Some basic questions to the OS/2 gurus

Some basic questions to the OS/2 gurus

Post by Wayne Torbo » Wed, 09 Nov 1994 14:13:45



A couple of questions about OS/2 "Warp," which recently
appeared on local store shelves for only $80.00.

I am a Windows user intrigued by the notion of being able to
multitask my DOS and Windows apps with little system slowdown.
I would like to know a few things before I commit.

1. I've heard that OS/2 for Windows has to load a copy of
Windows 3.1 for each Windows app started. Has this changed with
Warp? How many Windows apps could I expect to be able to run
with an 8-Meg system?

2. What are the advantages and disadvantages of OS/2's high
performance file system? Would it be wise to use this, as all
of my old files are on the older system (FAT file system)

Been thinking about OS/2 for a long time; maybe now's my
chance.

......................................
Wayne Torborg

CompuServe  71221,3453
......................................

 
 
 

Some basic questions to the OS/2 gurus

Post by Alistair James Robert You » Wed, 09 Nov 1994 21:55:45




>1. I've heard that OS/2 for Windows has to load a copy of
>Windows 3.1 for each Windows app started. Has this changed with
>Warp? How many Windows apps could I expect to be able to run
>with an 8-Meg system?

OS/2 never had to load more than one copy of Windows for each app. It can,
but it defaults to running them all in the same app for speed. The
advantage comes when you have an app that requires a lot of system resources
or one that tends to GPF a lot. By running them in a separate session you
can give them all the resources they require, and ensure that when they
crash everything else goes on running.

Quote:>2. What are the advantages and disadvantages of OS/2's high
>performance file system? Would it be wise to use this, as all
>of my old files are on the older system (FAT file system)

Advantages of HPFS:
If the drive is larger than 60 Mb, and you have 8Mb of memory or more, go
for it! HPFS gives better performance than FAT and is considerably
more reliable; i.e. it can preserve your data in the event of power
failures, crashes, or bad sectors during writes. Also, and in my case
most importantly, on large drives it wastes a LOT less space. On my drive C
(345 Mb), when I reformatted from FAT to HPFS before installing, my free s    
space went up by 15Mb.

Disadvantages of HPFS:
Well ... none, really. The only thing that might cause a few problems is
that DOS can't read it. DOS apps running under OS/2 can read it happily,
but booting from a DOS floppy won't even see the drive. If you do have
some things that won't run under OS/2 (not very likely, apart from some
games), it's probably better to leave a small FAT partition for them than
make the entire drive FAT.

Whoops, I forgot to mention long file names... HPFS has them, FAT doesn't,
but you probably knew that anyway! :-)

Hope this helps...

Alistair
------------------------------------------------------------------------
Alistair Young -- Arkane Systems Software Development & PC Consultancy
The opinions above are my company's, because I OWN it!

"Time flies like an arrow, fruit flies like a banana" - Anonymous
------------------------------------------------------------------------

 
 
 

Some basic questions to the OS/2 gurus

Post by The TEAMIBM Netwo » Thu, 10 Nov 1994 15:47:41


Quote:>1. I've heard that OS/2 for Windows has to load a copy of
>Windows 3.1 for each Windows app started. Has this changed with
>Warp? How many Windows apps could I expect to be able to run
>with an 8-Meg system?

By default, all Windows apps load into *one* WinOS/2 session. You do
have the option of having as many sessions as you feel your system
can sustain, though. On an 8MB system, the number of Windows apps would
depend on how large they were......Word 6.0 and Excel 5.0 together would
be a fairly heavy load - but they should go just fine, but for the
Windows 64Kb enviroment segment limit. I keep hearing this is a problem
when trying to run these two apps together with data in any quantity.
Perhaps someone can exand on this?

With Warp, you would have about 4-5 Mb free for apps - depending on
how large a disk cahe you want. I recommend 256Kb of cache - maximising
app memory and reducing swapping. Using only one one file system -
FAT or HPFS - will also keep the Ram requirement down as you won't need
to cache both.

Quote:>2. What are the advantages and disadvantages of OS/2's high
>performance file system? Would it be wise to use this, as all
>of my old files are on the older system (FAT file system)

HPFS is more robust than FAT. It detects/handles/recovers from disk
errors much more effectively. It's CHKDSK doesn't just fix directory
errors - it can recover entire file systems by reading the disk byte
by byte......depending on which of the three settings you use.

HPFS takes advantage of the physical characteristics of your disk by
locating the file system components near the seek-centre of the volume
(where your read/write heads are more likely to be) and by allocating
the Fnodes that anchor each file/directory as close to each as possible.
Files are not fragmented on allocation with HPFS as the file system
maintains bitmaps of empty space on the disk and can work out not just
how to allocate it in a single extent - but also *where* to allocate
it in order to keep it close to the Fnode it is anchored to.

Directories can be of any size and are built up from 2KB directory
blocks which are allocated as four consecutive sectors on the disk.
The file system will attempt to allocate directory blocks in the
directory band (located at the seek centre, as above) Once that directory
band is full, the directory blocks are allocated wherever space is
free. The entries in a directory block are sorted in binary lexical
order of their name fields. When searching for a specific name, the file
system goes through the directory block until it either finds
a match - or finds a name that is lexically greater than the target.
When found, the file system then extracts the binary-tree pointer
from the entry.

The net result is faster access to information about files and where
they are stored. Therefore faster access.

Even better, HPFS is more efficient with disk space. This is because
the minimum allocation is 512bytes. FAT's minimum is 2Kb. I did a
test yesterday on a 55MB partition. I installed two identical
warp systems. One on Fat and one on HPFS. the HPFS partition had
1.3Mb more free space - due, I presume to small files not wasting
up to almost 2Kb on every allocation. On larger partitions, the savings
are even greater.

On a 1gig partition, about 50Mb are lost to HPFS file system overheads...
but this is puny compared to what FAT would lose with a minimum
allocation unit if 64KB!!! Imagine each icon getting its own 64Kb
space allocation.

So....HPFS saves you time, space, loss of data (overall - I prefer it
to FAT in this regard) and provides 254 character filenames *and*
the support for Extended Attributes (included with each file) which
form the basis for OS/2's OO user interface.

HPFS has a lot to recommend it. But to use it with your existing
Windows system, you will have to back that up and restore it onto
an HPFS file system to use it. The OS/2 backup program will do the
job - or INFO's ZIP and UNZIP, if you have enough disk space.

Steve

 
 
 

Some basic questions to the OS/2 gurus

Post by Doug Azzari » Thu, 10 Nov 1994 04:41:22



Quote:>A couple of questions about OS/2 "Warp," which recently
>appeared on local store shelves for only $80.00.

Once you look inside the box, you'll probably agree that this is the best
software bargain to come along in years.

Quote:>I am a Windows user intrigued by the notion of being able to
>multitask my DOS and Windows apps with little system slowdown.
>I would like to know a few things before I commit.

An informed buyer - what a great idea!

Quote:>1. I've heard that OS/2 for Windows has to load a copy of
>Windows 3.1 for each Windows app started. Has this changed with
>Warp? How many Windows apps could I expect to be able to run
>with an 8-Meg system?

You've heard wrong.  OS/2 "CAN" load a copy of windows for each
windows app, but it isn't "REQUIRED."  Why would you want a separate
copy of windows for each app?

 - Buggy WIN Apps that go down in flames won't be able to torch your
   other apps on the way

 - HUGE WIN Apps that suck up that 64K of resources.  You may not be able
   to run Word & Excel at the same time under win 3.x, but you can under
   Warp.

The downside is that it takes lots of extra RAM to do this.  It's not the
default under Warp (and never has been), but the option is there.  How many
WinApps can you run at one time?  It depends on how fast you want them to
run.  OS/2 will use "virtual RAM" so you'll never run out of RAM (until
you run out of disk space), but the system will slow down if you've got
too much running at once.  I've got 16M of RAM, and right now I've got
16 apps up & running (a compiler, a host program, my newsreader, 2 editors,
an FTP server, an async comm program and a couple of "apps under development").

Quote:>2. What are the advantages and disadvantages of OS/2's high
>performance file system? Would it be wise to use this, as all
>of my old files are on the older system (FAT file system)

HPFS allows you to use long file names (up to 254 characters), it does not
fragment as badly as FAT, it uses btrees to store filenames, and you can
have a 64G partition WITHOUT huge clusters (the allocation unit in HPFS
is always 512 bytes).  If you don't need to boot "vanilla" DOS much, HPFS
is the way to go.  If you need "vanilla" DOS, reserve one partition for
DOS, and make the rest HPFS.

Quote:>Been thinking about OS/2 for a long time; maybe now's my
>chance.

There's never been a better time to try OS/2!

 -- Doug Azzarito
    "The OS/2 Guy"

 
 
 

1. 2 questions for OS/2 gurus...

Two quick ones:

How do I switch the orientation of the mouse buttons in DOS sessions?  Is
there a command line switch?

Also, how do I disable my soundblaster support from some of my win-os2
sessions so I can run more than one session at a time withouth getting
that device already in use error?  I tried just changing the audio
adapter setting to "none", but I still get the error.

Thanks,

Steve

2. FA: Sinclair Spectrum+ 128k

3. multitasking & speed: question for os/2 Guru?

4. CAD Operator needed

5. Question to OS/2 sound and device driver gurus...

6. WARNING

7. Question for OS/2 gurus

8. Sound Recorder questions

9. Basic Questions About OS/2

10. Basic OS/2 Questions ...

11. basic OS/2 questions

12. Various basic OS/2 questions

13. basic questions- OS/2 NFS