Hi all,
We have the following situation; a server equipped with VMware ESXi had a VM installed with CentOS/RHEL.
For security reasons this VM had to be reinstalled, however we chose to perform a side to side installation for easy-migration of data.
After setting up the new VM the disk performance was bad, the new VM had a different version of CentOS (5.4 instead of 5.3 compared to the old VM).
I figured this was due to disk interaction of both VM's, after deleting the first, the problem still occurs.
So then I thought; maybe this is a disk issue, so today I replaced the disk in order to get a quick machine again.
Due to the replacement of the disk, I had to reinstall ESXi and the VM.
Did that, but still the diskperformance is sooo bad.
Is there something i'm overseeing here?
Is the hardware faulty? (it's a DELL PowerEdge R200, with single disk, no RAID).
Any idea's, because I'm out by now
Gr, Mike
i think it's not a bad result, it depends you disks,
for example my VM with CentOS 5.4 on HP BL460c G1 with RAID1 on 146GB SAS disks:
/dev/sda:
Timing buffered disk reads: 106 MB in 3.02 seconds = 35.05 MB/sec
VM runs on not updated ESXi 4
Some extra info:
I also tried to install the same version that was already installed: CentOS 5.3
Still same issue...
I've tried to change the controller from LSI Parallel to LSI SAS
Still same issue...
And last but not least; i've updated the VMware host to the lastest version (patches).
But unfortunately, still same issue...
how do you test disk perfomance?
try hdparm -tT /dev/yourdisk
Is it using the perc 6 controller? does it have the battery-backup unit installed on it?
Please award points to any useful answer.
Hi,
I exactly did the test as you described earlier.
The read buffer is ok (3000+ MB/sec), but the buffered read is below 30MB/sec.
However, I did the check with just creating random files with a size of 100MB, 500MB and 1GB, it never came above 20MB/sec, most of the time it's actually less then that. So really performance to cry about...
Hi,
No this is just a base server. On-board controller of the DELL R200, with one disk attached.
This server isn't using a PERC or SAS controller.
The performance earlier was fine, after setting up the new VM's, it's really bad.
Double post :S
In my case configuring smaller main memory like 512MB per VM caused very poor performance in web browsing. As soon as I increased it to 2GB, performance dramatically improved. Hope this is the case of your environment.