Is a UPS required?

[campbela]

Hi All,

I have been playing around with FreeNAS for a while now and have spent quite a bit of time trawling through the various posts to help build up a reasonal amount of knowledge to help decide if I want to migrate from my existing setup to FreeNAS 8.

Currently I have a Windows 2003 server with an Adaptec SATA raid card with two 1TB drives setup in a hardware raid mirror. I have had this setup for about 3-4 years with no problems.

I have a new HP Microserver with a couple of 250GB drives in there which are setup in a software raid mirror (ZFS). This setup is for playing with before I get 2 2TB drives.

I have read a number of posts from people that have had problems after a power outage which leads me to my question: Do I need a UPS?

I have had power outages with my current setup and it has never caused any problems. I just boot up the server when the power is back on and carry on as normal. Is software raid more susceptible than hardware raid when the power fails?

Thanks

Alan

 

[KitDavis]

If you are asking if you should have a UPS between your server and the power source the answer (IMO) is a definite yes. And, it doesn't make any difference what kind of server you have. Most modern servers can handle an abrupt power outage, but brownouts (when the voltage spikes down and then back up) can be a serious problem. If you are asking if you should have a UPS that communicates with your server and does unattended shutdowns, then the answer is probably - but you might get by without one in a home environment with stable power. (but if you are going to plug your server into a UPS, why not take the extra steps to get it to communicate with the UPS?)

 

[William Grzybowski]

What is likely to break is the USB stick...
I personally don't think it is a huge deal for a home nas, just save the config and have a spare usb...

 

[jgreco]

Why is the USB stick likely to break? The root filesystem is normally mounted read-only and the number of writes to /data is supposed to be very limited. ZFS is supposed to be fairly resilient on the storage pool end of things. You definitely don't want brownouts hitting your server, but flipping the power off/on shouldn't be too terrible. A UPS is still a good idea though.

 

[Milhouse]

Even for home use I'd say UPS is a good idea. If you've got a UPS, shutdown control is essential - hoping the power outage doesn't last more than 20 minutes (or whenever the juice from the UPS battery expires) is not a good strategy.

Forget about the USB being the most likely point of failure, there's plenty of other reasons why sudden and unexpected power loss can cause catastrophic failure of hardware and/or data.

In terms of priority however, I'd put a regular backup at #1 (even if it's a bunch of disks in another server you rsync to once a week), with UPS at #2.

Unfortunately however, FreeNAS 8.0.2 out-of-the-box isn't IMHO a suitable candidate for satisfying either of these priorities right now, as rsync can't push data to remote servers (unless you write your own script), and UPS support is buggy with offers of help to improve UPS support going unanswered.

 

[William Grzybowski]

Even for home use I'd say UPS is a good idea. If you've got a UPS, shutdown control is essential - hoping the power outage doesn't last more than 20 minutes (or whenever the juice from the UPS battery expires) is not a good strategy.

Forget about the USB being the most likely point of failure, there's plenty of other reasons why sudden and unexpected power loss can cause catastrophic failure of hardware and/or data.

In terms of priority however, I'd put a regular backup at #1 (even if it's a bunch of disks in another server you rsync to once a week), with UPS at #2.

Unfortunately however, FreeNAS 8.0.2 out-of-the-box isn't IMHO a suitable candidate for satisfying either of these priorities right now, as rsync can't push data to remote servers (unless you write your own script), and UPS support is buggy with offers of help to improve UPS support going unanswered.

haha :) .

 

[leenux_tux]

Is a UPS required ?

Hello folks,

Just wanted to add something to this as I had two problems around a month ago, one I am pretty sure was related to a power outage, the other I can't prove, but it's strange that it happened at the same time....

I should also mention that the two systems i had issues with were plugged in via an extension block that is supposed to have surge protection built in, one of those ones that you can plug your telephone line into as well (plus a bunch of other stuff).

We had a power outage at home and the following happened....

1, Power Supply fried in my CentOS server. Thought the motherboard was shot as well. Luckily I had a spare box that I was just about to dump that I could take the power supply from and put in the CentOS box. I'm pretty sure this was due to the power outage.

2, Memory stick fried in my ESXi server. Now this machine was not even turned on! (but was plugged into the same extension block). I can't prove that the power outage was the culprit but both things happening at the same time ??

I was part way through building my FreeNAS box when all this happened so it was not even plugged in. Would have been interesting to see what could have happened to that though if it was

With this in mind I am looking at installing a UPS as well. I don't trust the "surge protected" extension leads any more.


Nige...

 

[KitDavis]

If you are buying a UPS, pay close attention to the type of battery being used. Most local electrical supply stores carry one or more standard closed cell 12v 6-7AHr batteries that cost about $18. If you get a UPS that uses one or more of these, you can replace the batteries easily every year or so. If you get a UPS that uses an odd or proprietary battery, you may find that it is cheaper to buy a new UPS than ordering a replacement battery. (batteries are heavy and cost a lot to ship).

 

[jgreco]

Try checking with your local low-voltage distributors (security, telecom) for batteries. If you're not a bona fide business, some of them may snub you, but you may find a source to get batteries more cheaply and more quickly.

For SLA batteries, it's very important to check the manufacture dates; do not buy batteries older than maybe six months (Google for SLA and sulfation). Learning to read date codes is a good way to maximize your investment, as is carrying a voltmeter and seeing what voltage the batteries are. For 12V batteries, you're actually wanting to see around 13V IIRC. You do not want a discharged battery (<12V).

Sticking the batteries on a SLA charger to fully charge them, then sticking them on a bench charger at 15V for about an hour as an equalizing charge is highly recommended to extend the life of paired batteries.

Don't forget to take your old batteries to a local recycler to claim several dollars in beer money.