Yes, correct that it's rated at that max speed. But if you don't have a pipe big enough to handle the max speed, the other question is how small can the pipe be before it becomes problematic and unusable. I just checked, and according to Fuji, an IBM LTO4 drive will speed match down to 30MB/sec, which means you will still be able to get some useful work done with a smaller pipe.
http://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=1&ved=0CDIQFjAA&url=http%3A%2F%2Fwww.fujifilmusa.com%2Fshared%2Fbin%2FLTO_Overview.pdf&ei=i6IaUYuHGqn-0gHlmIGwDQ&usg=AFQjCNFcZqFcjcsiAWUCkWiXcmVwqbUgJQ&bvm=bv.42261806,d.dmQ&cad=rja ..Paul At 02:38 PM 2/12/2013, Shawn DREW wrote: >LTO4 is rated at 120MB/s max speed, which comes out to just under 1gbit/sec >(1gbit/s = 125MB/s). I normally reserve 1gbit for each LTO4 drive. (i.e. 4 >drives on a 4gb HBA) >I do see 110+MB/s streaming on those guys. (using topas -T on AIX, so not >sure about the accuracy) > > >Regards, >Shawn >________________________________ >Shawn Drew >> -----Original Message----- >> From: ADSM-L@VM.MARIST.EDU [mailto:ADSM-L@VM.MARIST.EDU] >> Sent: Tuesday, February 12, 2013 12:04 PM >> To: ADSM-L@VM.MARIST.EDU >> Subject: Re: [ADSM-L] 1 GBit FC sufficient for tape library? >> >> Another thought: You really want to avoid the LTO4 drives dropping out of >> streaming mode, even if 1Gb/s is enough bandwidth to theoretically move >> the amount of data you need to move. I believe LTO4 will operate down to >> 30-40MB/s. Worth checking, since I'm not sure, but I'm pretty sure you can >> drop as low as 40MB/s and still stay in streaming mode. Once you drop out of >> streaming mode, your throughput will go in the dumper, and you won't get >> anything close to 1Gb/s throughput. >> >> At 10:15 AM 2/12/2013, Michael Roesch wrote: >> >Hi Stefan, >> > >> >one quick question: what are the numbers you are using for your >> >calculation? >> > >> >Did you convert 240 MB/s into Gigabit/s? >> > >> >Thanks >> > >> >Regards, >> >Michael >> > >> > >> > >> >On Tue, Feb 12, 2013 at 1:01 PM, Stefan Folkerts >> ><stefan.folke...@gmail.com>wrote: >> > >> >> Yes, two LTO4 drives would not be happy at all behind a 1Gb/s HBA, >> >> even two 1Gb/s HBA's are not enough to fully utilize the drives. >> >> I would imagine you could also run into driver/firmware issues with >> >> this combination since it's a very strange one but then again....it >> >> would probably work just slow. >> >> >> >> >> >> On Tue, Feb 12, 2013 at 12:34 PM, Michael Roesch >> >> <michael.roe...@gmail.com>wrote: >> >> >> >> > Hi Stefan, >> >> > >> >> > the drives are LTO4 ones. So the HBA would be the bottleneck >> >> > >> >> > >> >> > On Tue, Feb 12, 2013 at 11:36 AM, Stefan Folkerts < >> >> > stefan.folke...@gmail.com >> >> > > wrote: >> >> > >> >> > > If it is LTO1 or LTO2 you would be OK, if it is LTO3 or higher >> >> > > you are limiting your drivers with your HBA. >> >> > > >> >> > > >> >> > > On Tue, Feb 12, 2013 at 10:39 AM, Michael Roesch >> >> > > <michael.roe...@gmail.com>wrote: >> >> > > >> >> > > > Hi all, >> >> > > > >> >> > > > we have an old HP MSL 6030 with two drives that share one 1 >> >> > > > GBit FC >> >> > port. >> >> > > > Would that be enough to use with TSM? I have a feeling that says >> "no" >> >> > > but I >> >> > > > couldn't find any minimum FC requirements. >> >> > > > Anyone having more info? Maybe even an IBM technote? >> >> > > > >> >> > > > Thanks >> >> > > > >> >> > > > Regards, >> >> > > > Michael Roesch >> >> > > > >> >> > > >> >> > >> >> >> >> >> -- >> Paul Zarnowski Ph: 607-255-4757 >> CIT Infrastructure / Storage Services Fx: 607-255-8521 >> 719 Rhodes Hall, Ithaca, NY 14853-3801 Em: p...@cornell.edu > > >This message and any attachments (the "message") is intended solely for >the addressees and is confidential. If you receive this message in error, >please delete it and immediately notify the sender. Any use not in accord >with its purpose, any dissemination or disclosure, either whole or partial, >is prohibited except formal approval. The internet can not guarantee the >integrity of this message. BNP PARIBAS (and its subsidiaries) shall (will) >not therefore be liable for the message if modified. Please note that certain >functions and services for BNP Paribas may be performed by BNP Paribas RCC, >Inc. -- Paul Zarnowski Ph: 607-255-4757 CIT Infrastructure / Storage Services Fx: 607-255-8521 719 Rhodes Hall, Ithaca, NY 14853-3801 Em: p...@cornell.edu