| T.R | Title | User | Personal
Name | Date | Lines |
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| 101.1 | Sysnet III Chapter 6 draft available for review | SUPER::WTHOMAS | | Tue Aug 13 1991 16:06 | 11 |
|
A draft of the sixth Sysnet III cahpter entitled:
Maintaining Disks
is available for review in:
SUPER::ES$REVIEW:[SYSNET_III]SYSNETIII_CHAP6.PS
Wendy
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| 101.2 | comments from DC | TEACH::WENDY | | Tue Aug 27 1991 14:30 | 24 |
|
Chapter 6
Maintaining Disks
6-26 This search list stuff 6-26 thru 6-28 to me be in the chapter where they
learn about setting up logical names, because as its shown its not dealing with
devices.
6-32 to me this dosnt really fit in here. Maybe this should be with retrieval
pointers back in the beginning of the chapter.
I was going along really thinking this chapter was great until I hit
all the memory stuff on 6-43. How can memory management be thrown in a chapter
called Maintaing Disks. The same for scheduling and IPL's.
I think the material for memery and scheduling is pretty good, but it dosnt
fit in with the name of the chapter.
6-51 What is the five state model of a process?? Ive always wondered.
Overall the stuff on disk management is good, and I like the fact its all
in one chapter.
Wendy Mullenhoff
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| 101.3 | Capitol Ideas | TEACH::LYNN | | Thu Aug 29 1991 19:18 | 12 |
| SYSNETIII - MAINTAINING DISKS
Chapter 6
Page 20 You use the words "subfile directory". Is this a subdirectory
or something else?
Overall comments - Why near the end of the chapter do you jump to memory
topics? These items have nothing to do with the title -
Maintaining Disks. Just wondered.
Lynn White
Washington D.C.
|
| 101.4 | Module 6 | TEACH::CHUCK | | Tue Sep 03 1991 18:15 | 67 |
| SYSNET III
Chapter 6
page 6 I would like Cylinder bullit to read as one sentence
- All tracks in the same radius on all recording surfaces.
///this seems as a more complete thought///
page 7 SYS ARCH P. 8-15 course has a good figure to put here.
Page 8 SYS ARCH P. 8-19 course has a good figure to put here.
page 10 SYS ARCH P. 8-21 course has a good figure to put here.
Page 11 SYS ARCH P. 8-18 course has a good figure to put here.
page 13 should be related to figure 6-3
page 15 Table 6-2 As is has no real meaning. If a bullit were
added for each item relating to example 6-3 it would be more
meaningful
page 16 An instructor note to explain the 3 File ID numbers
would be great.
page 17 This is great but if we had one showing more extents it
would be more useful.
Page 26-28 These pages belongs in SYSNET II with logical names. Not
here with maintaining disks.
Page 32 Put this with retrieval pointer discussion
Page 34 HEAVY DUTY PROBLEM HERE. Recommend deleting third bullit.
Students laugh at it now in the course it is in, and for good
reason.
1. When a drive goes bad, it could be the cause of
a head crash. Usually the customers cannot detect
this on their own. If it is a head crash, and we
tell them to move the pack to a good drive we just
created a second bad drive. Not a cool move,
especially if we told them to do it!!!!!
2. Customers should be told not to move the unit select
plugs. I used to be in field service and when customers
moved plugs around, the error log would report errors
for each device based on the plug #. I may only
have 1 bad drive but moving plugs could make me
think I had many. I may then think I had a controller
problem or many drives with the same problem.
All in all this is a very good module. Page 1-42 that is.
Page 43 on is o.k. also but does not belong in this module. Most
of it is already taught in sysnet II anyway. Drop it form here.
If you are going to reteach it do it is some other chapter. If
the chapter in sysnet II is not as complete as this info add to
that chapter. We really have to stop the redundancy. The size
of these courses are getting out of hand.
CHUCK
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| 101.6 | Review Cutoff Date | SUPER::MORGAN | | Thu Sep 19 1991 17:35 | 11 |
|
In order to make the pilot schedule, Monday 9/23/91 will be the
review cutoff date.
Any comments entered after that date will be considered after the
pilot.
Thanks for all of your comments,
Bonnie
|
| 101.7 | Shadow & stripe details | SUPER::MATTHEWS | | Fri Oct 04 1991 14:34 | 4 |
| System Mgt II has an appendix with details on shadowing & striping.
Should we include it here?
Val
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| 101.8 | Keep it in the Appendix | DLO10::TARLING | | Mon Oct 07 1991 10:33 | 5 |
|
Yes, keep shadowing, and striping in the appendix.
Arnold.
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| 101.9 | In an Appendix. | MINDER::GRAVESG | Geoff Graves,EDU(UK); DTN 851 2637 | Thu Oct 10 1991 07:09 | 11 |
| Re .7
Yes, put Shadowing and Striping in this module, but DEFINITELY in an
Appendix!
That way, the instructor can cover as much, or as little, as necessary
for a given class, or individual students. I've found that some students
positively object to being told about layered products on a course, some
see it as a "sales pitch" even though it's not.
(Well, maybe only a small one ;-))
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| 101.10 | Disk chapter review | SOAEDS::TRAYSER | Seniority means a bigger shovel! | Sun Feb 23 1992 20:07 | 67 |
| Chapter 6 is mostly lifted from the existing SysMgr II course. It jumps
around an awful lot and doesn't have a focus of "This is a System Manager
course". A good deal of information is included in this course that is
best put in programmer courses, Internals courses, Hardware courses,
etc. There are a few pages that I plan on skipping because of limited
interest (and application) for system managers.
6-10, 3rd bullet --
This is WRONG. There is a really good discussion of sizing the
cluster size in the VMStuning conference (note 946). Basically,
if you can afford the disk space, pick a large cluster size, maybe
up to the number of blocks in a track. Most important to realize
is that there is virtually NO time lost in moving between tracks
in the same cylinder. A more accurate statement might be to have
the cluster size divisible into the cylinder size. Read the stuff
in the notes files and explain the issues to the students, then let
them make a decision. However, the statement in the book as it stands
is not supportable -- remove it.
6-13 --
Format problems with bullets 2 & 4.
6-15a, 2nd bullet --
This is wrong. The 750 used to be the only system that needed to use
the disk based VMB (most others got VMB from the boot media, like the
780, etc.), but that changed several years ago. 6000 systems can make
use of WRITEBOOT/VMB as can 82xx, 83xx and (I think) the 9000. The
bootblock points to this file via LBN.
6-20, 6-21 --
These diagrams are pretty, but basically useless for System Managers
that have only take SysNet I & II. Nothing really useful for the
system manager. Put these on instructor pages, they are simple enough
for us to draw on the board in less than 30 seconds if we need them.
I plan on skipping these pages.
6-22a --
EMPTY. How about a instructional tip: Take the diagram on 6-22 and
"walk" down it showing how accessing the file of [course]test.dat will
cause 6 or more disk accesses. Leads nicely into a short discussion
of disk caching which will/could be covered in the tuning chapter. Also
useful to explain the impact of heavy usage of sub-directories.
6-22 --
Nice diagram, see comments above. Useful, appropriate to system managers
and brief. But we need some "text" as mentioned.
6-25 --
Isn't this material covered in SysNet I or II? If not, it should be.
6-38, 6th bullet --
2nd dash includes the first dash items. What was supposed to be here?
6-41 --
Sales Stuff. I can smell it a mile away! What do all of these have in
common? HEAVY disk activity, often large records, many sequential blocks
read or written, numerous data files, but generally a few hot files and
a few hot spots. Don't put this stuff on the student's page, it is
useless, put it on the instructor's page so we can give them examples
of the type of applications that make the disk demands mentioned.
MAJOR item missed...to get the good performance the disks should be on
separate controllers, otherwise the performance gain is minimal (if any).
More later
$
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| 101.11 | | SUPER::MATTHEWS | | Wed Feb 26 1992 10:10 | 12 |
| > Chapter 6 is mostly lifted from the existing SysMgr II course. It jumps
> around an awful lot and doesn't have a focus of "This is a System Manager
> course". A good deal of information is included in this course that is
> best put in programmer courses, Internals courses, Hardware courses,
> etc.
OK, this is an example of a tricky balance. For the most part I've been
trusting the Sys Mgt II material because we had good field
participation in its last update, and I hate to rewrite material that
was carefully written in the first place. On the other hand, if it
doesn't work, it doesn't work. We can certainly use recommendations
like this for reducing the amount of material.
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