HP HOWTO: Utilisation and Configuration Guide of HP Products under Linux
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Internet/Intranet Linux server

Web Server

The Web service uses 2.5 MB of RAM, in static mode (simple HTML pages) and 5 MB of RAM in dynamic mode (HTML pages generated from per, php, ...) per user. The disk space needed is function of the nature of the server, knowing that most of the consumption comes from images. Processor resources used are important, thus it could be useful to consider the increase in frequency and the addition of processors, because this type of traffic could be quite well done in parallel. We will priviledge also the I/O speed with Ultra 2 LVD SCSI at 80 MB/s, if the budget allows it, and 10.000 RPM disks.

Table 4-3. Sizing of a static Web server

Simultaneous users	RAM size	Disk size	Machine example
1 - 100	256 Mo	9 Go	E60
100 - 500	1 Go	9 Go	LC2000 Bi-processeur
500 - 1000	2 Go	9 Go	LH4 Quadri-processeurs

Table 4-4. Sizing of a dynamic Web server

Simultaneous users	RAM size	Disk size	Machine example
1 - 100	512 Mo	9 Go	E60
100 - 500	2 Go	9 Go	LC2000 Bi-processeur
500 - 1000	4 Go	18 Go	LH6000 Quadri-processeur

Mail Server

Generally, this machine is used as both SMTP (sending and reception of messages) and POP server (keeper of messages and manager of client accesses). The SMTP Mail service uses 2 MB of RAM per user. The POP Mail service uses 2 MB of RAM per user. The disk space needed becomes more and more important as long as attachments (images, various documents) take the greatest place in exchanges via e-mail. We consider in that case that an average mail box size is 50 MB. Processor resources used are important, thus it could be useful to consider the increase in frequency and the addition of processors, because this type of traffic could be quite well done in parallel.

Table 4-5. Sizing of an e-mail server

Simultaneous users	RAM size	Disk size	Machine example
1 - 100	400 Mo	9 Go	E60
100 - 500	2 Go	27 Go	LC2000 Bi-processeur
500 - 1000	4 Go	54 Go	LH6000 Quadri-processeur

Firewall/Proxy/Web-Cache server

Generally, this machine is both a Firewall server, a proxy (in both directions) and a cache for the Web because all requests go through it. The Firewall service uses 1 MB of RAM. The Proxy service uses 0.3 MB per incoming relay. The Web cache service uses 0.5 MB per user. The disk space needed is function of the parameters of the cache Web server. In that case, we consider 20 MB per user. Processor resources used are important, due to the analysis of IP packets. Thus it could be useful to consider the increase in frequency.

Table 4-6. Sizing of a Firewall/Proxy/Web-Cache server

Simultaneous users	RAM size	Disk size	Machine example
1 - 100	128 Mo	9 Go	E60
100 - 500	512 Mo	18 Go	E60
500 - 1000	1 Go	27 Go	E60