How much did you paid for this? On 20/02/2012 07:26 AM, Bob Puff wrote: > Hi Gang, > > I recently rented a server at a datacenter with Centos 5.7 X64, Q9550 > Processor, 8GB Ram, and dual 250GB SATA HDs (with 16mb cache). They had > loaded it with KVM, and installed a 30-day trial of Virtualizor as the > front-end for KVM. > > I was so impressed with how fasts the guests ran that I want to build a few of > these machines for myself. I just installed one: same Q9550 processor, 4GB > ram, and dual 250GB SATA HDs (with 32mb cache). I installed Centos 6.2 X64, > and installed Webmin's Cloudmin as the front-end. > > Immediately when I was installing stuff, I could tell this new system I just > built was not nearly as fast as the first one. I ran some CPU and disk > benchmarking programs, and saw that while the CPU stuff tested similarly, the > disk thruput was much different... Down-right poor in one of the guests! > > On both systems, /dev/md2 is a LVM reserved exclusively for KVM guests. So > each guest is running in its own logical volume, in software raid. > > Thinking there may be something wrong with the HDs, I ran Bonnie ( > http://www.coker.com.au/bonnie++/ ) and compared both host machines. They > tested fairly similar (within 10%). Yet comparing their guests is like night > and day. Example: > > On good machine's Centos 5.7 x32 guest install: > # hdparm -tT /dev/hda > > /dev/hda: > Timing cached reads: 26760 MB in 1.99 seconds = 13417.10 MB/sec > Timing buffered disk reads: 388 MB in 3.01 seconds = 128.86 MB/sec > > On my machine's Centos 5.7 x32 guest install: > # hdparm -tT /dev/hda > > /dev/hda: > Timing cached reads: 1864 MB in 2.16 seconds = 863.87 MB/sec > Timing buffered disk reads: 358 MB in 3.08 seconds = 116.17 MB/sec > > On one of my machine's Mandrake 8.2 x32 guest install: > # hdparm -tT /dev/hda > > /dev/hda: > Timing buffer-cache reads: 27000 MB in 2.00 seconds = 13500.00 MB/sec > Timing buffered disk reads: 12 MB in 3.66 seconds = 3.28 MB/sec > > On that system, the hdparm's -i output shows: > # hdparm -i /dev/hda > > /dev/hda: > > Model=QEMU HARDDISK, FwRev=0.12.1, SerialNo=QM00001 > Config={ Fixed } > RawCHS=16383/16/63, TrkSize=32256, SectSize=512, ECCbytes=4 > BuffType=DualPortCache, BuffSize=256kB, MaxMultSect=16, MultSect=16 > CurCHS=16383/16/63, CurSects=16514064, LBA=yes, LBAsects=73400320 > IORDY=yes, tPIO={min:120,w/IORDY:120}, tDMA={min:120,rec:120} > PIO modes: pio0 pio1 pio2 > DMA modes: sdma0 sdma1 sdma2 mdma0 mdma1 mdma2 > UDMA modes: udma0 udma1 udma2 udma3 udma4 *udma5 > AdvancedPM=no > Drive conforms to: ATA/ATAPI-5 published, ANSI NCITS 340-2000: > > * signifies the current active mode > > The bonnie numbers show for sequential output: > Good Machine Host: 76,857K/Sec > My Machine Host: 72,561K/Sec > > Good Machine Centos 5.7 Guest: 66,266K/sec > My Machine Centos 5.7 Guest: 20,623K/sec > My machine Mandrake Guest: 1,365K/sec > > Where should I look? I realize I do have two different front-ends to KVM, and > perhaps they are passing different parameters to it. I am also running the > KVM from Centos 6.2 on my machine, vs the other server is running on 5.7, but > I would have thought that "newer is better". Also note that my hard drives > have a larger cache. > > > On a side note, I'm not thrilled with the Virtualizor's tech support, but the > product seems easy to use, once it actually works. Cloudmin seems to be > buggy, and not let you do things like change cd images on the fly, access the > console before the machine fully boots (!)... Any suggestions on other, > preferably open-source options? I'm a definite newbie to this virtualization > stuff. > > Bob > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos