Servers

Comms Mundi™ server sizing guide.

In order to ensure the required stability of a Comms Mundi™ system, is it important to choose the appropriate hardware redundancy options in the server.

Apply the following recommendations in order, given the budged available:

• Hard disk: Having at least two disks in RAID-1 (mirror) configuration is essential for any type of project.
  • Software RAID: Comms Mundi™ can configure software mirroring (RAID-1 soft) if it detects 2 disks of the same size on installation.
  • Hardware RAID: Performance and stability can be improved using a RAID card offering redundancy levels (RAID-1, RAID-5, RAID-10, …), memory and battery
• CPU / Memory: A professional CPU (ex: Intel Xeon) with ECC memory is highly recommended.
• Power Supply Unit: A redundant PSU is recommended if possible.

When sizing CPU for a project, maximum frequency and number of cores are not the only metrics to take into consideration. Also take into account:

• Generation: Newer generation of CPUs are generally faster and more reliable for the same number of cores and frequency.
• Features:
  • Memory bus: Number of channels and frequency of bus can make an important speed difference.
  • ECC Memory support: Error-correcting code memory is only supported in certain CPUs.
  • Multi-CPU: Not all CPUs support being installed in multi-CPU servers.
  • Encryption: Intel AES-NI or equivalent features can multiply VPN capacity by many folds.
  • Virtualization: Intel VT or AMD SVM are required features to install virtual machines in Comms Mundi™.

Hint: An interesting metric to compare general CPU speed can be http://www.cpubenchmark.net/

In terms of memory size, consider the following recommendations:

• Minimum requirements: A minimum of 4GB of memory should be considered for production servers with minimal usage.
• Recommended: A size of 8GB should be comfortable for most “non-extreme” scenarios.
• Performance: Comms Mundi™ uses memory for disk-caching and other performance related improvements. More memory means better performance.
• Virtual machines: Any amount assigned to a virtual machine is reserved, thus unusable by other tasks. In order to host a machine with 2GB, Comms Mundi™ requires at least 6GB.

Choosing between traditional electromechanical magnetic disks (HDD) and solid state disks (SSD) depends on project requirements:

• SAS vs SATA: While practical differences (in speed and reliability) between both buses are few, SAS compatible disks tend to be more reliable because of SAS being a traditional “enterprise-grade” bus.
• SSD vs HDD: Current enterprise-grade SSD are reliable enough to be used in servers, and offer impressive speed improvements over magnetic disks (HDD), but require a higher budget.
• Disk size: Disk size should be considered given needs to store user data:
  • System usage: Comms Mundi™ reserves 50GB of disk space for system.
  • Minimum requirements: Minimum size requirements is 100GB, enough for 50GB of user data
  • User data: Take the following into account when considering disk size
    • Voice: For voicemail, recordings and other sound or music files, count ~1MB per minute in wav, or ~100KB per minute in mp3
    • Fax: Count from 1KB to 150KB per page, mean of ~25KB per page
    • Other: Do not forget virtual machine disks (configurable), proxy cache (configurable), and user-uploaded data.

Scenarios:

• Generic usage: 1-20 users
• PBX / Softswitch: 1-10 simultaneous calls, <0.5 calls per second
• VPN: <20Mbps bandwidth
• Hotspot: 1-50 users

Recommendations:

• CPU: Intel Celeron/Pentium G3320, AMD Turion
• Memory: 4GB
• Disk: Two disks in RAID-1 software
• Example models:
  • HP MicroServer G7
  • Dell T30

Scenarios:

• Generic usage: 20-200 users
• PBX / Softswitch: ~10-100 simultaneous calls, 1-2 calls per second
• VPN: 20-100Mbps bandwidth
• Hotspot: 50-200 users

Recommendations:

• CPU: Intel Xeon E3-12XXv2 or better
• Memory: 8GB
• Disk: Two disks in RAID-1 software or better (RAID-1 hardware)
• Example models:
  • Dell T30 with Intel Xeon E3-1225v2
  • HP Proliant ML310e Gen8

Scenarios:

• Generic usage: 200-1000 users
• PBX / Softswitch: 100-500 simultaneous calls, 2-5 calls per second
• VPN: 100-300Mbps bandwidth
• Hotspot: 200-800 users

Recommendations:

• CPU: Intel Xeon E5-16XXv3 or better
• Memory: 16GB
• Disk: Two disks in RAID-1 hardware or better
• Example models:
  • HP Proliant DL360p Gen8
  • Fujitsu Primergy RX300 S8