I have the following configuration: simple video surveillance system (server 1: recording past 24h; server 2: recording past 30 days). I am primarily using the content on the 24h storage, while I recompress and archive the following 30 days on the other server. My idea is to use RAID 1+0 for server 1 (for better performance & reliability) and RAID5 for server 2 (for lower cost). Is this a good plan or there are better [...]

I’m very confused. If I setup a Reverse Proxy Server, does this mean that I need a second computer? Or can both Server (e.g. nginx as reverse proxy server and apache as webserver) run on the same computer and different port!? For example this pic! it seems to me that there are 4 computers (one for each server) ? Asked by Matthias Reisner “A server is a process” said to me a teacher years ago [...]

I am trying to make a simple network architecture for a small company. One of the sites is built of a firewall (to create a DMZ, to make the VPN between the sites) and three switches, like in link below. http://i.stack.imgur.com/ot1yJ.png There are workstations connected to each of the switches. It is a VLAN-based network. Employees obtain their addresses with DHCP server. The company has got also another site, connected with a VPN/IPSec tunnel. My [...]

So recently a client asked me to build her a virtual calendar. She’s tired of having paper ones and would rather hang a few monitors on the wall instead and have them update themselves wirelessly. The key constraints for this device: – Must be no bigger than a monitor – Must be quick to turn on/off – Must have wireless capability – Ideally low power The task falls to me, then, to find the hardware [...]

… like running a PPC or ARM system on x86 hardware. As far as I know: VMWare can’t QEMU can KVM can because it uses QEMU Is this correct? What other solutions are there? That’s not virtualisation, that’s emulation. Virtualisation can be seen as a specific kind of emulation where you emulate the same machine on itself, accelerating the emulation by letting some of the instructions run for real. Your question should just be “What [...]

I have seven Sites. Each Site contains about 15 to 20 users who are connect via ADSL and lease line. My question is how to design a network infrastructure. To Solve above problem I Create One Domain Controller & Additional Domain Controller in Head Office. ADSL Line is connected to Sonicwall. Sonicwall provide the VPN connectivity. Lease Line is configure by using Cisco 3600 Router.On Site a place Sonicwall and establish VPN connectivity with Head [...]

An architect in our company has designed a solution based on 64 bit SQL2005 Standard edition synchronous mirroring between a physical (4 quad core, 32GB RAM) server and a virtual DR server (4 virtual CPUs with 16GB RAM) in two geographically remote data centers with a witness server (1 virtual CPU). Storage is Enterprise class SAN in both data centers. The front end app is web facing with mixed read/write usage. As a DBA (who [...]

I’m reconfiguring some mail architecture and wondering about this… For the purposes of avoiding blacklists and maintaining a good MX reputation, is it better to have: One public IP / SMTP server dedicated to outbound only e-mail Another public IP / SMTP server dedicated to inbound only e-mail Or both incoming/outgoing on one IP? It makes no difference, inbound routes won’t be considered when assigning reputation. Reputation used by email spam filtering providers (one of [...]

It’s a big question:) We are running a website with LAMP that is not big, 5 web servers with LVS load balancing, 3 MySQL servers with replications and separation of reading and writing, and we use Memcached for caching and some full-text searching tools. So far it works well because we do not have a large traffic for the moment. But when the users are growing rapidly, we will have to scale our architecture to [...]

This is a gentoo server. There’s a programme prog that can’t execute. (Yes the execute permission is set) About the file $ ls prog $ ./prog bash: ./prog: No such file or directory $ file prog prog: ELF 32-bit LSB executable, Intel 80386, version 1 (SYSV), for GNU/Linux 2.2.5, dynamically linked (uses shared libs), not stripped $ pwd /usr/local/bin $ /usr/local/bin/prog bash: /usr/local/bin/prog: No such file or directory $ less prog | head ELF Header: [...]