I wonder...
Are those speeds measured in a pristine lab environment with the drives idle ? 
Or in a real-world setting when the drives are all pumping data @ max data 
rates when fast robotics are actually needed....

A more important number to know/measure/reveal would be what percentage of 
those 'implemented' units are still in use a year or two after being installed. 
And of those units that have been replaced, what were they replaced with ? (I'd 
bet it was not another SL500)

The one users experience of having to replace the robotics 8 times in 2 years 
definitely points to a serious design flaw and/or very poor materials choice 
for physically stressed parts.... Or maybe he just got a lemon ?

I think the best measure of performance for a tape library / silo is the trial 
by fire method and/or the long term experience of the majority of the users who 
work with them on a daily basis... 

Kind of like autos, Toyota touts the very high percentage of Corrolas ever sold 
still on the road being driven daily... That's a real-world, experience based 
statistic that is difficult to counter... 


> -----Original Message-----
> From: EMC NetWorker discussion 
> [mailto:NETWORKER AT LISTSERV.TEMPLE DOT EDU] On Behalf Of Attila
> Sent: Friday, February 20, 2009 11:02 AM
> To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
> Subject: Re: [Networker] Upgrade to LTO4 library, opinions 
> about these libraries ?
> 
> Let me also provide you some numbers for the StorageTek SL500 
> library regarding robotic speed.
> Sorry to se some people are unhappy with it, but this may be 
> not very representative as since the introduction 3-4 years 
> ago, more than 11.000 units has been implemented worldwide.
> 
> Exchanges per hour, base unit 50 slots (drive to cell to 
> drive), average
> 53 sec, (exchanges per hour = 67)
> Exchanges per hour, all 5 modules (drive to cell to drive), 
> average 67 sec, max 83 Exchanges per hour, base unit 50 slots 
> (cell to cell and back), average 20 sec Exchanges per hour, 
> all 5 modules (cell to cell and back), average 24 sec, max 29 
> Access time from cartridge to drive, base unit 50 slots, 
> avarage 12 sec Access time from cartridge to drive, all 5 
> modules, avarage 13 sec, max 16 Audit time - Open/close door 
> to "ready" state, 6 min with 50 slots, 31 min with all 5 
> modules and 18 drives
> 
> regards  -attila
> 
> --
> ********************************************************************
> Attila Mester                           5 Digit Sun internal: x62534
> Data Protection Architect                  Tel: (+49 89) 46 008 2534
> Sun Microsystems GmbH                      Fax: (+49 89) 46 008 2583
> Sonnenallee 1                                Mobil: +49 172 812 5947
> 85551 Heimstetten / Germany              mail: attila.mester AT sun DOT com
> ********************************************************************
> 
> 
> 
> Clark, Patti schrieb:
> >  We have 2 Quantum i500 libraries.  One has been in use 
> since November, the other will be in production next month.  
> The one that we've been using replaced a Quantum M2500 with 
> LTO-2 drives.  The i500 has been flawless, the picker is much 
> faster over the M2500.  We are very happy with the i500 and 
> would recommend it to anyone.  We have one dual-channel fibre 
> hba at this time.  The controller shares one of the tape 
> drive channels for communications.  We'd had 2-dual channels 
> SCSI hbas for the LTO-2 library, but we had to retain one of 
> the hbas for the controller (Dell daughter card) to manage 
> the disk drives.  I mention this because we have 3 IBM tape 
> drives in the i500, but can only access 2 of them at this 
> time.  Even with that, the LTO-4 drives are so much faster, 
> that we are completing our largest backups in less time than 
> with 3 LTO-2 drives, about 1/3 - 1/2 less time.
> >
> > While we have a couple of SANS here, our backups are all 
> server-based file systems.  Our networker server is RHEL4 on 
> a Dell 2850.  We use v7.4.3 Networker.
> >
> > You didn't indicate whether you were planning on using tape 
> encryption or not.
> >
> > Patti Clark
> > DOE/OSTI
> >
> >   
> >> -----Original Message-----
> >> From: EMC NetWorker discussion 
> >> [mailto:NETWORKER AT LISTSERV.TEMPLE DOT EDU] On Behalf Of Manel Rodero
> >> Sent: Friday, February 20, 2009 6:47 AM
> >> To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
> >> Subject: [Networker] Upgrade to LTO4 library, opinions about 
> >> these libraries ?
> >>
> >> Hello,
> >>
> >> We're evaluating different offers por changing our old library (a 
> >> Qualstar TLS6460 with 60 slots/4 drives SDLT320) to a new 
> >> LTO4 library 
> >> with FC interfaces.
> >>
> >> Our initial idea is to connect the library (i.e. its 2 
> initial LTO4 
> >> drives) directly to the server using a dual channel HBA 
> >> interface, but 
> >> we are evaluating the connection to our SAN too (for having 
> >> some hosts 
> >> direct backup to the library like storage nodes).
> >>
> >> We have different offers by our providers and we would like 
> >> to hear your 
> >> opinions about these libraries (support, problems, 
> evolution, etc.):
> >>
> >> * SpectraLogic Spectra T120 (30 slots, 2xLTO4,
> >> * Quantum Scalar i500 (41 slots, 2xLTO4, I/O magazine 6 slots)
> >> * Dell PowerVault ML6010 (41 slots, 2xLTO4, I/O magazine 6 slots)
> >> * Sun StorageTek SL500 (30 slots, 2xLTO4, CAP magazine 5 slots)
> >>
> >> Thank you very much!
> >>
> >> -- 
> >>
> >> o o o  Manel Rodero Blánquez             | LCFIB - FIB - UPC
> >> o o o  IT System Manager                 | Campus Nord - Modul B6
> >> o o o  Barcelona School of Informatics   | Jordi Girona, 1-3
> >> U P C  Technical University of Catalonia | 08034 Barcelona (Spain)
> >>                                           |
> >>         manel AT fib.upc DOT edu                 | Tel: +00 34 93 401 0847
> >>         http://www.fib.upc.edu/           | Fax: +00 34 93 401 7040
> >>
> >> To sign off this list, send email to 
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> >> the body of the email. Please write to 
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> >>
> >>     
> >
> > To sign off this list, send email to 
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> networker-request AT listserv.temple DOT edu if you have any 
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> >   
> 
> 
> -- 
> ********************************************************************
> Attila Mester                           5 Digit Sun internal: x62534
> Data Protection Architect                  Tel: (+49 89) 46 008 2534
> Sun Microsystems GmbH                      Fax: (+49 89) 46 008 2583
> Sonnenallee 1                                Mobil: +49 172 812 5947
> 85551 Heimstetten / Germany              mail: attila.mester AT sun DOT com
> ********************************************************************
> 
> To sign off this list, send email to 
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> 

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