Now Im puzzled, I wasnt aware of the fact you have to pay for an PAV license. I didnt read the whole "story".
I was sure, that PAV is only an eckd-linux-driver bussiness, wich isnt developed/released yet. Perf: The goal is, to get the most perf, lowest response time, best scalabilty, and of course the most stable out of that, what is given to you. Some special features may be suitable for special environments, but unfortunately many salespersons an buyers calculating cost/performance ratio exactly like its named. Cost/Performance... but lets deal again with the subject: Maybe it would help too, when you are able to get the system disks, (v)swap disks (also Swap of VM) an the ext3-journal of your big fs away from the certainly heavy utilized CHPIDs. Stripe as much as you can. logical and physical. You loose the flexibility of growing... I think the performance of an M9 disk isnt important. We benchmarked striped M3 and M9 pvs, same LVM-layout, had 4 and 8 phys. escon-channels. Nearly Same perf-values. Aren't the DASDs virtual in the storage boxes?? Tracks are living anywhere!? regards fs > Frank Schwede > Lufthansa Systems Infratec GmbH > mailto:[EMAIL PROTECTED] -----Urspr�ngliche Nachricht----- Von: Linux on 390 Port [mailto:[EMAIL PROTECTED] Auftrag von Rob van der Heij Gesendet: Dienstag, 20. Juli 2004 09:09 An: [EMAIL PROTECTED] Betreff: Re: WG: Performance of large file systems Frank Schwede, LSY wrote: >Im sorry, but: >What is going on here? > >I was sure, someone would give a statement about the real current state of PAV on >Escon DASDs. > > Maybe others were puzzled like myself. Why the &$* would you pay for PAV license on the ESS and not invest in FICON? When all response times are cut so drastically, the trouble of waiting in queue is less dramatic. If you need to decide between small disks and large ones with PAV, can think of scenario's where the PAV solution is better. With such large filesystems you already took the cost of LVM anyway. The benefit of striping does depend a lot on application behaviour, and it is easy to make it counter productive. I am having a hard time trying to come up with proper benchmarks to compare scenario's. This is complicated and there are so many variables, each answer that I find gives me two more questions. Rob ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390 ---------------------------------------------------------------------- For LINUX-390 subscribe / signoff / archive access instructions, send email to [EMAIL PROTECTED] with the message: INFO LINUX-390 or visit http://www.marist.edu/htbin/wlvindex?LINUX-390
