VMware CLOUD DIRECTOR 1.0 Instrukcja Użytkownika Pobierz pdf (Strona 15)

PERFORMANCE STUDY /15

VMware vCloud Director 1.0 Performance and Best Practices

Here are some examples that show how the TCP receive window size affects bandwidth utilization:

•

For a DSL network:

the bandwidth delay product = bandwidth × roundtrip delay = 512Kbps × (100ms × 2 ÷ 1000)s = 12.8KB

Here, we take the DSL bandwidth from the previous table, 512Kbps. To get the roundtrip delay, we multiply

the DSL latency from the previous table (100ms) by 2 because we need to measure the latency to and from

the destination. Then we divide the product by 1000 to convert milliseconds to seconds.

This is well within the TCP maximum receive window size of 64KB.

•

For a satellite network:

the bandwidth delay product = 1.5Mbps × (500ms × 2 ÷ 1000)s = 1.5Mb = 192KB

This is bigger than the TCP maximum receive window size of 64KB, so 1.5Mbps is not fully utilized.

Sizing and Performance Tuning Tips

For OVF file upload, the vCloud Director server temporarily stores the OVF packages before they are transferred

to ESX hosts. The required disk space for the temporary buffer is determined by two elements. One is the

maximum number of concurrent OVF package uploads; the other is the file size for each OVF package. For

example, if at the peak, 20 concurrent transfers are expected, and each OVF package contains about 10GB VMDK

files, the required space is 20 × 10GB = 200GB. In a WAN environment, because an OVF transfer might take

longer to finish, the disk requirement for OVF upload can be larger because there may be more OVF packages

that are in the transfer state.

The same disk space could also be used for cloning vApps across vCenter Server instances. In that case, the disk

requirement should also include how many concurrent vApp clone operations could occur and how big each

vApp is. The next section describes how to achieve the best performance for cloning vApps across vCenter

Server instances.

If a file upload fails in the middle of a transfer between the client and the cell, the temporary files are kept in the

cell for some time. As a consideration for that, we recommend adding 20% disk space. The following is a sizing

formula:

disk size = max number of concurrent transfers × average file size × 1.2

Here,

max number of concurrent transfers

includes both OVF file transfers and other file transfers caused by

operations such as those initiated by cloning vApps across vCenter Server instances.

Because this disk buffer is very I/O intensive, we recommend separating it from the logging disk of the vCloud

Director server. This can be done by NFS mounting. This way, the disk operations can be separated from the cell

logging and OVF file uploads.

1 2 ... 10 11 12 13 14 15 16 17 18 19 20 ... 31 32

Brak uwag

VMware CLOUD DIRECTOR 1.0 Instrukcja Użytkownika Strona 15