-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA512 On 07/14/2014 01:11 PM, Rod Smith wrote: >> How is this at all related? Windows already ignores 0x83. > > It does with the default set of drivers. What if somebody loads a > Linux filesystem driver, though? I don't happen to know what > actually happens in this case, but that's (partly) the point: When > you set inaccurate data, you can't predict what will happen with > some random tool with which you're unfamiliar.
That is a possible ( though unlikely and easily fixed and knowable by such a future hypothetical program ) problem with 0x83, but not 0xFD since that already means "raid, not normal filesystem". > * Non-kernel tools might care about the type code. In fact, Chris > quoted the mdadm man page earlier in this thread, and it explicitly > states that it DOES care about the type code! Only in the one special case of the deprecated auto assembly feature. > * Other OSes do check the type code, and if some non-Linux driver > or utility behaves in a particular way based on the type code, > setting something inappropriate invites problems that we can't > predict. They only use it as a binary "mine" or "not mine", and treat 0x83 and 0xFD, and 0xDA the same. > That's not what the modern version of mdadm wants, though. It doesn't "want" anything. It is quite happy with any type code, or not even having a partition table at all. > In an ideal world, of course, the mdadm developers wouldn't have > changed their tools' expectations from 0.9 to 1.0; but they did, > and that means that the tools that actually set the partition type > codes must adapt. Again, the tools don't know or care about the type code. > All that said, there is a further complication, and this one isn't > parted's fault: The 0xDA type code that's suggested by the mdadm > man page is NOT specific to Linux RAID. According to > http://www.win.tue.nl/~aeb/partitions/partition_types-1.html, it > refers to "non-FS data"; and according to > https://en.wikipedia.org/wiki/Partition_type, it can be that or a > Powercopy backup. There may be other specific tools that use it, > too. Thus, I'd be a little wary of just switching 0xFD to 0xDA as > the MBR RAID flag in parted. IMHO, what's needed is some > coordination between mdadm, parted, fdisk, and gdisk authors to > settle on a standard for this. That's another good reason against it. -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iQEcBAEBCgAGBQJTxxleAAoJEI5FoCIzSKrwYsAH/2c5zPxITX/SS35coII5kzWw pE4a2SxDdn9fS+JIXCly2GWzWeGCznJpXBEkMMoYoicMzoVDBGZ8TzV+QM4nD2/u PtlONGFD8MpkG3PknnCYNqIVJFra3ZnA63aF0E1i77PTFt6mlu5dNkxLLk8NF4QM 2XoQCt/HkS/VkvFqmdLcqu7Adh/NHma1n4/jiQHrcTdlzu2iFgXP7qKWf/NFX8lh 0LhU/9AKw1g3dIRAAIvjUwMPL0/Jg6eyzfbNTyuw5wYdnepyBfMvYnz0hCAVq92V A4Cd0mWCb9VNyc0qQrgBOpoSiabviepnpq054K5MYJIbAN6UcuZnYEng/Z+3ZrA= =78ZZ -----END PGP SIGNATURE-----
