What would happen to the unraid server in a power cut?

[pras1011]

Can someone tell me what would happen?

[jazzysmooth]

I assume you're implying no UPS backup, in which case the machine will shutdown uncleanly.  When power is restored, it will come up and automatically kick off a parity check.  Other than that, it should be business as normal...

 

If there is a UPS, and it is supported by the UPS Powerdown package, then it can be configured to properly shutdown if the UPS battery reaches its threshold.

[Rajahal]

In cases like this (an unclean shutdown), it is somewhat common to see 1 or 2 parity errors.  Generally you can ignore these and be safe, but it is always a good idea to capture a syslog and ask for help on these forums.  If you have more than one or two parity errors then definitely seek help.

[pras1011]

Thanks. I know that with raid, when there is a power cut it's near enough catastrophic. But it doesn't seem that way with unraid. What's a good ups to get for unraid?

[BRiT]

APC.

[Rajahal]

APC brand, USB data connection, removable/replaceable battery, and free shipping are the 4 components of the perfect unRAID UPS.  The size (VA/Wattage) will vary depending on your power needs.

[pras1011]

I am thinking of buying a APC 700 UPS.

 

1) Is this overkill?

2) How do I connect the UPS to the server (excluding the obvious power connections)?

[Rajahal]

1) Depends, what are your server specs?  If you have a kill-a-watt or similar power meter, how much does your server pull from the wall during boot, parity checks, etc?

 

The APC 700 (same model I have, by the way, good choice) supports up to 450W.  Generally speaking that is enough to handle any unRAID server.  Still, you can probably get away with less if you want the UPS to only protect your server.  I like this larger model as I also like to protect my desktop computer, TV, HTPC, etc.

 

2) The UPS will come with an odd cable that looks like a phone cable on one end and a USB cable on the other end.  It is a proprietary cable that only works with APC UPSs (it is not the same as an ethernet to USB cable).  The USB end goes to the server.  The phone jack-looking end goes to the UPS.

[pras1011]

I will be running the Xcase RM420 with 20 HDDs. I only want to protect the server and nothing else. Should I go a smalller model? If so which one?

 

I looked on the back of the APC 700 and I see only a 9 pin connector. Is this the one you are talking about?

[mbryanr]

I am thinking of buying a APC 700 UPS.

 

1) Is this overkill?

What is your server setup? Highly dependent on # of hard drives.

2) How do I connect the UPS to the server (excluding the obvious power connections)?

Assuming you are using the Back UPS model, not the Smart version.

 

1. Connect with the supplied RJ45 - USB cable

2. Installation of the apcupsd package is easiest from unMENU.  It requires a "Clean-Powerdown" package, unraid notify is nice to have to send email notifications. All of these can be installed from unMENU.

http://lime-technology.com/forum/index.php?topic=3688.msg32016#msg32016

 

UPS Topical Index (some of this is old, and not necessary for installation...but lots of information)

 

 

[Rajahal]

I guess we need to clarify which model we are talking about.  The APC BACK-UPS RS BR700G 700VA/450W UPS System is the one I use and it has a USB connection to the server via the port on the back labeled 'data port'.

 

Alternatively, the APC SMART-UPS 700 SU700NET 700VA 450W 120V BATTERY BACK UP UPS looks to me like it uses a 9 pin serial cable.

 

Either should work (assuming your server has both USB and a serial port), but I would recommend the USB model.

 

I believe that either version of the APC 700 is powerful enough to support your 20 drive server, but I won't know for sure unless you can provide measurements of your server's power usage from the wall.

[pras1011]

I was going to get this one: http://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=170460566997&ssPageName=STRK:MEWAX:IT

 

But it doesn't have USB.

 

So I may get one of these ones instead:

 

http://cgi.ebay.co.uk/APC-750-tower-Black-USB-brand-new-batteries-/400173609064?pt=UK_Computing_Networking_SM&hash=item5d2c34b068

 

or

 

http://cgi.ebay.co.uk/APC-1000-UPS-New-style-USB-Guaranteed-New-Batt-/390206923065?pt=UK_Computing_Networking_SM&hash=item5ada252139

 

But these maybe overkill!!

[mbryanr]

I'd recommend the APC Back-UPS 650VA

http://www.scan.co.uk/products/650va-apc-tower-ups-with-internet-dsl-fax-modem-protection-retail-box

 

Edit:

 

I missed that you are running 20 HDD.  I would measure the watts...or estimate using this-

 

http://lime-technology.com/forum/index.php?topic=6695.msg64801#msg64801

 

[Joe L.]

Just be aware...  On older APC UPS, the interface to the server  is via a "serial" cable connected to a 9 pin connector on the UPS.   The cable is NOT a standard serial cable.  It has some pins in the wiring transposed, supposedly to force people to purchase the cable from APC.  Their "proprietary" cable then plugs into a serial port on the unRAID server.  (The "serial" cable may not be supplied if you purchase the UPS refurbished or used)

 

In the same way, on many of the newer UPS supplies by APC there is what looks to be a LAN connector, but upon closer inspection it it not.  It has 10 conductors rather than 8.  This "proprietary" 10 pin connector is cabled to a USB connector on the other end to plug into a USB port on the server.  Again, it is to force you to use their cable.  (It is usually supplied if you purchase the UPS new)  Don't try to plug a LAN cable into the UPS... it won't work and it might damage something.

[Rajahal]

If you don't already have a kill-a-watt or similar, a UPS with an LCD screen is also nice as it will tell you your server's power draw during boot, idle, parity check, etc.

 

Definitely go for a model with a USB connection.

[SSD]

Just wanted to comment on an earlier response in this thread. The number of syc errors can easily be in the hundreds depending on recent write activity to the server. But RFS is pretty robust and typically does not lose data after a hard boot. After the boot unRaid's parity check may be very slow, as behind the scenes the OS is replaying RFS transactions. This can take 15 minutes or more, as it is fighting with the parity check to complete. Let it finish!  After a nasty hard boot like this I always run a second parity check (sometimes just a short while if all the sync errors are at the start of the disk) to make sure all of the sync errors were fixed. (and I have found times when the second check found a few sync errors that hadn't gotten fixed).

 

After having a couple of these scary scenarios occur, I invested in a UPS. No more hard boots when the power flickers!  I consider it mandatory equipment.

[pras1011]

I'd recommend the APC Back-UPS 650VA

http://www.scan.co.uk/products/650va-apc-tower-ups-with-internet-dsl-fax-modem-protection-retail-box

 

Edit:

 

I missed that you are running 20 HDD.  I would measure the watts...or estimate using this-

 

http://lime-technology.com/forum/index.php?topic=6695.msg64801#msg64801

 

 

I used the calculator and it says I need roughly 440 watts! But I think it works on the assumption that all 20 HDD are spinning.

 

Does this one use a propriety usb to rj45 cable? http://cgi.ebay.co.uk/APC-1000-UPS-New-style-USB-Guaranteed-New-Batt-/390206923065?pt=UK_Computing_Networking_SM&hash=item5ada252139

 

Joe L. Your second paragraph seems to be the wrong way round. There is no LAN connector on the back of the this UPS.

 

 

[mbryanr]

 

 

I used the calculator and it says I need roughly 440 watts! But I think it works on the assumption that all 20 HDD are spinning.

Clarification...the UPS must be sized for the peak load as explained by Joe-

 

One issue we face is that in a power-down situation we MUST be able to size the UPS for the peak demand of the server when initially spinning up all its drives at the same time.

 

To shut down the server, all the disks must be cleanly un-mounted. That requires spinning them all up.  The UPS must be able to handle the peak load of spinning the drive up, not just the average load with them all spinning.

 

I have a APC Back-UPS 750VA UPS on my older unRAID server.  It is barely able to handle spinning up the 14 disks mounted in it. (all older non-green disks) It "beeps" telling me it is overloaded for a second or two if I loose power.   It is only able to provide an estimated 7 minutes of run-time.  It is "rated" at a nominal load of 450 Watts and with all its disks spinning during a parity check it is at 53% of its capacity.

Does this one use a propriety usb to rj45 cable? http://cgi.ebay.co.uk/APC-1000-UPS-New-style-USB-Guaranteed-New-Batt-/390206923065?pt=UK_Computing_Networking_SM&hash=item5ada252139

 

It uses a prorietary usb cable

USB Available SmartSlot™ Interface

 

and a propietary RS-232 serial cable (cannot be used simultaneously)

http://www.apcmedia.com/salestools/ASTE-6Z8LFV_R1_EN.pdf

 

Edit:  Some of the Back-UPS models have the proprietary LAN/USB connection.

 

[pras1011]

Hi Mbryanr,

 

If you look at page 3 of the manual it gives warnings about using a different serial cable than the one that is supplied but there are no warnings about the USB cable. This leads me to believe the USB side is not propriety.

[prostuff1]

Hi Mbryanr,

 

If you look at page 3 of the manual it gives warnings about using a different serial cable than the one that is supplied but there are no warnings about the USB cable. This leads me to believe the USB side is not propriety.

 

On the UPS's I have both connect with a Ethernet-Like connection from the UPS side to a standard USB connection on the other.  I know this cable is proprietary, not sure about the others though.

[mbryanr]

Hi Mbryanr,

 

If you look at page 3 of the manual it gives warnings about using a different serial cable than the one that is supplied but there are no warnings about the USB cable. This leads me to believe the USB side is not propriety.

 

On the UPS's I have both connect with a Ethernet-Like connection from the UPS side to a standard USB connection on the other.  I know this cable is proprietary, not sure about the others though.

 

This model has a Type B USB port to Type A USB cable.  

 

Who knows what they did with the internal connections...I wouldn't experiment.

 

It may not be proprietary, but they have this warning though:

Use only interface kits supplied or approved by APC.

 

and since the cable is included...easy decision.

[pras1011]

I wouldn't mess with the serial connector but I would test the USB connector by using a non-APC USB and then plugging this into my laptop/PC.

 

[Eisi2005]

Hi,

 

could i use one of this items ?

 

APC BR550GI or

APC BK650EI or

APC Back-UPS CS 650

 

In Germany i could not find the APC BACK-UPS RS BR700G. I think the APC Back-UPS CS 650 is good for me. 400 W are enough for me with 7 hdd and USB is available

 

Greets

Eisi

 

 

[Rajahal]

The last two look like the same model with a different name.  Any of them should work.  I agree that 400W should be plenty for a 7 drive server.  I run my 9 drive server off a 350W.

[PeterB]

I think the APC Back-UPS CS 650 is good for me.

 

This is the model I'm using - it supports my unRAID server (currently only five drives), plus a desktop machine together with its 22" LED/LCD display.