On Sat, Jun 27, 2015 at 08:52:19PM +0200, tlaro...@polynum.com wrote: > > [Trying to use an UDF formatted USB disk between NetBSD and Windows] > > On Sat, Jun 27, 2015 at 07:13:04PM +0200, Benny Siegert wrote: > > [...] > > > when using newfs_udf(8) while the Windows formatted shows the first > > > pseudo partition as a 238 aka "GPT Protective MBR". > > > > So the stick has a GPT partition table, not an MBR. You will want to > > use gpt(8) to create one. (I would be interested in knowing which GPT > > partition type Windows uses for the GPT partition.) Something like > > > > gpt create sd0 > > gpt add -t windows sd0 > > > > I have created a gpt: still not recognized on Windows. > > Then, under Windows, I have formatted by specifying "/A:512" (not > documented in help) to create an UDF with 512 allocation blocks. > > Then under NetBSD, gpt (gpt show -l sd0) gives: > > start size index contents > 0 1 PMBR > 1 1 Pri GPT header > 2 32 Pri GPT table > 34 2014 > 2048 1953454080 1 GPT part - "Basic data partition" > 1953456128 2015 > 1953458143 32 Sec GPT table > 1953458175 1 Sec GPT header > > The problem is now, I imagine, to create a "wedge" so that the UDF is > not searched at the very beginning but at block 2048. > > But dkctl(8) doesn't help a lot: addwedge gives systematically "invalid > argument", without information, and, furthermore, udf is not listed as > a valid ptype (is cd9660 instead OK?).
Oups! The dk0 was already created (message on console) so adding the same partition failed. Mounting /dev/dk0 then with mount_ufs(8) now succeeds. I suspect that doing it from NetBSD should work too : 1) Create a GPT header on the USB disk; 2) Create an uniq partition on the remaining space after first 2048 blocks and before duplicate info at end with "unused" type ("Basic data partition"?); 3) Then whether after deconnecting and reconnecting for the automatic creation of the wedge, or by adding the wedge with dkctl(8), format the partition with newfs_udf(8). Seems solved (but I will have to verify that what I write on NetBSD, using for safety "mount_udf -c" to "close" the sessions, I will be able to read the result under another OS. Thanks! -- Thierry Laronde <tlaronde +AT+ polynum +dot+ com> http://www.kergis.com/ http://www.arts-po.fr/ Key fingerprint = 0FF7 E906 FBAF FE95 FD89 250D 52B1 AE95 6006 F40C