Hi! I am running tests on our new test device. The device has 2x2 core Xeon, intel 5000 chipset, two 3ware sata raid card on pcie, and 15 sata2 disks, running debian etch. More info at the bottom. The first phase of the test is probing various raid levels. So i configured the cards to 15 JBOD disks, and hacked together a testing script. The script builds raid arrays, waits for sync, and then runs this command: iozone -eM -s 4g -r 1024 -i0 -i1 -i2 -i8 -t16 -+u The graphs of the results here: http://gergely.tomka.hu/dt/index.html And i have a lots of questions. http://gergely.tomka.hu/dt/1.html This graph is crazy, like thunderbolts. But the raid50 is generally slower than raid5. Why? http://gergely.tomka.hu/dt/3.html This is the only graph i can explain :) http://gergely.tomka.hu/dt/4.html With random readers, why raid0 slowing down? And why raid10 faster than raid0? http://gergely.tomka.hu/dt/2.html Why raid6 cant became faster, with multiple disks, as raid5 & 50? So lots of questions. I am generally surprised by the non-linearity of some results and the lack of acceleration with more disks on other results. And now, the details: Hardware: Base Board Information Manufacturer: Supermicro Product Name: X7DB8 Processor Information Socket Designation: LGA771/CPU1 Type: Central Processor Family: Xeon Manufacturer: Intel ID: 64 0F 00 00 FF FB EB BF Signature: Type 0, Family 15, Model 6, Stepping 4 (two cpus) Memory Device Array Handle: 0x0017 Error Information Handle: No Error Total Width: 72 bits Data Width: 64 bits Size: 1024 MB Form Factor: DIMM Set: 1 Locator: DIMM x 4 Bank Locator: Bank1 Type: DDR2 Type Detail: Synchronous Speed: 533 MHz (1.9 ns) Manufacturer: Not Specified Serial Number: Not Specified Asset Tag: Not Specified Part Number: Not Specified (two of this also) ursula:~# tw_cli show Ctl Model Ports Drives Units NotOpt RRate VRate BBU ------------------------------------------------------------------------ c0 9590SE-8ML 8 7 7 0 1 1 - c1 9590SE-8ML 8 8 8 0 1 1 - The tests generally: mdadm mkfs.xfs blockdev --setra 524288 md (maybe not a good idea for multiple arrays) do iozone test raid10 is two disks raid1s in raid0 and raid50 is three disk raid6s in raid0. These test runs for a week, and now slowly finishing. For this reason, replicatong the test to filter out accidents not a good option. Any comments? -- Tomka Gergely, gergely@xxxxxxxx - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
