I have an App on my iPad called iTelnet. I use it to boot into HDR mode and have been using it to enter the commands which you have been supplying.You've lost me there!
It sounds like your external disc has sector errors. I assume the Humax HD has a format command to setup an external disc to start with. Try formatting the disc with a windows system FAT32 or NTFS, doing a surface scan afterwards. Once it can be read by the Windows system connect it back to the HD and it should reformat it to ext2 or ext3 on its own.If only I could remember where I put that GParted disc!
Are you using a powered external hard drive, or a usb-powered drive? It may be that the disk is drawing too much current for the Hummy to source, leading to the problems. This would lead to intermittent failures but it could appear to work absolutely fine on some other systems.The Humax formatting command gets no further than renaming, then it quits with a error message.
I have a notion that the problem is to do with the Custom Firmware install but I can't reinstall until the disk becomes writable again.
The Humax can see the HDD as a read only disk and can play all the recordings on there.
Thanks for your interest. If all else fails...
I have found the instructions that came the drive giving instructions on how to obtain an online manual. I will give that a look first to see if there is anything useful there.