Right--it seems that getting accurate measurements of end-to-end throughput data is nontrivial. How do you measure this? (I'm aware of one research group in Louisiana that has written software to measure end-to-end network performance, taking DMA, RAM, etc into account, but I don't know if this is available.)
On Sun, Jul 18, 2010 at 7:14 PM, Dustin J. Mitchell <[email protected]> wrote: > On Sun, Jul 18, 2010 at 6:34 PM, Florian Lengyel > <[email protected]> wrote: >> However, a SAS drive can deliver 300 Mb/sec (theoretical); in practice >> 270 Mb/sec >> is more likely. I have neither the drive nor the server with the >> disks, so I am guessing. >> I imagine a RAID5 SAS disk configuration with at least 3 disks would >> be suitable >> for a holding disk with 2 LTO5 drives. Either that or a fully-loaded MD1000 >> with >> SATA drives. > > Keep in mind that your SAS and LTO5 won't talk to one another > directly, so all of that data will need to get into and out of RAM - > hopefully via DMA, but still traversing PCI, SCSI, SAS, FC, RAID, etc. > > Dustin > > -- > Open Source Storage Engineer > http://www.zmanda.com >
