Rackspace Cloud Servers has introduced a new architecture for Linux and Microsoft Windows servers called Performance Cloud Servers. This article describes some of the major features and benefits that this new offering provides:
Performance servers use faster solid state drives (SSD) and separate the system disk from the data disk, with both disks equally RAID 10 protected. With your operating system on a separate disk from your data, you can more easily create an image of the system disk because it is a fixed size and doesn't scale up as other resources increase. For more information on data disk imaging limitations, see Images Capture System Disk Only (below) or for the full procedure,see Creating an Image of Your Performance Cloud Server with the Control Panel. You can back up the data on your data disk or disks by leveraging either Rackspace Cloud Backup or Rackspace Cloud Block Storage (an option that can also be used to increase the storage capacity of your server, if needed). For a comparison of the two data disk backup options, see Best Practices for Backing Up Your Data: Cloud Block Storage versus Cloud Backup.
Dedicated 10-gigabit Ethernet (10 GigE) for networking on the host computer, SSDs, and no requirement to format the entire disk (system disk only) when building your servers will make the time to provision noticeably quicker.
Performance servers are available with RAM selection of up to 120 GB per server (up from 30 GB in the standard server class).
Performance servers provide more processing power: up to 32 vCPUs or virtual cores (compared to a maximum 8 vCPUs on the largest-size server in the standard server class). For information on the Performance Server types, see Two Performance Server Types: Performance 1 and Performance 2.
Performance servers provide more network bandwidth: 40 gigabit Ethernet (40 GigE) to each host server (the physical server where your Performance server exists). Each host server gets 20 GigE for management and Cloud Block Storage, and 20 GigE for the server's public network, ServiceNet, and network traffic. This bandwidth dramatically improves the interoperability of Performance servers with complementary services such as Cloud Block Storage over the standard server class.
Separating the operating system from the data provides higher maximum input/output operations per second (IOPS). For example, the 1 GB Performance server with 20 GB of system disk and no data disk can process about 20k IOPS. The 120 GB Performance server with a 40 GB system disk and 1200 (or 4x300) GB data disks can perform about 80k IOPS. Compare this with the standard server class for Cloud Servers, which can only process approximately 2k IOPS.
Performance 1 servers are best suited for applications that can benefit from bursting, including web servers, batch processing, network appliances, smaller databases, and most general-purpose computing workloads. Performance 1 servers use shared CPU and networking resources.
Performance 2 servers are assigned dedicated CPU and networking resources and have a higher maximum IOPS than Performance 1 servers. As a result, they are better suited for applications where consistently high performance is more valuable than the ability to take advantage of variable resources for bursting.
Changes have been implemented with Performance servers to align with industry standards, improve server imaging and consistently allocate adequate SSD resources for each server. The following paragraphs oultine these differences and how you can benefit from them.
One of the biggest differences between the standard servers and Performance servers is that Performance servers cannot dynamically resize. With the rest of the OpenStack community, Rackspace is reducing support for this feature because it does not align with the industry-standard method of scaling. Rather than resize one server for vertical scaling, we instead recommend employing horizontal scaling, adding or removing the number of servers managed by a load balancer, to manage your available resources to suit your needs. For information on changing your Performance Server's size, see Changing the Size of Your Performance Cloud Server.
Images or snapshots of your system capture your operating system's configuration (your system disk). This makes the imaging process run more quickly and reliably without placing undue strain on your server. To retain the information stored on your data disk, you can use Cloud Block Storage or Rackspace Cloud Backup to save only the files and directories that you need. For a comparison of the two options, see Best Practices for Backing Up Your Data: Cloud Block Storage versus Cloud Backup.
As a result of having a separate System Disk and Data Disk with Performance Servers, you will need to prepare your Data Disk by formatting and mount it to your server in order to be able to use it. Please follow the instructions in these articles to prepare your data disk for use:
The 512 MB RAM cloud server is not available for Performance Cloud Servers. As a server that uses shared CPU and networking resources, maintaining the 512 MB size would place too much stress on the host because of the bursting capabilities, and potentially negatively impact other servers on the host computer.
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