Uninterruptible Power Supply (UPS)

Do you need a UPS? YES!

A UPS is basically an additional insurance policy for your electronic equipment and vital for maximum life of your hardware. It will not only stop most power spikes and surges from getting to your hardware. A UPS can also provide a battery powered backup in the event of a power brown-out or blackout for a period of time as well as voltage correction if the power supply voltage is too high or too low.

While most businesses already have a UPS protecting their critical equipment, few households do. Small but capable UPS’s are now cheap enough that there is basically no reason to not get one. An entry level UPS is now under $100AUD but I would recommend spending around $150-250AUD for a home PC system to give a bit more battery run time.

The big names in UPS’s are APC (Americal Power Conversion) and Eaton. Eaton consumer grade UPS’s are branded as “Powerware”. There are some other good brands such as Nikko but there are also some cheap and nasty ones that should be avoided.

Things to look for when deciding what to buy:

• Easy battery replacment – Batteries are a consumable item and last 3-5 years, most UPS’s use readily available gel lead acid batteries
• Compatible sockets – APC tend to use the universal IEC C13 connector which need a IEC cable to connect to a device or a converted to connect to a powerboard, Powerware use Australian standard sockets.
• Connection (USB usually, network on commercial systems) to PC being protected – allows normal system shutdown when battery level gets critically low
• Run time and load requirements – Run time at full load is only a few minutes, if you want more run time, buy a bigger unit. APC has an online run time calculator to calculate run time for a load for their range of UPS’s. Larger commercial grade UPS’s can have extra battery packs added for extra run time.
• Online vs Line interractive – Most are line interractive (cuts over to battery if the supply fails) but some of these types do not like being run from a generator. If a generator backup is required (small petrol or diesel off the shelf unit, not purpose built), an online UPS (supply charges the internal battery and all output comes from the battery at all times) is generally better but also can be more expensive.

For extra surge protection, supply your UPS through a surge protected powerpoint or double adapter. Surge protection is cumulative, a single device may not be able to stop a big spike (>1000 Joules) but two or three (rated at 500+ Joules each) in line may be enough.

Openfiler

I have been playing around with Openfiler for the past few weeks. Basically Openfiler is an open source, customised Linux operating system specifically designed to be a file server, or more specifically, an “Open Source Storage Management Appliance” . It has far more functionality than simple file storage though, it can be an FTP server, a Network Attached Storage (NAS) server, and even an iSCSI SAN if you need one (I used it while testing a VMWare vSphere infrastructure system). It will run on pretty much anything x86/x64 based (min spec 1Ghz processor with 512MB RAM), can interface with a Windows domain and its web based interface is pretty simple to use so anyone looking for a simple and cost effective bulk storage solution should definitely have a look at it.

I had a test server (2x Xeon 2.8, 4GB RAM and 4x200GB SATA drives in RAID 5) to try it on. As I already had hardware RAID, I didnt need to implement software RAID but as it supports software RAID 0,1,5,6 or 10, I could have. One thing that caught me out was a limitation of 4 primary partitions on the drives. Apparently a normal implementation would have the Openfiler system (by default this is 4 partitions) on a single drive or array and it would be separate from the data storage. It is not recommended to have the OS and the data on the same disks as a restoration may be more challenging. As I already had a 4 disk RAID array ready to use, and this was for testing only I just installed to that and therefore I could not use any of my drives for data which kind of defeated the purpose. A reinstallation on the same array but with a manual partition creating an extended fourth partition rather than a primary gave me over 550GB of usage storage. Following the basic installation instructions, I found it relatively simple to create a usable NAS box. I did not add it to a Windows domain but think that it would actually be easier than having to configure the Openfiler device as its own LDAP server. FTP was also pretty easy to get up and running. You dont need to know any Linux at all, the initial installation is graphical (unless you want console) and after the initial installation, all configuration is done via a web browser.

Apparently if you plan to use it for production block level storage (iSCSI, SAN), you apparently should use a second network interface for management although in testing, I have not bothered and simply use it across my network with only minor performance issues. It is actually easier to set up as an iSCSI target than it was for NFS or FTP and is simple to connect to VMWare ESX (although I did need to reboot it after re-mapping LUN’s before ESX could connect to it as an iSCSI target even though it could see it). I also had no problems connecting my Windows 7 laptop to it either using the built in software iSCSI initiator with pretty good performance (30-50MB/s over gigabit ethernet)

To set up openfiler as an iSCSI SAN:
1a. Create Physical volume on a single disk OR
1b. Create RAID volumes on multiple disks and create array
2. Add volumes from #1 into a Volume Group
3. Create an iSCSI volume in the VG from #2
4. Start the “iSCSI target server” service
5. Add a network entry for the client machine (or local subnet if private) at the bottom of “System > Network Setup”
6. Click “iSCSI Targets” on the Volumes page
7. Click “Add” to create a new target.
8. Click “Lun Mapping”
9. Click “Map”
10. Click “Network ACL”
11. Change the combo box for your network to “Allow”.

I am not sure if I would roll this into production just yet but for a backup storage system, or bulk storage of non-critical files (I used to run a 250GB iTunes server at a music publishing company that could definitely benefit from this type of flexible storage), it could be very useful. There are purely commercial alternatives for production use such as Datacore SAN Melody but there is an active userbase of Openfiler which should be able to assist with and commercial support options are available if required.