I know, i know, i jumped the gun on upgrading.
Submitted diagnostics when it was happening a couple of days ago ( cf4a54bb-d9f8-461b-9e68-805c1dd87c32 ), but I'm leaning towards my external disk being overloaded - I'm wondering if the exFAT i brought over when i was using the pi image might not be best placed.
It struggled again last night, though not as badly, when recording multiples at once, though i easily used to do this on the pi, which much less horsepower. Something is up...
Just for the record, I am not experiencing anything like that. Channels and all the media are on an a Thunderbolt 3 (USB3.1) connected external disk formatted in OS Extended. Wouldn't think that the exFAT would make any difference as I don't think the demands are that high on the disk. But who knows? That is the only difference I see off hand.
Some other info if it helps to narrow things down:
Mac: M1 Mac mini (base version) running headless. 1GE connected to the same switch as HDHR5-4K. Nothing else running on the Mac except Apple Music, a small server (iTunes-api) and TimeMachine for backup.
Channels: DVR 2021.10.25.1801 with TVE (Spectrum), Pluto, STIRR, and 15 virtual channels in addition to the HDHomerun. 8 clients (all ATV with a mix of HD and 4K)
Happy to help if I can, if there is something amiss with Monterey, I would certainly want to understand. My only other thought is if you have a new install, sometimes spotlight will chew up a lot of resources as it builds its indexes over the first couple of days.
I'm on USB3 (via the USB-A port) to this drive
Also a headless M1 mini base version. What was weird is that the buffering was on an HDHR prime source, which should be reasonably easy:
2021/10/26 21:19:23.439378 [DVR] Recording for job 1635292790-45 from 131B163D ch792 into "TV/The Bachelorette/The Bachelorette S18E02 2021-10-26-1959.mpg" for 42m37.254307s
2021/10/26 21:19:55.378390 [WRN] Buffer for 131B163D ch792 is more than 50% full (clients=1, len=33555180)
2021/10/26 21:20:09.946920 [WRN] Buffer for 131B163D ch792 is more than 75% full (clients=1, len=50332040)
2021/10/26 21:20:32.041859 [WRN] Buffer for 131B163D ch792 is more than 95% full (clients=1, len=63753820)
2021/10/26 21:20:34.373775 [WRN] Buffer for 131B163D ch792 is more than 99% full (clients=1, len=66438760)
2021/10/26 21:21:44.666474 [WRN] Buffer for 131B163D ch792 is more than 50% full (clients=1, len=33555180)
2021/10/26 21:22:01.138761 [WRN] Buffer for 131B163D ch792 is more than 75% full (clients=1, len=50332040)
2021/10/26 21:22:12.794169 [WRN] Buffer for 131B163D ch792 is more than 95% full (clients=1, len=63753820)
2021/10/26 21:22:15.125813 [WRN] Buffer for 131B163D ch792 is more than 99% full (clients=1, len=66438760)
2021/10/26 21:22:27.038368 [WRN] Buffer for 131B163D ch792 is more than 50% full (clients=1, len=33555328)
2021/10/26 21:22:45.325783 [WRN] Buffer for 131B163D ch792 is more than 50% full (clients=1, len=33555364)
2021/10/26 21:23:03.156796 [WRN] Buffer for 131B163D ch792 is more than 50% full (clients=1, len=33555180)
2021/10/26 21:23:24.223485 [WRN] Buffer for 131B163D ch792 is more than 50% full (clients=1, len=33555180)
2021/10/26 21:23:39.727889 [WRN] Buffer for 131B163D ch792 is more than 50% full (clients=1, len=33555180)
2021/10/26 21:23:54.295278 [WRN] Buffer for 131B163D ch792 is more than 75% full (clients=1, len=50332040)
2021/10/26 21:24:06.579675 [WRN] Buffer for 131B163D ch792 is more than 50% full (clients=1, len=33555180)
2021/10/26 21:24:43.335582 [WRN] Buffer for 131B163D ch792 is more than 50% full (clients=1, len=33555180)
2021/10/26 21:24:57.904408 [WRN] Buffer for 131B163D ch792 is more than 75% full (clients=1, len=50332040)
2021/10/26 21:25:14.318252 [WRN] Buffer for 131B163D ch792 is more than 95% full (clients=1, len=63753820)
2021/10/26 21:25:16.649553 [WRN] Buffer for 131B163D ch792 is more than 99% full (clients=1, len=66438760)
Very odd. Is there something in the client or server settings that could be causing it to transcode?
I don't see anything in my logs re: buffering for any source either before or after the upgrade. Buffering should be a non-issue for HDHR source anyway.
The smart guys will be online soon and I am sure they can make better sense of it all. That and more suckers like us taking the Monterey plunge will provide more and better data to troubleshoot.
Yeah. I may invest in a USB-C to B mini weirdo cable, on a lark (can't hurt to have one around, anyway).
Those buffer errors look to indicate an IO bandwidth issue. You may be right that it's due to your external drive being exFAT; I'm not sure about the quality of Apple's exFAT driver.
yeah - I hope both our hunches are wrong, as moving everything off / format / back on is a major PITA.
It could also be a signal that something may be deteriorating with your drive ... check its SMART status, and maybe give it a look in Disk First Aid.
SMART is clean. Ran both the MacOS disk utility check and the WDC utilities checks - no errors anywhere.
Black Magic speed test seems in spec, too.
Again, just for reference, I scored in the 190's on both Read and Write with Black Magic. I don't know that the difference is significant, but I would think that your Read speeds would be at least equivalent if not higher than Write.
That said, not sure why disk access is even that important when just passing through a stream from HDHR. Tuner sharing maybe? But I have that turned on in my rig without issue.
I wish I could be of more assistance, but at least I am helping keep the topic bumped to the top 
Yep - I'm with you - FWIW that static image wasn't totally representative - it's more equal when running.
The minute i see "Buffering" errors it's usually something for the devs, but let's see.
I did snag a USB-C/TB to B micro weirdo cable, so let's see if changing the bus helps at all.
One more data point to keep in mind: it looks like those are possibly MPEG2 streams from a Prime, which usually are higher bandwidth than an internet stream. There may also be a network bandwidth issue at play, too; meaning, the Mac cannot send out the packets as quickly as they're coming. Generally this is a drive/IO issue, but the network aspect may be something else you want to troubleshoot, too.
Just remembered I have the exact same drive as yours attached to my local machine over standard USB. It is formatted MacOS Extended. Black Magic for Write/Read in this drive was ~ 160/175, respectively.
So, even if this doesn't turn out to be the issue, may be worth looking to get off of ExFAT in the long run to eek out a bit more performance on the drive.
I haven't run a check in a while, but the ATV i was watching, the HDHR, and the MacMini are all CAT5e hardwired. I'd be floored if this were strictly bandwidth.
It's also a 720p maybe 10Mb/s on a good day cable feed - not even a full bore 1080i one.
I'll run a check later on and report anything that looks off, but have my doubts.
Hmmmm - USB problems with Monterey, you don't say?
I'm not saying this necessarily, or even likely, in play, but it sure is interesting.
Something fishy is going on here!
Switched to USB-C - let see if behavior changes.
Also - one other thing that is absolutely in play - spotlight search. I won't ever search using it, and it's absolutely going to be a pig I/O-wise, so I prevented it from looking at the external USB drive.
I would almost suggest that @tmm1 and co add this to suggestions for MacOS install, at least for external drives. SSD's maybe too, but for different reasons.
My load values have dropped fairly substantially after disabling MacOS's spotlight search from looking at the DVR drive. I had never seen load values below 1 on the mini - now it's commonplace.
Clean since disabling spotlight search.
Anything from my buffering diagnostics? Want to make sure I'm not shooting in dark here...
Cough - this thing on?
