Re: kernel work week of 3-Feb-2010 HEADS UP

[Matthew Dillon <dillon@xxxxxxxxxxxxxxxxxxxx>]

:Btw, that should be already possible using multiple HAMMER volumes.
:The SSD partition should be made the root volume. It can be very
:small, so that only the UNDO log fits on it (maybe a GB?), the second volume
:would then be the regular hard disk. Maybe we'd need to give newfs_hammer
:a specific option so that it treats all space of the first volume as UNDO
:and
:uses the second volume for storage.
:
:I think I can implement that. Matt, do you think the option to newfs_hammer
:is
:a good idea?
:
:Regards,
:
:  Michael

    Not for newfs_hammer.  It would be a good fit for the hammer
    volume-add directive, though.

    You could add a feature where it adds the volume and moves the
    UNDO FIFO into it.  volume-del might also have to be adjusted to
    move the UNDO FIFO back out (I don't recall offhand if it moves
    UNDO blocks).

    I have to say though that I am a bit on fence.  I don't like the
    idea of the filesystem becoming non-operational if you pull the
    SSD, which is what would happen.

						-Matt