Solved

Why are LTO autoloaders significantly more expensive with SCSI interface vs SAS?

Posted on 2010-11-10
3
633 Views
Last Modified: 2012-05-10
I was looking at prices on an HP LTO 4 Autoloader (HP), and the one with the SCSI LVD/SE interface is nearly $1000 more than the one with the SAS interface. Is there a reason for this?

We already have one LTO 3 autoloader with the SCSI interface, is it a bad idea to have one autoloader on SCSI and one on SAS on the same backup server, or is it best to have them both on SCSI?
0
Comment
Question by:Haunty
3 Comments
 
LVL 5

Assisted Solution

by:balasundaram_s
balasundaram_s earned 200 total points
Comment Utility
Parallel SCSI (LVD/SE) is faster than Serial SCSI ( SAS), so its expensive.
It depends on the environment, if data being copied from one tape drive to another, then I would prefer to have both same technology.
0
 
LVL 2

Author Comment

by:Haunty
Comment Utility
The interface on the autoloader I was looking at is Ultra-320 SCSI which is only slightly faster than SAS 3Gbps according to the specs, it doesn't seem to justify such a large cost difference.
0
 
LVL 20

Accepted Solution

by:
SelfGovern earned 300 total points
Comment Utility
I'm confused by balasundaram's comments, since you can have 6Gb SAS on many, many devices, but you'll be hard-pressed to find much that's 640MB SCSI (and they have essentially equal performance).  See http://en.wikipedia.org/wiki/Parallel_SCSI#Ultra-640

Parallel SCSI (pSCSI) became too complex of an implementation, because it requires that you get 32 signals from point A to point B within a very short time of each other, and without corruption or crosstalk... at about Ultra 320, it became clear that it would be easier to implement faster speeds over serial-attached SCSI (SAS) where you had one very, very fast signal without any of the crosstalk or synchronization issue.  For what it's worth, the same thing has happened inside your computer, where buses went from parallel (PCI) to serial (PCIe).

In answer to your question -- there's no issue with mixing pSCSI and SAS libraries in the same server.  With HP Libraries and autoloaders, I do recommend you load HP's free LIbrary and Tape Tools, and make sure your firmware is up-to-date periodically.  See http://www.hp.com/support/tapetools
0

Featured Post

IT, Stop Being Called Into Every Meeting

Highfive is so simple that setting up every meeting room takes just minutes and every employee will be able to start or join a call from any room with ease. Never be called into a meeting just to get it started again. This is how video conferencing should work!

Join & Write a Comment

Suggested Solutions

This article is an update and follow-up of my previous article:   Storage 101: common concepts in the IT enterprise storage This time, I expand on more frequently used storage concepts.
This paper addresses the security of Sennheiser DECT Contact Center and Office (CC&O) headsets. It describes the DECT security chain comprised of “Pairing”, “Per Call Authentication” and “Encryption”, which are all part of the standard DECT protocol.
This tutorial will walk an individual through the steps necessary to install and configure the Windows Server Backup Utility. Directly connect an external storage device such as a USB drive, or CD\DVD burner: If the device is a USB drive, ensure i…
This tutorial will walk an individual through setting the global and backup job media overwrite and protection periods in Backup Exec 2012. Log onto the Backup Exec Central Administration Server. Examine the services. If all or most of them are stop…

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

12 Experts available now in Live!

Get 1:1 Help Now