Quoting Thomas Schmitt (2015-01-30 14:25:50) > Hi, > > Justus Winter wrote: > > 3. Remaster using `grub-mkrescue --output=my-bootshell.iso /=master'. > > The beauty of grub-mkrescue.
Yes, it's super nice :) > > To start an translator on demand, the file system needs to support > > storing a passive translator record somewhere. > > [...] I don't know if it would be possible to store it on a cd. > > At what time would it have to be written ? > If it's when the ISO is produced, then one just would have > to negociate a suitable representation between xorriso and > Hurd. Production time. > If it needs write capability at mount time, then it depends > on the medium type. It would also break the model of a > read-only filesystem. It does not. > > > I read https://www.debian.org/ports/hurd/hurd-doc-translator > > Can you be more precise, e.g. cite the paragraph in question? > > I mean the "underlying inode the translator is attached to", > which gets introduced in #concept, demonstrated as mount point > in #examples, and referred to in #actpas: > "[...] the first time the passive translator is accessed, > it is automatically read out of the inode and an active > translator is started on top of it using the command line > that was stored in the inode." > > Is this inode the mount point directory inode in the > parent filesystem (e.g. in ext2) or is it the root directory > of the ISO filesystem ? The former. Though it doesn't need to be a directory node. On the CD, /run is a simple empty file. > (Or does each inode of the ISO get attached a translator ?) No. > > ext2fs stores the > > record in the operating system specific part of the ext2 ondisk > > format. That is undesireable for ext2. > > Well, the System Area of ISO 9660 is playground of GRUB2 in > this case. So it would be unwise to use it for translator > info without coordination with GRUB2. > > The System Use Area of the "." Directory Record in the > extent of the ISO 9660 root directory would be a fine > place for extra info. That's were SUSP and Rock Ridge info > gets stored. > One could define a new SUSP field for Hurd translators > or use my AAIP extension, which i use to store Linux-ish > xattr and ACL. > http://libburnia-project.org/wiki/AAIP > In the latter case one would define one or more variable > names in name space "isofs" or "system". (Depends on how > close one wants to stay with Linux xattr habits.) > > > Well, the overall question is: Is it worth an effort ? > I.e. can the ISO stay read-only and does a passive translator > provide advantages ? I guess it could. Then we wouldn't need to make /dev a tmpfs and create it's content on demand. Then again, doing so is easy enough (with the bootshell). :) Justus
