[mythtv-users] Wiki: Balanced Disk I/O

[Peter Bennett (cats22)]

Hi MythTV experts

I am updating the wiki and wondering about the Balanced Disk I/O setting.

https://www.mythtv.org/wiki/Storage_Groups#Balanced_Disk_I.2FO

The above page recommends if you are doing more than 2 recordings at
once to use this setting to get recordings put on separate file systems
to avoid buffer overruns. I am thinking of changing that recommendation.

A quick back of the envelope calculation tells me that I could record
some 50 HD programs at the same time on one disk drive, based on 1
Gb/sec transfer rate and 8 GB per hour on each HD recording.

Clearly 50 at a time is theoretical and unlikely because it would be
affected by seek times. However HD programs vary from 3 GB to 8 GB per
hour which means even more than 50 at the same time.  Also drives are
rated at 6 Gb/sec which means 300 HD recordings at the same time(!).

You could surely record at least 10 HD programs at the same time or
maybe many more, so unless you have a very unusual situation it seems
that you need not concern yourself about hard disk performance.

I have 6 tuners and have never had a disk performance problem, even
while watching at the same time as recording, but I have probably not
recorded 6 channels at once.

Does anybody have an opinion on this?

Peter
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