of the following attributes:

       +-----------------------------+-----------------------------+
       |      ATTRIBUTE TYPE	     |	    ATTRIBUTE VALUE	   |
       +-----------------------------+-----------------------------+
       |Architecture		     |x86, SPARC		   |
       +-----------------------------+-----------------------------+

SEE ALSO

       luxadm(1M), pkgrm(1M), prtconf(1M), driver.conf(4), attributes(5), ses(7D), ssd(7D)

       ANSI X3.272-1996, Fibre Channel Arbitrated Loop (FC-AL),

       ANSI X3.269-1996, Fibre Channel Protocol for SCSI (FCP),

       ANSI X3.270-1996, SCSI-3 Architecture Model (SAM),

       Fibre Channel Private Loop SCSI Direct Attach (FC-PLDA)

SunOS 5.10							    10 Oct 2000 							  hpfc(7D)