Veritas-bu

[Veritas-bu] Multiplexing

2002-05-21 20:39:33
Subject: [Veritas-bu] Multiplexing
From: peter.urbanec AT csfb DOT com (Urbanec, Peter)
Date: Wed, 22 May 2002 08:39:33 +0800
Larry Kingery:
> I still wish I knew if you had to keep DLT drives
> streaming DURING READ.

You don't "HAVE TO", but it certainly does make a significant difference to the 
performance. It also depends on how much slower your client runs in comparison 
to the drive and the drive buffer size.

Worst case scenario is when the time to reposition the tape is greater than the 
time to empty the buffer, yet your aggregate speed is much lower than the read 
speed. i.e. very bursty I/O

Large buffers tend to iron out the bursts a bit.

        Peter Urbanec    B.Sc.(Comp.Sci.)  UNSW
        mailto:peter.urbanec AT csfb DOT com





This message is for the named person's use only. It may contain sensitive and 
private proprietary or legally privileged information. No confidentiality or 
privilege is waived or lost by any mistransmission. If you are not the intended 
recipient, please immediately delete it and all copies of it from your system, 
destroy any hard copies of it and notify the sender. You must not, directly or 
indirectly, use, disclose, distribute, print, or copy any part of this message 
if you are not the intended recipient. CREDIT SUISSE GROUP and each legal 
entity in the CREDIT SUISSE FIRST BOSTON or CREDIT SUISSE ASSET MANAGEMENT 
business units of CREDIT SUISSE FIRST BOSTON reserve the right to monitor all 
e-mail communications through its networks. Any views expressed in this message 
are those of the individual sender, except where the message states otherwise 
and the sender is authorized to state them to be the views of any such entity.
Unless otherwise stated, any pricing information given in this message is 
indicative  only, is subject to change and does not constitute an offer to deal 
at any price quoted. Any reference to the terms of executed transactions should 
be treated as  preliminary only and subject to our formal written confirmation.



<Prev in Thread] Current Thread [Next in Thread>