A virtual server is a separate Linux computer that runs as a guest of a physical Linux computer. Each virtual server is a complete Linux system including a kernel, RAM, swap, disk, and installed packages.

We run User-mode Linux in "SKAS" (Separate Kernel Address Space) mode. To further enhance security, we run our virtual servers in "chroot jail's".

Incredibly. With the exception of hardware access, you can do just about everything in a virtual server that does not require modifications to the kernel. All of the services that we supply on the Internet are actually running production inside of UML virtuals. These include production web services, database servers for admin functions, e-mail, etc.

Our virtual servers have Redhat 7.3 installed running on a stock, kernel.org, 2.4.20 kernel.

Yes you are. User-mode Linux is a complete Linux computer running as a guest task on the underlying host system. When you are root, you are really root with a UID of 0 running standard libs, etc. This is why you can use virtual Linux servers anywhere you would use a standard, dedicated, Linux server.

We configure systems with "virtual RAM" sizes ranging from 32 Megabytes to about 490 Megabytes (this is the limit in "non hi-mem" mode for User-mode-linux).

This depends on the hosting plan that you have selected. On most plans we configure a swap partition that is equal in size to your RAM size. With some configurations, the swap file is twice as large.

Standard virtual systems have two partitions. Partition 0 contains an "ext3" formatted filesystem that is the root filesystem for your virtual system. Partition 1 is a swap partition.

If you are running one of our small, low-cost servers, no. If you need more space, you will need to move to a larger hosting plan. Of course, with virtual servers, this is really quite easy technically.

For our larger servers, we can configure an additional Linux partition within the virtual server. This partition is then setup so that it is sub-managed within the virtual system with LVM (Linux Volume Manager). Thus you can then create multiple volumes, do snapshot backups, etc. The additional LVM volumes can be formatted ext2, ext3, reiserfs, or left as "bare" partitions for database use.

No. We are very careful to configure system with adequate resources (particularly RAM) to host the virtuals that reside on a physical host. For example, if we have 20, 32Meg virtuals, this would require 640Meg of physical memory. We would run these 20 virtuals on a host system with 1 Gigabyte of RAM giving each virtual it's own, essentially dedicated, memory.

Your system comes with a default firewall based on the "iptables" package. This firewall restricts inbound connections to:

• ssh
• http
• https
• ftp
• webmin

and outbound connections to:

• ssh
• domain

This firewall is typically so restrictive that even if your system is compromised, most Internet worms will not know how to "phone home".

You have complete control over the firewall and can open any communication port that you wish (or delete the firewall entirely if desired).

All of our datacenters have Internet connections to multiple providers. Each provider assigns us a block of IP addresses on their networks. We make these addresses available to your virtual server in a number of way.

Backup path for ssh - We supply you with a free backup IP address that you can SSH to to access your server. This SSH access uses a nonstandard TCP port number (it is not port 22) but is otherwise a full-bandwidth connection to your server.

MultiPath http/https - We give you a free mirroredhosting.com account including MultiPath web services. Within this account, you can setup directory mount points that "reverse-proxy" requests into your virtual server.

MultiPath e-mail - Your mirroredhosting.com account also includes e-mail services allowing you to receive and forward e-mails into your virtual server on a domain-by-domain or user-by-user basis.

There are a number of reasons for this:

• Many services are already setup and are easier to use than running them inside of your virtual.
• Standard services like static-content HTTP, DNS, and EMAIL are more efficient and take fewer system resources than running a separate copy of these within your virtual.
• Services running in MirroredHosting.com don't slow down your virtual or use resources from your virtual.
• Services running in MirroredHosting.com are "better" than what you are likely to setup on your virtual server:
  • Apache is tuned for maximum performance
  • DNS services are replicated across five servers at multiple locations
  • E-mail is full-featured with unlimited mailboxes, POP3, IMAP, WebMail, and optional virus/spam filtering.
  • Look over the MirroredHosting.com FAQ for more information.
• The MirroredHosting.com services are more reliable because they are running on mirrored servers with redundant Internet connections.
• You can use any amount of space that you need in MirroredHosting.com without "disk full" messages. Space over the 100 Megabytes allocated is billed at $1/25Megabytes ($40/Gig).

We believe that the two are extremely complimentary to each other. Basically, we recommend that you run the following functions inside of your MirroredHosting.com account:

• DNS
• Static HTTP and HTTP web pages
• EMAIL

And run all of your dynamic application code inside of your virtual.

The MirroredHosting.com admin application lets you "proxy" web directories within any domain. A "proxy" is where the web server acts as a relay and passes the transaction through to a second web server. The second web server in this case is your virtual server.

You set this up by defining a "proxy directory" such as:

Proxy: http://www.mydomain.com/app ==> http://v-2374.easyco.net/

Requests from the public directed to the /app directory in the www.mydomain.com domain name will actually be serviced by the web server running on your virtual system. The presence of your virtual server is completely transparent and hidden from the user (this is a proxy, and not a redirect). Because the user is communicating with our mirrored servers, they get the advantage of MultiPath and server mirroring.

Another advantage of this is that it lets you take your virtual server application down (lets say you need to do some programming) while still leaving you with a static web site so that your users can still get to your content.

We monitor packet transmissions every minute on our side of your network interface. This allows us to count bytes directly "on-wire".

Various hosting plans differ, but all get at least 5 Gigabit (which is quite a lot).

Additional transfer varies with the hosting plan, but starts at only $5/Gigabyte.

With local backups, we have a process that nightly makes a complete save of your system and saves this on a separate computer system located in the same facility as your virtual server. Backups are automatically rotated and you have two choices:

• Standard - keep the last 2 days plus the last 2 end-of-week saves.
• Enhanced - keep the last 3 days, the last 4 end-of-week, and the last 3 end-of-month saves.

A mirrored system involves taking your last backup and actually restoring it to another running virtual server to act as an immediately available backup server. This 2nd virtual server might be local or remote depending on the account type that you have. The advantage of a mirrored server is that you have less downtime and guaranteed system availability in the case of catastrophic failures at our data centers.

Your backups (both local and remote) are available to you via password protected "rsync". rsync is a UNIX tool that is designed to replicate directories between systems. It is extremely powerful and effective at copying very large directory structures, both locally and remotely. With rsync you can restore any file, directory, or even an entire system from your own backups quickly and easily.

Yes, but we highly recommend that you use "SSH" (Secure SHell) instead. SSH gives you the functionality of Telnet without transmitting data in the clear. Many commercial terminal emulators include SSH support as well as a number of "free" packages as well. Visit openssh.org for more information on SSH.

Security on the Internet is important and we highly recommend that you use secure protocols like SSH, scp, https, sftp, pop3s, imaps, etc. whenever possible.