RE: The old raw devices chestnut.

Oracle uses some offset when it placed data onto raw devices. When You restore data previously kept on cooked files onto raw devices, You need to copy files using this offset (smth like 500 kBytes on Digital UNIX, may very on other platforms) ------------------------------------------ Alexey Sonkin > > Any of Oracle, Informix or DB2 will cope with this equally as well as if on > "cooked" disk. Informix will even let you restore a dbspace held oncooked > chunks to be restored to a raw disk (or vice versa). The others may do too > although I think there is more fannying around needed. > sending to informix-list

Alexey Sonkin wrote: > Oracle uses some offset when it placed data onto raw devices. > When You restore data previously kept on cooked files onto > raw devices, You need to copy files using this offset (smth like 500 > kBytes on Digital UNIX, may very on other platforms) I think you might be pointing to a bit of ancient history (I hope it's ancient history on all modern UNIX) Time was, the partition table, or information about each partition was stored in the first few sectors of the disk or partition on some UNIX. This was not an issue with filesystems of course, because the local O/S utilities took care of building them in just the right place with just the right size. I can't think of any contempory UNIX (that I've used recently;-) which does something this crude, although if you try to attach your raw spaces to the very low level device names (the device names which address actual ferrite particles) then you would probably run into this issue. Using names from the logical volume manager is definitely the way to go.