Hard Drives & DVRs: Filesystems

This is the second post in the series on hard drive selection for DVRs. The first post talked a bit about the type of workload that a DVR imposes on the drives and went through some basic ways of measuring raw drive performance.

In this post we’ll take a look at the impact that the filesystem has on I/O performance, again with an emphasis on a DVR recording and playback workload. The filesystem is one of a few system components that we have some control over and that has a great impact on how the drive behaves.  The I/O scheduler is another component that we’ll take a look at in a subsequent post. Continue reading “Hard Drives & DVRs: Filesystems”

Hard Drive Selection for DVRs

This and the next few posts will be focusing on hard drive selection for DVRs. This post will look at the type of workload that a DVR imposes on drives, using Project Entangle as an example. Subsequent posts will look at various system characteristics that can affect performance and performance measurements from some drives. And we’ll take a special look at shingled magnetic recording (SMR) drives, as they tend to have some very peculiar performance characteristics.

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Do You Need a VHF Antenna?

I’ve been in Las Vegas this week for the Amazon re:Invent conference. While there are enough sessions, receptions, and parties to keep you occupied day and night, I just couldn’t pass up a chance to check out the Las Vegas OTA airwaves. The Vdara staff was a bit mystified by my request for the highest south-facing room I could get, but very accommodating. So here I am on the 49th floor with good line-of-sight to the major towers (and a view of the desert instead of the Bellagio fountains, which apparently most people ask for.)

I had packed up a full Entangle development setup, including my trusty Silver Sensor antenna (aka the Zenith ZHDTV1). What I failed to do while busily packing was to check the RF frequencies of the Las Vegas broadcasts. As it turns out there are a few major channels in the VHF bands, including one on channel 2. Sadly the Silver Sensor is a UHF-only antenna.

This brings up an interesting point regarding the current state of OTA antennas: many of them, particularly the compact ones, are UHF-only. Even the ones that claim to be both UHF and VHF don’t handle VHF very well. At best they’ll pull in VHF-Hi. But can you make do with a UHF-only setup?

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Using SSDs in DVRs

Every so often someone asks if I’d use an SSD to store recordings in a DVR. Just a few years ago, I would have quickly replied “No.”  SSD endurance just wasn’t up the demands of recording TV broadcasts.

But the last few years have seen some advances in the durability of SSDs. Now rather than “No”, the answer is “It depends…”

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