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
>
>
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