View source for HacDC-shared-m335-1 Xen

OBSOLETE
Xen on Debian Stable gave some mysterious disk-controller errors, thoroughly confirmed not to be hardware problems. OpenVZ has been chosen instead.

Simple project server, emphasis on availability and uptime.

Most likely, this server will continue operating for several years, even as newer and better servers supplant it.

=Login=
On any unix terminal emulator, enter the command:
 <nowiki>
ssh <userName>@HacDC-shared-m335-1.hacdc.org
</nowiki>and
On other platforms, try applications like [http://www.chiark.greenend.org.uk/~sgtatham/putty/ PuTTY] with similar settings.

=CommandReference=
Routinely important commands unique to this server documented as follows.
==Root (Admin)==
===ReInstall===
* apt-get install xen-linux-system xen-tools git sudo
* dpkg-divert --divert /etc/grub.d/08_linux_xen --rename /etc/grub.d/20_linux_xen
* Installation of [https://github.com/mirage335/hostedXen hostedXen] .
* Uncomment lines referring to "-nat" and comment other vif-script/network-script lines in /etc/xen/xend-config.sxp .
* Uncomment "dir = /home/xen" in /etc/xen-tools/xen-tools.conf .

===hostedXen===
* ./hxNewUser <userName>     # Creates user account with default Xen VM and permissions.
* ./hxDelUser <userName>     # Deletes user account, associated VMs, and associated Xen permissions.
* ./hxNewVM <userName> <VM_Number> <dist> #     Creates VM accessible to non-root user <userName> .
===Autostart===
Through normal reboots, host will suspend/resume any guest VMs. If that is insufficient, the correct way to enable autostarting is through the xm command, [https://www.novell.com/support/kb/doc.php?id=3466408 documented as method 2 here].
===iptables===
====Investigation====
* iptables -t nat -L -n -v     #Lists port forwarding rules.
* iptables -t nat -F     #Deletes port forwarding rules.
* iptables -D PREROUTING 1     #Deletes port forwarding rule.

====Forwarding====
=====Enable=====
 <nowiki>
/sbin/iptables -P FORWARD ACCEPT
/sbin/iptables --table nat -A POSTROUTING -o eth0 -j MASQUERADE
</nowiki>

=====Specific=====
 <nowiki>
/sbin/iptables -t nat -A PREROUTING -p tcp -i eth0 --dport 20283 -j DNAT --to 10.174.10.5:22
</nowiki>

=====Persistent=====
Package iptables-persistent has been installed. Upon installation, existing iptables rules were saved. Edit /etc/iptables/rules.v4 .

==Users==
===List===
List Xen VMs created for you.
 <nowiki>
cat ~/xenList
</nowiki>
===Startup===
Start Xen VM, and launch console.
 <nowiki>
sudo /usr/sbin/xm create -c /etc/xen/<name>.cfg     #Escape with Ctrl+] .
</nowiki>
Just start Xen VM. Useful if planning to interact through other means (ie. network).
 <nowiki>
sudo /usr/sbin/xm create /etc/xen/<name>.cfg
</nowiki>

===Shutdown===
Yes, really, hard shutdown is termed "destroy". Don't worry, not synonymous with "delete".
 <nowiki>
sudo /usr/sbin/xm destroy <name>
</nowiki>
===Console===
Opens the console of running VM <name> .
 <nowiki>
sudo /usr/sbin/xm console <name>     #Escape with Ctrl+] .
</nowiki>

=Characteristics=
* CPU - E2200 Dual-Core 2.2GHz 
* RAM - 1GB
* HDD - 500GB
* Hostname - HacDC-shared-m335-1
* FQDN - HacDC-shared-m335-1.hacdc.org

=Redundancy (RAID)=
None yet, keep backups. Nonetheless, hard disk is kept cool, so the server should have a long life ahead of it.

=Policies=
==Permissions==
===Root===
HacDC members with a demonstrable need or willingness to manage non-root users may be given root access. Imperative that root users do not jeopardize uptime.
===Shell===
All HacDC members are welcome to non-root shell accounts, directly provided by the server, and used to manage Xen VMs.
===Xen===
All HacDC members are welcome to Xen Virtual Machines. Resources, including CPU, disk space, and external network ports, will be allocated on an as-needed first-come-first-serve basis.

Root users, please use the provided hostedXen scripts. Following the naming conventions set therein helps account for which resources belong to whom.

==Notifications==
Internal server email will notify users, if feasible, on the following schedules, subject to change.
* Three days before planned downtime exceeding one hour.
* One week before planned permanent downtime (obsolescence).

==Removal==
* Three months before removal of ex-member accounts. Exceptions on a case-by-case basis.
==DataLoss==
* Users should regularly backup critical data offiste.
* Onsite data storage is not guaranteed to be reliable.
* All server data may be deleted after obsolescence.
* Removed accounts may be deleted immediately and permanently upon deactivation.
==Privacy==
Machine is physically accessible to all keyholding HacDC members. Although HacDC members are generally responsible, privacy should not be expected.
==AcceptableUse==
===Sharing===
Sharing of account resources is permitted, however, additional resources will be allocated according to individual member needs for specific purposes. As a reminder, compromised accounts will be immediately removed as discovered.
===Bandwidth===
Hard bandwidth limits have not been set to ease administration of local file servers. However, please configure applications to limit maximum bandwidth use where possible, particularly for web servers.

=ChiefAdmin=
mirage335

=Credits=
Hunterkll - Donated core hardware.

=Special Services=
=Funtoo=
Funtoo (enhanced Gentoo) build server is available, with binary packages and weekly full-os tarballs for new installations.

=Softload=
https://github.com/mirage335/hostedXen

=Reference=
*https://wiki.debian.org/Xen#Domain_0_.28Host.29_Installation
*http://dev.e-taxonomy.eu/trac/wiki/Xen_installation
*http://wiki.xenproject.org/wiki/Nested_Virtualization_in_Xen#How_to_use_nested
*http://wiki.xen.org/wiki/Host_Configuration/Networking#Routing
*http://blog.manula.org/2012/04/manually-configuring-nat-networking-in.html
*http://www.fclose.com/816/port-forwarding-using-iptables/
*https://wiki.debian.org/iptables
*http://blog.manula.org/2011/02/xen-bridged-networking-mode.html
*http://xen.1045712.n5.nabble.com/console-access-to-non-root-xen-3-0-td2560667.html
*http://xen-tools.org/pipermail/xen-tools-discuss/2009-September/000674.html
*https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/5/html/Virtualization/sect-Virtualization-Tips_and_tricks-Limit_network_bandwidth_for_a_Xen_guest.html
*http://serverfault.com/questions/52027/how-can-i-limit-per-user-bandwidth
*http://www.howtoforge.com/nat-gateway-iptables-port-forwarding-dns-and-dhcp-setup-ubuntu-8.10-server
*https://major.io/2007/02/09/delete-single-iptables-rules/
*https://www.novell.com/support/kb/doc.php?id=3466408