Solved

Does the SCSI READ CAPACITY command?

Posted on 2010-09-21
4
801 Views
Last Modified: 2012-05-10
Does the SCSI READ CAPACITY command value of block size is the block size set the File system block size?
0
Comment
Question by:areyouready344
  • 2
4 Comments
 
LVL 6

Accepted Solution

by:
Ferrosti earned 63 total points
Comment Utility
Your filesystem does not see the SCSI protocol, so these values are independend from one another.
0
 
LVL 30

Assisted Solution

by:Duncan Meyers
Duncan Meyers earned 62 total points
Comment Utility
http://en.wikipedia.org/wiki/SCSI_Read_Capacity_Command

Returns the block length in bytes. The block length is the block as written to the underlying device - for example, 64K for an EMC CLARiiON array, or 512 bytes for a singles disk on a SCSI controller.
0
 
LVL 47

Assisted Solution

by:dlethe
dlethe earned 125 total points
Comment Utility
No, this is the block size for the selected physical device, which is usually 512 bytes.  The CDB has no knowledge nor does it care about the file system, or even if the disk has data or a file system on it.  This is a simple CDB that reports number of addressable blocks on selected device.

To change block size, you need to use MODE SELECT command.
0
 
LVL 47

Assisted Solution

by:dlethe
dlethe earned 125 total points
Comment Utility
p.s. READ_CAPACITY returns both block size and # of addressable blocks, and there is both a 10-byte and 16-byte variation.  The 10-byte variation is only good for devices under the 2.09TB threshold.  16-byte variation of the command is now supported on most operating systems, but not all.
0

Featured Post

6 Surprising Benefits of Threat Intelligence

All sorts of threat intelligence is available on the web. Intelligence you can learn from, and use to anticipate and prepare for future attacks.

Join & Write a Comment

Lets start to have a small explanation what is VAAI(vStorage API for Array Integration ) and what are the benefits using it. VAAI is an API framework in VMware that enable some Storage tasks. It first presented in ESXi 4.1, but only after 5.x sup…
Learn about cloud computing and its benefits for small business owners.
This video teaches viewers how to encrypt an external drive that requires a password to read and edit the drive. All tasks are done in Disk Utility. Plug in the external drive you wish to encrypt: Make sure all previous data on the drive has been …
This tutorial will walk an individual through the process of installing the necessary services and then configuring a Windows Server 2012 system as an iSCSI target. To install the necessary roles, go to Server Manager, and select Add Roles and Featu…

772 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

11 Experts available now in Live!

Get 1:1 Help Now