On 01/13/2014 05:26 AM, Digimer wrote: > On 13/01/14 04:49 AM, Digimer wrote: >> Hi all, >> >> I'm trying to sort out a significant performance hit I am getting >> with a LUKS partition inside a KVM VM (host is RHEL 6.5, guest is also >> RHEL 6.5). >> >> Inside the VM, I get ~1.1 GB/sec write speed: >> >> ==== >> Inside the VM! (48 GB, 4x vCPUs, 500MB /boot, 40 GB /, 4 GB <swap>, RHEL >> 6 minimal, no selinux/iptables) >> Write to raw partition using: sync; dd if=/dev/zero of=/dev/vda5 bs=4M >> count=80000; sync >> - 335544320000 bytes (336 GB) copied, 302.885 s, 1.1 GB/s >> - 335544320000 bytes (336 GB) copied, 293.905 s, 1.1 GB/s >> - 335544320000 bytes (336 GB) copied, 289.298 s, 1.2 GB/s >> >> Write to ext4 partition using: sync; dd if=/dev/zero >> of=/mnt/data/zeros.out bs=4M count=80000; sync >> - 335544320000 bytes (336 GB) copied, 290.855 s, 1.2 GB/s >> - 335544320000 bytes (336 GB) copied, 347.901 s, 964 MB/s >> - 335544320000 bytes (336 GB) copied, 317.877 s, 1.1 GB/s >> ==== >> >> When I created the LUKS partition though, I got substantially lower >> speed: >> >> ==== >> [root@vm01-ng-rhel01 ~]# cryptsetup -v status vda5 >> /dev/mapper/vda5 is active. >> type: LUKS1 >> cipher: aes-cbc-essiv:sha256 >> keysize: 256 bits >> device: /dev/vda5 >> offset: 4096 sectors >> size: 1729118208 sectors >> mode: read/write >> Command successful. >> >> (killed the 'dd' when I realized how slow it was going) >> >> sync; dd if=/dev/zero of=/dev/mapper/vda5 bs=4M count=80000; sync >> 48330964992 bytes (48 GB) copied, 345.72 s, 140 MB/s >> ==== >> >> I noticed that the real CPU on the host: >> >> ==== >> vendor_id : GenuineIntel >> cpu family : 6 >> model : 62 >> model name : Intel(R) Xeon(R) CPU E5-2637 v2 @ 3.50GHz >> stepping : 4 >> cpu MHz : 3500.087 >> cache size : 15360 KB >> physical id : 1 >> siblings : 8 >> core id : 4 >> cpu cores : 4 >> apicid : 41 >> initial apicid : 41 >> fpu : yes >> fpu_exception : yes >> cpuid level : 13 >> wp : yes >> flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca >> cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall >> nx pdpe1gb rdtscp lm constant_tsc arch_perfmon pebs bts rep_good >> xtopology nonstop_tsc aperfmperf pni pclmulqdq dtes64 monitor ds_cpl vmx >> smx est tm2 ssse3 cx16 xtpr pdcm pcid dca sse4_1 sse4_2 x2apic popcnt >> tsc_deadline_timer aes xsave avx f16c rdrand lahf_lm ida arat epb >> xsaveopt pln pts dts tpr_shadow vnmi flexpriority ept vpid fsgsbase smep >> erms >> bogomips : 6998.99 >> clflush size : 64 >> cache_alignment : 64 >> address sizes : 46 bits physical, 48 bits virtual >> power management: >> ==== >> >> Has a lot more features (I see 'aes' in particular) than inside the VM: >> >> ==== >> processor : 3 >> vendor_id : GenuineIntel >> cpu family : 6 >> model : 13 >> model name : QEMU Virtual CPU version (cpu64-rhel6) >> stepping : 3 >> cpu MHz : 3499.998 >> cache size : 4096 KB >> fpu : yes >> fpu_exception : yes >> cpuid level : 4 >> wp : yes >> flags : fpu de pse tsc msr pae mce cx8 apic sep mtrr pge mca cmov >> pse36 clflush mmx fxsr sse sse2 syscall nx lm unfair_spinlock pni cx16 >> hypervisor lahf_lm >> bogomips : 6999.99 >> clflush size : 64 >> cache_alignment : 64 >> address sizes : 46 bits physical, 48 bits virtual >> power management: >> ==== >> >> Should I (can I?) be passing some of these features up to the guest to >> improve LUKS performance? >> >> Thanks! > > I copied the extensions of the host, and 'aes' showed in the guest's cpuinfo, > to the VM and got somewhat better numbers; > > Write to raw LUKS partition using: sync; dd if=/dev/zero of=/dev/mapper/vda5 > bs=4M count=80000; sync > - 335544320000 bytes (336 GB) copied, 1157.27 s, 290 MB/s > > Still a far cry from what the base system can do. > For all questions like this, please start with sudo virsh dumpxml $vmname, and /var/log/libvirt/qemu/$vmname.log - Cole _______________________________________________ virt-tools-list mailing list virt-tools-list@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/virt-tools-list
