This product bulletin summarizes the uses and built-in limits of the multiple configurable file systems in Cisco Application and Content Networking System (ACNS) Software 5.0 on supported Cisco Content Engine configurations.
All ACNS versions have used K=1000 for network bandwidth and K=1024 for memory, in keeping with usual industry practices. The tables in this document use K=1024 for disks, whereas usual industry practice is to use K=1000.
Since ACNS is converting over to the usual industry practice (K=1000 for disks) a future version of this document will include different data in these tables, simply because of the changed definition of K.
Like Cisco® ACNS Software 4.2, Cisco ACNS Software 5.0 has four different file systems that are optimized for different aspects of Cisco ACNS Software. The four separately configured file systems are CDNFS, CFS, MEDIAFS, and SYSFS. The amount of user-configurable disk capacity depends on which features are turned on concurrently, as explained in the following paragraphs.
Note: The CDNFS file system serves the same functions as the file system called ECDNFS in Cisco ACNS Software 4.2.
- CFSCFS is used by the HTTP caching and cache-preload subsystems to store cached HTTP objects. The ideal size depends on the HTTP traffic working set. Little-used objects cached in CFS may be discarded automatically to make room for more recently demanded objects (contrast with how objects are handled by CDNFS).
- CDNFSCDNFS is used by the Cisco Content Delivery Network (CDN) subsystem to store pre-positioned content. CDNFS can be zero if CDN capabilities are not used. If CDN capabilities are used, CDNFS must be at least 2 GB. Objects stored in CDNFS are retained until replaced or deleted by the CDN management system (contrast with how objects are handled by CFS).
- MEDIAFSMEDIAFS is used by streaming-media servers that support proxy-mode delivery (Real Proxy and Windows Media Technology [WMT] Proxy in Cisco ACNS Software 5.0) to cache streaming-media content. MEDIAFS can be zero if neither Real Proxy nor WMT Proxy is enabled. If either server is enabled, MEDIAFS must be at least 1 GB.
- SYSFSSYSFS is used by the content engine to store temporary files, logs, and debugging information. There must be exactly one SYSFS file system, and it must be at least 1 GB. A content engine with heavy HTTP traffic and logging on every transaction needs a bigger SYSFS. Typically, SYSFS needs at least 10 percent of "user-configurable capacity."
Note: No content is stored on the Cisco Content Distribution Manager (CDM) in Cisco ACNS Software 5.0. In contrast to Cisco ACNS Software 4.2, available disk space on the CDM should not be a significant factor in sizing a system.
Table 1 lists combinations of Cisco ACNS Software features that may be enabled. Each combination has a unique code number. Table 2 lists content engine configurations supported by Cisco ACNS Software 5.0. Each has a unique code letter.
A code letter alone is sufficient to determine the recommended SYSFS size and the remaining amount of space that can be allocated among CDNFS, CFS, and MEDIAFS. Subsequent tables require both a code letter and a code number to indicate the maximum possible space in each file system. Usually, maximizing the storage for any particular file system requires minimizing the storage available to others.
- "Real server" and "Real proxy" are enabled separately.
- "Windows media" enables both server and proxy capabilities for WMT.
- "Cisco streaming" enables server delivery of QuickTime and Motion Picture Experts Group (MPEG) formats.
- The Cisco Cluster Management Suite (CMS) enables management capabilities and is required for CDN deployments.
- HTTP caching is always enabled.
Table 1 Cisco ACNS Features
Table 2 Content Engine Configuration Table
|Code||Content Engine Model and Configuration|
Use Table 2 together with Table 3 to determine the appropriate letter. The numbers in each column of Table 3 indicate the recommended size for SYSFS in gigabytes, and the remaining configurable space that can be allocated among CDNFS, CFS, and MEDIAFS.
Table 3 Recommended SYSFS
Table 4 CDNFS Maximum Size
| - ,
 - ,
 - 
|All others: CDNFS not used|
Note: Where two numbers appear, the first number applies only to Cisco ACNS Software 5.0.1, and the second number applies to Cisco ACNS Software 5.0.3.
Note: Maximum CFS size may not yield the maximum caching performance. Caching performance also depends on the availability of sufficient memory.
Table 5 CFS Maximum Size
| - |
| - |
| - |
| - |
| - |
| - |
Table 6 MEDIAFS Maximum Size
MEDIAFS not used
| - ,
 - ,
| - ,
 - ,
 -