On Sun, 8 Jul 2012 03:27:55 -0400, Steve Litt said: > On Sat, 07 Jul 2012 11:36:02 +0200, Reindl Harald said: > > > > > > Am 07.07.2012 11:23, schrieb Wojciech Puchar: > > >>> Fine. i understand that. What i am suggesting is not making > > >>> large LUNs. you get the best performance with directly > > >>> attaching disks to your machine. > > >> > > >> That's simply not true. 99% of block latency is rotational. > > >> iSCSI > > > It's not about iSCSI latency and overhead. > > > > > > It's about other things i just don't want to explain anymore for > > > people that just have to much money to spent to make things more > > > complex and less efficient. It's just stupid, but it's OT so EOT > > > > what are you trying to tell us here? > > > > do you REALLY believe you local disks can outperform a > > SAN storage with 1 GB dedicated buffer cache und a > > DEDUCATED 1400 MHz CPU which is only optimized for > > one task: disk performance > > > > you lcal storage has to fight for CPU and memory all > > teh time with other applications (caching etc.) > > > > to believe under really high load a local storage > > is faster at the end is bullshit! > > Can one even argue on one side or the other without knowing the speed > of the network, and how much contention is on that network? > > My experience is that with a 100Mbs network, local is faster, although > I've never had a SAN, so to speak, on the other end. > > The specification of a SATA rev 3 is 6Gbs, which is a heck of a lot > faster than 1Gbs per second spec of a gigabit network. Both have a lot > of things slowing them from their spec, but I'd need to see some proof > of an assertion that anything coming in over a 1Gbs wire can beat a > SATA rev3 local disk.
This isn't really a fair comparision because I don't think rev3 is commodity yet. So Rev 2, which IS commodity, is 3Gbs, which is still considerably faster than the wire on a Gigabit network. Thanks SteveT Steve Litt * http://www.troubleshooters.com/ * http://twitter.com/stevelitt Troubleshooting Training * Human Performance