Conference aosg::lsm

751.0. "rootvol problems and questions" by HYDRA::BRYANT () Thu Feb 06 1997 13:30

Hello,
I have a partner who is getting an advfs "Next free page has no free mcell"
error after attempting to restore (using his own app) to the rootvol.  Here is
mail from him describing what he believes his problem stems from.  He also has a
couple of questions related to rootvol.  I'd appreciate any feedback.
Thanks.
Pat Bryant
Software Partner Engineering
-----------------------------------------------------------------------
We have a system backup/restore product which we want to support LSM.
The product lets users backup/restore raw disks and in the case of LSM
we backup/restore LSM raw files (e.g. /dev/rvol/rootdg/rootvol) to/from
tapes.  My questions involve a disaster scenario in which an LSM
bootable disk (assume no mirroring exists unfortunately) crashed and 
we need to restore the system back from the tapes.  There are two 
typical ways for people to perform disaster recovery:

1. Reformat the crashed disk and install OS and LSM to it, then perform
   recovery tasks.

   I tried this method to restore my original /dev/rvol/rootdg/rootvol
   back. However, my files were not restored even though our product could 
   successfully write() the data from tape to /dev/rvol/rootdg/rootvol.
   My question is, does LSM allow such writes to the rootvol while
   it is mounted to / file system?

   p.s. my rootvol was encapsulated from AdvFS so I have a link:
        /etc/fdmns/root_domain/rootvol ---> /dev/vol/rootdg/rootvol

2. Install OS on another disk and restore data to the original disk.

   Is it possible to use this method to restore the LSM rootvol?
   The rootvol has the "root" usage-type.  Does LSM allow you to create
   a volume with "root" type?  I tried to do this using volassist
   utility to create a volume on the original disk, and unfortunately
   it core dumped.