Slow Transfer Rate - Over SATA or NETWORK

[CtrlData]

Hi,

Were new to VMware and we recently installed ESXi 4 on a Dell Poweredge 2900 (RAID 5 SAS, 20 GB RAM, 2 Processors). I'm attempting to copy a 30 GB file from my main DATASTORE onto a single SATA drive within the system and its going painfully slow. Previous to this I tryed to copy the same file across the network (GIGABIT NETWORK) to a Dell Workstation, its just as slow.

Question:

Why is VMware so slow at moving large files or am I doing something wrong?

-Michael

*************

Additional Information:

-(4) RAID 5, 146 GB, SAS, 15k RPM Drives

-VMFS to VMFS formated drives

The drive I'm transfering to is a 7200 RPM, SATA INTERNAL Drive, non-RAID

I'm showing about 30k per second, worse than a dial up connection.

[mike_laspina]

Hi,

Can you provide more detail about your configuration?

e.g.

Raid 5 with 6 SAS 1TB model x disk?

Copy from datastore VMFS to VMFS?

Using Datastore browser?

Regards,

Mike

http://blog.laspina.ca/

[CtrlData]

See my reply.

[mike_laspina]

Ouch!

It's messed up, what do you have for transfer rate from VM to VM?

You need to look at the vmware esx logs.

Enable Remote Tech SSH

login as root and issue

cat /var/log/messages

You should also look at the esxtop output - run exstop and hit the h key for options

Regards,

Mike

http://blog.laspina.ca/

[CtrlData]

I only have (1) virtual machine on running, I plan to import 3 more soon, but I've got to get this figured out. Is there any test I can run with just one machine installed?

[AndreTheGiant]

How are you perform the copy?

Which controller do you have? PERC and which one?

On the PERC (if battery is present) have you enabled the write back cache policy?

Andre

[CtrlData]

Ok,

Since we last talked, I've reinstalled ESXi and reloaded my Virtual Machines. I'm still getting very slow transfer rates between my SATA drive and the PERC 5 raid array. Also, the inbound transfer speed over my network from my desktop to the server was around 3-5mbps???

[idle-jam]

this is slow, have you ensure that the write back cache policy is enable on the perc card?

[DSTAVERT]

There were several suggestions and things to look into. Reinstalling doesn't help if you have other problems. As suggested make sure the RAID controller has a battery backed cache module and has write caching enabled. Run esxtop as suggested.

[mike_laspina]

The common element appears to be the SATA disk which is holding the source files. We need to rule out any issies on the ESXi host and storage.

Can you install iometer on the VM and bench it as a effort to see what the PERC transfer rate is at. please use 64k @ 100% write and then 100% read. 10 workers should be sufficient. 

Since this occurs over the network as well it is not likely an ESXi issue but it could be related to the ESXI COS VM being short on resource or a shared IRQ hardware issue.

Is a USB device active on the system?