<damjan.pipan.list@xlab.si>
2008-Oct-22 10:36 UTC
RE: [Xen-users] domains gets stalled for N seconds - problem with DMA?
Hi, I still have problems with io performance. Please tell me if I am doing something wrong. It seams that Xen can not run two domains with a lot of IO usage - a lot of requests not transfer? Tests: I have 8 SAS drives and 8 SATA drives. I have created: - 7 SAS in RAID6 and installed dom0 on this volume group - 7 SATA in RAID6 and installed domain-1 on this volume group - 1 SAS as volume and installed domain-2 on this volume group I have set the scheduler credits - dom0 - 60000 - dom1 - 1 - dom2 - 1 1 case: ====dom1 - write few hundreds of files per minute. dom2 - idle IT WORKS NORMALLY - few percent of wait/user in dom1 2 case: ====- dom2: tar xfz file.tgz with 3 milion of small files (1 KB) The domain 1 in this case get from 30-100% wait time. IMPORTANT: - dom1 and dom2 are on different arrays. - I run also top -d .5 on dom0 ---> it is usually idle but sometimes process blkback.17.sda1 gets to the top just for a moment (17 is ID of dom-2) - I checked also xm top and dom1 is 0 CPU usage when top in dom1 shows 100 wait time ---- Hardware/software is 2 * Intel(R) Xeon(R) CPU E5450 @ 3.00GHz Adaptec 31605 controller uname -a: Linux xen-de 2.6.18.8-xen #2 SMP Fri Jun 27 21:27:02 UTC 2008 x86_64 GNU/Linux host : xen-de release : 2.6.18.8-xen version : #2 SMP Fri Jun 27 21:27:02 UTC 2008 machine : x86_64 nr_cpus : 8 nr_nodes : 1 cores_per_socket : 4 threads_per_core : 1 cpu_mhz : 3000 hw_caps : bfebfbff:20100800:00000000:00000140:000ce3bd:00000000:00000001 total_memory : 16382 free_memory : 1028 node_to_cpu : node0:0-7 xen_major : 3 xen_minor : 2 xen_extra : .1 xen_caps : xen-3.0-x86_64 xen-3.0-x86_32p hvm-3.0-x86_32 hvm-3.0-x86_32p hvm-3.0-x86_64 xen_scheduler : credit xen_pagesize : 4096 platform_params : virt_start=0xffff800000000000 xen_changeset : unavailable cc_compiler : gcc version 4.1.2 20061115 (prerelease) (Debian 4.1.1-21) cc_compile_by : root cc_compile_domain : xlab.si cc_compile_date : Fri Jun 27 23:35:01 CEST 2008 xend_config_format : 4 _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users