That is true, and the number of speeds depends (am I right on this?) on how the manufactuer implemented the LTO standard. Does anyone know if there is a way to monitor/poll/capture what speed the drive is operating at a given time?
On 9/13/07, Austin Murphy <[EMAIL PROTECTED]> wrote: > > Yes. Few drives are actually completely variable speed. The LTO > drives from IBM can write at 5 different fixed speeds, from half speed > to full speed. > > See page 55 of the PDF here: > http://www.redbooks.ibm.com/abstracts/sg245946.html > It describes Dynamic Speed Matching on IBM's LTO3 drives. > > IBM's TS1120 has 6 speeds. (page 77) > > This article compares the T10k and the TS1120 and mentions the write > speeds. > http://www.clipper.com/research/TCG2005077.pdf > > Austin > > On 9/13/07, Paul Keating <[EMAIL PROTECTED]> wrote: > > Isn't this true for most of the high end drives? > > None of them are "variable" speed, but will write at one of 2 or 3 fixed > > speeds. > > > > > > -- > > > > > > > -----Original Message----- > > > From: [EMAIL PROTECTED] > > > [mailto:[EMAIL PROTECTED] On Behalf > > > Of Austin Murphy > > > Sent: September 12, 2007 5:23 PM > > > To: Brad Hillebrand > > > Cc: veritas-bu@mailman.eng.auburn.edu > > > Subject: Re: [Veritas-bu] STK T10000 tape drive > > > > > > > > > I don't use them, but I did some research. > > > One gotcha that I came across was the writing speed. They can only > > > write at either 120 MB/sec or 50 MB/sec. There is no in between. Your > > > disk staging or virtual tape better be able to spit out the data at > > > one of those rates or the thing will shoe-shine like crazy. > > > > > > LTO-4 drives are likely to be easier to feed data and a lot cheaper. > > > I haven't compared prices with the hardware encryption options, but > > > w/o the encryption the drive prices are something like $5k vs. $30k. > > > > > > Also LTO-4 native capacity is 800 GB vs 500 GB for the T10k. Both can > > > write at 120 MB/Sec. > > > > > > Austin > > > ==================================================================================== > > > > La version française suit le texte anglais. > > > > > ------------------------------------------------------------------------------------ > > > > This email may contain privileged and/or confidential information, and > the Bank of > > Canada does not waive any related rights. Any distribution, use, or > copying of this > > email or the information it contains by other than the intended > recipient is > > unauthorized. If you received this email in error please delete it > immediately from > > your system and notify the sender promptly by email that you have done > so. > > > > > ------------------------------------------------------------------------------------ > > > > Le présent courriel peut contenir de l'information privilégiée ou > confidentielle. > > La Banque du Canada ne renonce pas aux droits qui s'y rapportent. Toute > diffusion, > > utilisation ou copie de ce courriel ou des renseignements qu'il contient > par une > > personne autre que le ou les destinataires désignés est interdite. Si > vous recevez > > ce courriel par erreur, veuillez le supprimer immédiatement et envoyer > sans délai à > > l'expéditeur un message électronique pour l'aviser que vous avez éliminé > de votre > > ordinateur toute copie du courriel reçu. > > >
_______________________________________________ Veritas-bu maillist - Veritas-bu@mailman.eng.auburn.edu http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
