Hi Manfred, On 27 Mar, Manfred Koizar wrote: > Mark, > > how often did you run your tests? Are the results reproduceable? In this case, I've only done 1 per each combination. I've found the results for this test to be reproduceable. > On Fri, 26 Mar 2004 14:00:01 -0800 (PST), markw@osdl.org wrote: >> Linux-2.6.3, LVM2 Stripe Width >> (going across) >>PostgreSQL >>BLCKSZ >>(going down) 16 KB 32 KB 64 KB 128 KB 256 KB 512 KB >>2 KB 2617 2656 2652 2664 2667 2642 >>4 KB 4393 4486 4577 4557 4511 4448 >>8 KB 4337 4423 4471 4576 4111 3642 >>16 KB 4412 4495 4532 4536 2985 2312 >>32 KB 3705 3784 3886 3925 2936 2362 > > Unless someone can present at least an idea of a theory why a BLCKSZ of > 8 KB is at a local minimum (1 or 2% below the neighbouring values) for > stripe widths up to 64 KB I'm not sure whether we can trust these > numbers. > > Before I hit the send button, I did a quick check of the link you > provided. The links in the table contain the following test numbers: > > 16 KB 32 KB 64 KB 128 KB 256 KB 512 KB > 2 KB 72 71 70 69 66 65 > 4 KB 64 63 62 61 60 58 > 8 KB 54 53 52 51 50 49 > 16 KB 79 78 77 76 75 74 > 32 KB 86 85 84 83 82 80 > > Does this mean that you first ran all test with 8 KB, then with 4, 2, 16 > and 32 KB BLCKSZ? If so, I suspect that you are measuring the effects > of something different. Yes, that's correct, but why do you suspect that? Mark _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
