OS4.1 SWAP partition question

Does it matter where (beginning, middle, end) on the hard drive the OS4.1 SWAP partition is?

Hi,

@RacerX

the access and file transfer is on the outer sectors
faster.

R-TEAM

@R-TEAM

So, I should make it the last partition, right?

Hi,

@RacerX

in the "normal" world - Partitioning tools get from the
first cylinder on the HD to the last - YES ;)
[and the first cylinder is the start in the center]

But if you have a silly tool that get the opposite way
this is maybe different :P

R-TEAM

@RacerX

Quote: What R-Team is saying, is that normally your partitioning software is sequential, and you would normally only add a partition to the end of your existing partitions.
But, and this is a big BUT, this is Amiga and our system born with partitioning, so this is not necessarilly so on an Amiga.
The answers to your question is:-
1. Yes, you can create a swap prtition at the end of your current partitions.
2. No. you cannot create a swap partition at the end of the drive, unless you first partition all the space before it.
3. Yes, you can put the swap partition anywhere on the drive you like.
4. No, the swap partition does not have to be the first partitionon your hard drive.

I had a 5GB partition which was only partially used, I deleted the partition, re-partitioned as two seperate partitions, and made one of them a 1GB swap partition.

@Swoop

Quote:

That's not true - you can leave unpartitioned space between partitions.

@Chris

Quote:
Well, I never new that! Good old AmigaOS.
Thanks fore that, Chris.

@R-TEAM

Quote:Unless you use an at least 10 years old HD it doesn't matter at all on the AmigaOne because of the very slow PCI IDE DMA transfer speeds (about 45 MB/s max.), even the cheapest HD is much faster on the slowest part than that.

@thread

Does anyone knows how to display swap usage statistics (I would like to see that in WB screen title)

TIA
Jack

@joerg

Quote:

So, basically, it doesn't matter.

The reason I'm asking is because I've already put the SWAP partition as the first partition on the drive, but I also left some empty space at the end of the drive. So I could put a SWAP partition at the end of the drive and remove the SWAP partition at the front of the drive and use it to make my boot/Workbench partition bigger.

If I were to delete the SWAP partition and expand the next partition, would I lose the data already on the expanded partition?

@RacerX

If you resize a partition, all data on it would be effectively lost.

It is possible to perform an "Undelete" on the partition after resizing, but there are no guarantees you'll recover everything, and it should really be a last resort.

As with all changes to hard disks, the best advice is to back it up first.

Simon

Hi,

@joerg

mmhh .. you are right :P
but for the theory i`am right :)

and .. have i said already i like an [even nowdays old]
Ultra2-SCSI driver for AmigaOS 4.x ...? *GG*
[mmh ... An good U2SCSI driver with an good Seagate
HD and 80MB/s continous transfer speed on an 2-channel
SCSI card ... -dream- > actual High-End SAS HD`s get
180MB/sec peek and 120 continous]

@RacerX

AmigaOS support ATM not partition resizing without
data loos.

R-TEAM

@RacerX

My experience is that it is most efficient to put the swap partition as close to the partition mostly used when you normally run out of memory.

To simplify:
Put Boot/WB partition first.
Then swap.
Last Work: or other large partitions which are not accessed in their completeness very often.

This makes the head swing the shortest way on average since the swap and boot/WB and beginning of Work: are closest to swap.

If you put it like this:
Boot/WB/programs
Work: (large)
Swap (end of disk)

..the head would need to swing all the way over the large Work: partition everytime you load a program and run out of RAM:, then back to WB to load some more, the over to swap, then back to WB etc.. lot of swing and tear of the drive and slow swapping.

Hi,

@Deniil

the best is the SWAP partition to sit on a second
HD with the WB too.
From WB you only load the prg. and then nothing
more [or only small stuff].
From the work or DATA HD you transfer the most
and this should sit on a seperate HD.

Then you have not the overhead with the mechanic.

R-TEAM

@R-TEAM

Too bad that there's no market for really fast 2-4Gb Solid State disks in PATA/SATA form factor. Would be perfect for stuff such as this :)

Could be an idea for Individual Computers perhaps. A PATA/SATA device with 2 DDR2 PC4200 sockets or some such for up to 4Gb memory. And a setup chip on it that sets it up to look like an empty drive after reboot.

@R-TEAM

Quote:Why do you want to use extremely expensive hardware, for which very likely nobody will ever write a driver for AmigaOS 4.x, just to get about the same speed you even get with the cheapest SATA drives?

(Not on an AmigaOne, there you get only a little bit more than 40 MB, but for example on a SAM440).

Quote:Since both the AmigaOne and SAM440 only have PCI33 slots (the A1 has a PCI66 one, but at least a sii3114 controller doesn't work in it) it's impossible to get such speeds, you'd need at least PCI66 or better PCIe.

Hi,

@joerg

because i HAVE the expensive HW allready here and
in USE and like it.

And the allready supportet SCSI chip on OS4 "have"
2-channel UW2SCSI .. it musst only be used to his
full potential.
A couple of Amiga fans have "expensive" SCSI HW,
if you like in the 68k days an good and fast HD system
you MUSST get good SCSI drives.[maybe not su much
expensive i have - but it is for the future too..]

And expensive is a good medicore SCSI HD that get 80MB/s
transfer speed [the max from UW2SCSI] not more .. more
expensive than a SATA - yes.

I know this high-end speeds immposible ATM on OS4 HW.
But ATM not "one" decent SCSI driver is available, so
i realy dont care ATM for an high-end SAS-Card driver..

It was only IMHO .. i know the SCSI problem will in the
next long time not sortet - so i have already startet to
move from A4000 WITH UW-SCSI to IBM workstation.

Thats the reason i will only buy ONE SAM as little server
and proxy for my network to get the secure and risk-free
internet access over OS4.
For the other things i use WinUAE on my workstation WITH
SCSI.
Even an powerfull OS4 machine is "for me" ATM not from
interesst without SCSI support - sorry.
I know with enough capital and manpower you would happy to
get me and others an good SCSI driver - but it is ATM immposible.
But from the opposite site - sorry,i dont buy an Amga who i get
not more as my +10 Years old A4000.. i dont buy amiga only
"IT is an Amiga" .. a little bit sense musst stay even for an
Fan like me.So 1 SAM for Internet access is enough ATM ...
[my planed 3+ OS4 machines canceled ...and it is realy no the money,
IBM workstations realy not cheap too ]

R-TEAM

@Deniil

Quote:

Right now I have:
SWAP
Boot/WB
Games
Utils
...

That's just about as good, right? The reason I put the SWAP on the drive first is because the install booklet mentioned it first.

@RacerX

I think the answer is that, with existing technology, it makes no difference where you put the partitions.

The intention of putting partitions in a certain order to minimise seek times may be good, but in practice, the disk storage is not organised in a linear fashion. There will usually be several disk surfaces and RW heads, and when a different partition is accessed, it might even be done simply by switching to a different head without moving the arm at all. The firmware in a modern disk is pretty clever at that sort of thing.

@RacerX

That looks quit OK, yes.
My swap is at the end of the disk though, not efficient at all, but that's where I had the room for it... :(

But as someone mentioned, having the swap on a different driver would bet the best. I was thinking about that, but since I often put my second (mostly backup) driver to sleep, it wouldn't be smart to have the swap there, even if it will rarely be used.

@tonyw

I believe that HDs will use all surfaces at the same time in parallel to increase speed. With four surfaces you get a fourfold speed increase AND lower seeks since more data is avaiable "vertically" on the same cylinder rather than "horizontally" over several tracks.

I don't have facts to back this up, but it would seem most logical to me.