🚀 go-pugleaf

I have an RT 6150 with two 70E hard disks.  I am running AOS 4.3.
Since it is for me a new computer, I initially was only using the
first hard disk (hd0).  Once I had mastered essential stuff (like
making backups), I moved on to the creation of a new file systems on
the second hard disk (hd1).

Since I am mostly teaching myself Unix system administration with
the help of a few good books, I have been prone to trial and error
experimentation.  During this experimentation, the contents of the
filesystem stored on hd1g mysteriously dissapeared.  Also, I kept
getting an fsck error message I had trouble deciphering that read:

      SUMMARY INFORMATION BAD (SALVAGED)

I suspect the cause of my trouble was due to the fact that I
partioned hd1 into sizes that were both non-standard and
different from the partions sizes of hd0.

I used the minidisk command to set up the first disk as a standard
root drive.  hd0a is root, hd0b is swap space, hd0g holds /usr.

I set up the second disk with standard root partitions also, but
then deleted and re-created hd1b and hd1g, so I could create a
larger hd1g.  I have used hd1a for a dd backup of hd0a.  I also
found out by trial and error that hd1b had to be a swap partition
if I ever wanted to boot from hd1 (if I ever need to repair hd0a).

        standard root
        delete hd1b
        delete hd1g
        create hd1b 32743 11025 swap
        create hd1g 32744 97735 00


                                        512 Byte Blocks
                                        ---------------
    hd0 standard root   name    iodn    size    start   type
                        ------  ------  ------  ------- ------
                        boot    32736      105    140   ipl
                        hd0a    32737    32585    245   00
                        hd0b    32738    33565  32830   swap
                        hd0g    32739    75195  66395   00

   hd1  customized      name    iodn    size    start   type
                        ------  ------  ------  ------- ------
                        boot    32741      105    140   ipl
                        hd1a    32742    32585    245   00
                        hd1b    32743    11025  32830   swap
                        hd1g    32744    97735  43855   00


The above partition structure for hd1 did not work properly.
It appears that some parts of the Unix software recognize the sizes
of the partitions, whereas other parts (perhaps the swapper daemon)
thought that both disks were partitioned the same.  Whatever the
cause, however, what happened is that all the subdirectories and
files on hd1g were mysteriously deleted at some point from one day
to the next.  I cannot rule out human error, but it seems most
likely that the swapper daemon was at fault.  Hardware diagnostics
were run by an IBM service rep, but no defects were found.

hd1 was therefore re-partitioned to the standard root configuration.
Both hard drives now have exactly the same partition sizes.
So far, so good.  No data has been lost from hd1g since the
re-partitioning.

So, does anybody have any suggestion/advice to offer?  Should I have
trusted the author of one of my books who warned me to set up both
my disks the same?  If so, why is there a "standard source" option
under minidisk?  Does the very existence of hd1b cause the system
to want to use it for swap space, and if so, does the swapper assume
that hd0b and hd1b are the same size?  Did my use of dd cause any
problems?

Sorry for the length of my query.  Hope the feedback I get will be
educational for the newsgroup.  Thanks.

-- Richard Anderson                 cn.rna@forsythe.stanford.edu
   Systems Department, Green Library
   Stanford, CA 94305-6004               (415) 725-7932