[cs615asa] HW2

[Jan Schaumann]

Hello,

I've just sent out grades for HW2.  If you have not received an email
with your grade, please contact me ASAP.

A few common notes:


I asked you to submit the transcript with timestamps.  If you haven't
figured it out yourself by now, you can replay these transcripts to view
exactly how the session was executed.  For example, given the files
'timestamps' and 'typescript', you can run a (somewhat sped up) replay of
the session via

scriptreplay -d 10 -t timestamps typescript

Reviewing the sessions, I notice that many of you appear to not pay
attention to the output of the commands.  When error messages are
encountered, please do read them, as they usually tell you exactly what
the problem ist.


Some of you misunderstood that the assignment was to be done on multiple
operating systems, or that different distributions of Linux are in fact
versions of the same operating system.  GNU/Linux comes in a variety of
flavors, but still are the same OS.  As such, the differences between
them are minimal (compared to the differences between a Linux version
and one of the other OSes we consider).


Many of you also did not consider (in depth or at all) using a volume
across different OSes.  As different OSes have support for different
filesystems, one may need to use different options in order to make this
happen, but for all the OS mappings we are considering, it is possible
to find a solution.  Trying just the default and then giving up when an
error is encountered is not sufficient when as a SysAdmin you have to
make things work.


When using NetBSD or FreeBSD, some of you neglected to or confused the
functions of the fdisk(8) and disklabel(8) tools.  This is in a way
exacerbated by the fact that the virtual disks created in AWS do let you
get away without having to create a partition, but you should revisit
lectures two and three.  fdisk(8) is used to create a BIOS partition;
disklabel(8) is used to partition a BIOS partition.


Many of you appear to think that Linux is "modern" and the other Unix
versions are "older".  This is not so.  All the different OS versions we
consider are "modern" in that they are up to date and recent; different
OSes offer different tools, and you should not judge one to be "better"
or "more modern" based on what you are used to or what you find most
quickly on Stackoverflow.  Each has their advantages and disadvantages
that to learn to appreciate will be part of your journey.


Many of you manipulated /etc/fstab in order to mount the disk in
question.  This is not necessary; you can mount any filesystem at any
point, while /etc/fstab merely instructs the OS which filesystems to
mount at boot time.


Many of you appeared to still struggle with the concept of permissions.
If you are logged in as 'root', you do not need sudo(8); you already are
root.  If you are not logged in as 'root', then you may need sudo(8)
or su(1) to elevate privileges for certain tasks.  Running 'chmod 777'
is in virtually 100% of the cases I've encountered in my career a
mistake.  Even if it may help you solve your immediate problem, you
should search for the right way to fix whatever makes you think that you
should give everybody on your system read-, write-, and execute
permissions toa a file or directory.


When you are writing your notes, please do pay attention to the
guidelines spelled out at https://www.cs.stevens.edu/~jschauma/615/text

Please also do not send me any secret keys or access credentials, such
as your AWS Secret Key.  By doing so, you allow me to use your account
(and thus you end up being charged!); this extends to anybody who may
have intercepted the email, or who has gained access to your 'sent-mail'
folder or your email provider's servers.


-Jan