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Disk Space and Memory

This appendix describes the memory requirements of the calendar server. These requirements can be broken down into two categories: database disk space requirements and run-time requirements involving virtual memory and swap space.

• Database disk space requirements
• Remote NFS storage
• Run-time requirements

Database disk space requirements

Server performance is influenced by disk configuration. To enhance the performance of the server, it is recommended that the application be allocated its own disk (/users/unison). Further enhancements can be obtained by devoting one or more disks for permanent user data (/users/unison/db/nodes) and temporary user data (/users/unison/db/tmp).

Each directory entry, whether for a local or remote item, requires 2 Kb of disk space. Local items require additional disk space for calendar data. The disk space requirements of a remote item are therefore considerably less than those of a local item, although the exact figure will depend on the usage of Corporate-Wide Services. Additional yearly disk space requirements of a local item can be estimated by determining the following values:

Table A-1 Variable definitions

Variable	Definition
DAYS_YEAR	number of work days in a year
ITEMS_EVENT	average number of items invited to an event
EVENTS_ITEM_DAY	average number of events attended by an item daily
GROUPS_ITEM	average number of groups created by an item
ITEMS_GROUP	average number of items in a group
SECURITIES_ITEM	average number of security privileges granted by an item
ATTACHED_STREAMS	average size of the comments and objects attached to an event
TASK_STREAMS	average size of the comments attached to a task
TASKS_ITEM_DAY	average number of tasks created daily by an item

Using the values that you determine for these variables, the following formula determines disk space, in bytes, attributed to a local item on a yearly basis:

disk space = 1631 +

(SECURITIES_ITEMS * 123) +

(GROUPS_ITEM * (335 + (ITEMS_GROUP * 63))) +

((((ITEMS_EVENT * 128) + 768 + ATTACHED_STREAMS) / ITEMS_EVENT) *

DAYS_YEAR * EVENTS_ITEM_DAY) +

(DAYS_YEAR*TASKS_ITEM_DAY * (1155 + TASK_STREAMS)))

Consider an example where the following values are set:

Variable	Definition
DAYS_YEAR	260
ITEMS_EVENT	7
EVENTS_ITEM_DAY	8
GROUPS_ITEM	50
ITEMS_GROUP	15
SECURITIES_ITEM	100
ATTACHED_STREAMS	512
TASKS_ITEM_DAY	3
TASK_STREAMS	256

disk-space = 1631 +

(100 * 123) +

(50 * (335 + (15 * 63))) +

(260 * 8 * ((768 + 512 + (7 * 128)) / 7) +

(260 * 3 * (1155 + 256)))

2,080,000 or 2 megabytes of disk space per user per year

One final note concerning disk-space: each active calendar user has temporary data files, located in /users/unison/db/tmp, whose combined size should not exceed 450 Kb.

Remote NFS storage

UNIX installations of Oracle Calendar server support linking the calendar database on a remote NFS file system. If you choose to do so, only the /users/unison/db directory may be stored remotely. All other directories must remain local.

Run-time requirements

The server run-time environment consists of four UNIX daemons/multi-threaded Windows NT services: the Lock Manager (unilckd), Engine (uniengd), Synchronous Network Connections (unisncd), Corporate-Wide Services (unicwsd), and a uniengd server for each active user. An additional UNIX daemon/multi-threaded Windows NT service, the Directory Access Server (unidasd), is included in installations using an external directory. At startup, with no connections, a total of 5 Mb RAM is used by the daemons/services. Each connection requires between 500 and 900 Kb RAM, dependent on hardware and configuration, for an Engine server/thread to service that client's requests. Use 750 Kb as a general benchmark. Contact Oracle support for more information on your chosen platform. The maximum number of concurrent users is set for an installation by the lck_users parameter, and the number of persistent connections to the directory server is set by the numconnect parameter in the /users/unison/misc/unison.ini file. Thus, the formula to calculate RAM requirements would be:

internal directory

5 Mb + (750 Kb * lck_users)

with directory server

5 Mb + (750 Kb * lck_users) + (300 Kb *( numconnect -1))