Connecting an Uninterruptable Power Supply to my recorder

[Mack46]

This is my second attempt at posting this because I got an error on Submitting the first one so if it appears twice then maybe the moderators can delete one.

My PVR is a Beyonwiz V2.

A good way to corrupt hard drive is to have a power failure while writing to it. For this reason I am considering connecting a UPS and I will appreciate any assistance from anyone who has had experience with this.

In particular, I would like to know if the software that accompanies the UPS can be installed so that it automatically stops the recording and safely shuts the recorder down. If so, some guidelines on the installation will be most appreciated.

[peteru]

You didn't say which UPS you are considering, but unless the UPS in question comes with software that includes Linux source code, it is unlikely to work with the V2.

It may be possible to use the V2 SDK to build some third party open source software, such as Network UPS Tools or apcupsd and use that...

[Mack46]

To peteru,

Thanks for the reply. At this stage I don't know which UPS. I guess that I was hoping that someone had previous experience with connecting one and if so, I would be guided by their experience. I have a Cyber Power UPS on my desktop computer.

I am sure that most UPS's will work without the auto shutdown software installed. AFAIK they have an audible alarm if the power fails and keep the recorder running for a while until the user can shut it down. However, it the user is not available at the time then that is not much help because the UPS will run out of power and the recorder still eventually shuts down through loss of power.

Personally I don't have the technical knowhow to create the required software but perhaps the Beyonwiz manufactures can look into what is required to operate the auto shutdown. I should think that other users would be interested.

[peteru]

The V2 does not draw much power. A typical UPS intended for use with a desktop computer is likely to keep the V2 powered all night. That may be long enough to not worry about shutting down.

Also, by default the V2 uses the ext4 file system on it's drives. It is a fairly robust file system with journaling and it is less prone to corruption than FAT32. Most modern drives are also designed to not corrupt data on power loss.

The firmware is held in flash memory and also unlikely to suffer major corruption due to sudden power loss.

Sudden loss of power is most likely to lead to loss of the files being written at the time, which is most likely the current recording or the timeshift buffer. That may be an acceptable risk factor.

There are other reasons to deploy a UPS, including power conditioning, brown-out protection and surge protection. None of those features require any software to be installed on the equipment being protected.

In summary, pick a UPS based on how well the electronics in it will protect your equipment and don't worry about the software aspects. Prefer UPS units that can provide long run times when used with equipment that draws small amounts of current.

[exitguy]

A good way to corrupt hard drive is to have a power failure while writing to it. For this reason I am considering connecting a UPS and I will appreciate any assistance from anyone who has had experience with this.

No point, as soon as you lose power everything stops. Modern drives do not corrupt with power failure, especially in a PVR. Never had an issue with either HDD in Topfield TFR-7160 or SSD in Beyonwiz T2, and they have been through a few "brownouts" as well as "failures" over the years, with the last as recently as a week ago during the storms here in Mel.

[prl]

Modern drives do not corrupt with power failure, especially in a PVR. Never had an issue with either HDD in Topfield TFR-7160 or SSD in Beyonwiz T2, and they have been through a few "brownouts" as well as "failures" over the years, with the last as recently as a week ago during the storms here in Mel.

The kind of corruption being talked about here is filesystem corruption, not hardware block-level corruption.

It's true that modern U*ix filesystems are more resistant to corruption on power failure or "pull the USB plug" than they used to be.

The setup for the default ext4 filesystem mounts on the T/U/V Beyonwizes is for the journalling parameter to be set to "ordered". This journals only file system metadata, not filesystem data, but it ensures that file data is written before the corresponding metadata is committed to the journal. This gives file system consistency to new file write and appends to existing files, but not when a file is being re-written (details here).

Since recordings are made as new files, the individual files are probably going to be in a consistent state after a power outage. However, because some recording metadata files are written at different times, or their application buffers may be written at different times from the main recordings, metadata files for a recording being made at the time of an outage may not be consistent with the data in the main recording data file.

[IanL-S]

Not sure if it is just bad luck on my part, but I have found that CyberPower UPS go troppo - the alarm goes off - if the attached device has modest power requirements. Or worse, it refuses to allow current to pass to the attached devices. I found this with my Synology NAS (also had router and switch attached).

Ian

[exitguy]

Not sure if it is just bad luck on my part, but I have found that CyberPower UPS go troppo - the alarm goes off - if the attached device has modest power requirements. Or worse, it refuses to allow current to pass to the attached devices. I found this with my Synology NAS (also had router and switch attached).

Ian

Have been using a CyberPower UPS for over 10 years and never had any issues. It is out in the open with plenty of ventilation, does not get hot and has heaps attached either directly or via a powerboard, all up 7 devices
Direct - Arris CM8200B, Ubiquiti Edgerouter X, 6 Plug Powerboard (all 3 on the Battery backup plugs)
Powerboard - Desktop, Monitor, Synology NAS, Creative Speakers, TP-Link 8 Port Gigabit Switch

[IanL-S]

I am glad someone is able to get it to work. It worked for me for many years, then the battery died (not user replaceable); tried 3 different models, new out of the carton and they refused to pass current either through the UPS or the surge protection ports. I suspect there is a serious bug in the firmware.