It definitely wasn't working on the 44 until I plugged it into the 24. Is it reasonable that the 24 formatted the drive for 2TB, which allowed the 44 to recognize it, realize it had more capacity, and reformat the drive for 3TB? When the 44 finished the reboot, it showed the start-up messages you see with a new drive or new software.
At this point, I have 3TB on the 44 and 2TB on the 24. I could switch the 3TB back to the 24 as an experiment, and then read the partitions off a PC to see if it's formatted for 2 or 3TB. But everything is working, and my experience with eSATAs tells me to leave well enough alone.
Well, curiosity, plus the possibility of adding at least 1TB more storage to the HR24, got the best of me.
Conclusion: The 24 does indeed support an external drive larger than 2TB.
Connected WD30EZRX 3TB drive to HR24-100. Thermaltake Blacx dock. The drive had been successfully connected to an HR44-500. See previous posts in this thread.
HR24 displayed the "formatting external drive" notice.
Confirmed connection through External Drive test on Guided Tests menu.
Connected the WD30 to a PC.
Control Panel/Device Manager/Disk Drives/WD30
Properties box/Volumes tab/Populate volumes:
Partition Style: GUID Partition Table (GPT)
I surmise from these stats that the drive was formatted by the HR24 for 2.83TB of recording space, with 28.6GB for DirecTV housekeeping space.
Reconnected the WD20EVDS 2TB drive to the HR24, where had been successfully connected prior to this test.
No "formatting drive" displayed. Guided test showed external drive successfully connected. Test recording placed on drive before the test still in playlist.
Reconnected the 3TB drive to the HR44.
After I entered diagnostic mode for the guided test, the "formatting storage device" message appeared. Guided test confirmed presence of 3TB external drive. Of couse, no recordings on the local playlist.
So it appears that the 24 supports at least a 3TB external drive.
Remaining questions: Although it formats the drive to capacity, will it actually record past 2TB?
Why does the 24 reformat a drive already formatted? Do the 24/44 not recognize each other as compatible devices? We know from past attempts that recordings on one HR2x will still show on the playlst when the drive is connected to a different HR2x (although the recordings will not play).
Looking forward to comments on this.