KnoppixCD boot with 3GB of ram...toram..experiment(success)

[lilsirecho]

With 3Gb physical ram installed, I installed the Knoppix CD with:

Knoppix26 toram myconfig=scan (previous install of config)

The result was an install of the CD toram in about 4 minutes. The " system guard" reported a total of 2.21GB of free ram.

A side issue in this experiment.

I had previously set up a USB HDD of 80GB with qtparted to have 4 primary partitions, 40MB ext2, 2GB linux swap, 2GB linux swap, 4GB ext2 and the remainder free.

The effect of this HDD was to supply a total of 4GB of swap to the knoppix CD install which was reported in " system guard" along with the memory figures.

I am booted in this mode at this time with the CD removed from the computer, the "C" drive powered down, the floppy drive powered down, and only one USB HDD powered up (external).

The 4GB partition contains a Knoppix DVD KNOPPIX file which permits the boot of the Knoppix 3.4 CeBit remaster ..toram... when the DVD is loaded in the CD/DVD reader. This provides 4GB of swap but only some 900MB of free memory. It loads in kernel 2.6.3 whereas the CD loads kernel 2.6.5. There are 4.9GB of program material provided in the DVD format (Limited by the legacy of inherent isolinux limits).

One experiment conducted with the system as loaded into ram involved transferring a 300MB file from desktop to a directory created called RAM1. The file transferred at 200MB/sec, thus confirming the true install ..toram..of all data.

My system is athlon1900+ having 3GB of 2100DDRAM.

Examining the characteristics of loading additional data into the memory via file transfer from external sources suggests that the new data drives the memory content already present in physical ram into the swap area (slower, due to USB interface in my system).
I invite comment on this apparent characteristic of memory management. Thus the new data appears in physical ram, and if enough is added, swap begins to build (slower).

I have just begun studying what might happen next, with Linux...anything!

Admittedly, using the "C" drive for swap and Knoppix loading would provide higher speed but this arrangement left my system in pristine condition while the experiment was performed.

I expect to try installing the USB HDD as "C" HDD and compare performance.

[groenewe]

Maybe I'm missing the point here, but it seems to me the "noswap" cheatcode seems to be appropriate when running Knoppix on a machine with 3Gigs of memory...
The fact that swapspace is *slower* to access than is real memory comes as no surprise, it's probably related to the fact that a storage device (hard disk) is being used to simulate the presence of more physical memory than is actually available. I think Linus has the inside scoop on this.

Seriously, the Linux kernel does indeed start to swap out data to available swap devices before physical memory is completely used up, but under normal conditions this results in better system performance. Copying large files around tends the system cache to be favored over other data in memory that gets flushed into the swap area(s). btw. Windows has this problem too, not a surprise considering both use some form of LRU algoritm for memory management as far as I know.
Concluding: If you have 3GB of RAM, combine "toram" with "noswap" when booting the CD. Really. ("Blazingly fast" ring a bell anyone?)
Have fun!

[groenewe]

(text deleted, previous message apparently got posted twice)

[lilsirecho]

groenewe;

Your reply appreciated.

I mentioned the swap detail for completeness, not to leave out any detail, being fully aware that it would be slower from USB (or hard drive, for that matter).

In performing experiments, all observations are reported.

I loaded this post from the KnoppixDVD, HDD installed as HDB, loading same with:

knoppix26 fromhd toram ( no myconfig=scan)

For completeness, the "system monitor..resources" display states used memory 2.1GB (DVD size) and used swap "0 MB of 163MB" (swap file in hda2).

Entering in root: free -otm.....gives: total used free shared buffers cached
Mem: 3037 2135 901 0 72 1949
Swap: 4259 0 4259
Total: 7296 2135 5160

The experiment includes transferring large video files into memory to determine the response of the arrangement, assuming swap will be utilized during the procedure. The consequences of this procedure may indeed be surprising, especially since some of the transfer is at 45MB/sec and the remainder at one-half or less of that speed. What that does to the performance of the OS is at present unknown by this writer. The playback of such a transfer may also be impossible with present playback filters.

The observation I can make at present is that the KnoppixCD install provides greater memory access in the 3GB limits of X86 mobos (standard, single cpu) than the DVD install.

Further study of the application of swap as additional memory is my next objective. I suspect it will be a limited area of application, especially in using USB swap which probably inserts access delays intolerable for some applications.

I try to report all observations, trite or no!

Thanks for your comments and I invite more on the subject of swap use.

[lilsirecho]

At present time, operating with DVD in 3gb RAM IN ..TORAM..MODE WITH ALL POWER REMOVED FROM ALL DRIVES.

System resource monitor says 2.1GB memory in use and 3.9GB of swap free.

Swap use is a complex issue not easily modified.

Would like to swapout much of the 2.1GB to free up memory.

Ideas?

[el_supremo]

At present time, operating with DVD in 3gb RAM IN ..TORAM..MODE WITH ALL POWER REMOVED FROM ALL DRIVES.
System resource monitor says 2.1GB memory in use and 3.9GB of swap free.

I don't understand how you managed to boot the system up without having a functional swap area. If the swap space has 3.9GB free then it must be on a hard drive. But you say they are all powered down. Maybe linux doesn't make sure the swap drive is accessible when it comes up. If that's so, you'll probably end up with a panic (system crash) once you do something that requires that the system swap something out.

Would like to swapout much of the 2.1GB to free up memory.
Ideas?

That 2.1GB is all one file - the large compressed KNOPPIX file from the DVD - and it won't be swapped out beccause you've told linux/knoppix to keep it in ram (with the TORAM option).

Best Wishes
Pete

[lilsirecho]

Pete;

Right you are, the 4GB of swap is on a HDD. The HDD can be recalled in USB with hotplug.

I am running without the HDD at present, but am curious to see what can be done with that large a swap system.

True, the 2.1GB of data is compressed, and is decompressed on-the-fly in the ram cache of the system during use of applications.

The CD version of Knoppix permits the use of swap to meet the ram needs of the install. The actual arrangement of the swap to be provided is not detailed. When loading this DVD, the process displayed while booting indicates three sources of swap available (two from the one HDD and one from another HDD, should that one be installed). At present, only the 4GB swap is encountered because only one hdd was used to load the DVD toram.

Continuing my train of thought, where must the swap file be located to enable the use of swap to extend the ram install? If it is on usb, and the hdd used to load the DVD toram is the "C" drive, what happens?

Regardless of whether the program entered is fully in ram or mostly in ram and some in swap, the situation therein permits some of the DVD compressed data to be in a separate location. Logically, therefore "some of the compressed data" could end up being all of the compressed data without violating the principle of swap use.

I have seen, in my several weeks of playing with this ...toram.. mode . a time or two when the data entered included some of the swap file.

I have also seen cases wherein transferring data into the combination caused the ram use to reduce and the swap to increase. ( I monitor both in system resources)>

I would expect that the swap use would be under memory management control and that knowledge of that part of Linux would probably permit some intelligent swapping especially of large programs hardly ever used. Granted, the compression of the whole install presents a complication in trying to do particular swaps. Perhaps swaps of entire categories would be possible( logically, I am using program A, all others to swap..dependencies?)

So, the premise that Knoppix can use swap to make up a shortage of ram must not apply in the TORAM mode, only applies to the CD version in loading to ram deficient systems.

I attempted to load the DVD TORAM with the swap provided(4GB) while installing with less than 3GB of ram installed. It failed to load toram.

I tried the same exercise with 512MB of ram with a Knoppix CD and it failed to load toram.

This supports the premise I previously stated that swap is not used in TORAM loading but it does appear in the boot process and is identified in the system resources. Some indication exists that there can be interaction as previously stated.

At this time I am not convinced of the use of swap in loading TORAM but do see some evidence that it is available after loading.

Your comments are always welcome.

Ray

[lilsirecho]

Pete;
I ran a bunch of tests since the last post and have confirmed that the memory used goes downward because swap is utilized.

I re-entered the DVD with : Knoppix26 fromhd toram myconfig=scan...
and the system loaded correctly. At that time I used a hdd in "C" for loading the system, CDrom/dvd to enter the boot and a USB hd to use to enter video files.

I used two measures for the performance of the system, the system monitor and the commandline: free -otm...

Initially. there was 9MB of free space in ram. There was zero use of swap.

I transferred 1GB of video into desktop and the memory use fell to 2370MB and the swap went up to 1568MB. Adding another file to desktop (some 380MB) increased the ram to
2670MB and the swap reached 1612.

After running the videos in Kaboodle (sweeping the search bar throughout the pix with no hdd activity indicated) I deleted the two video files from the desktop.

The result was, in free -otm, ram use 1277MB, swap use 1464MB.

I conclude that when memory is exceeded, the system swaps out so memory stays viable and the last entries are in ram. The memory thus transferred to swap stays in swap.

In this experiment the swap was supplied by USB hd for 168MB and the two"C"hd partitions of 2GB each. The readout of swap use in the system resource monitor was erroneous, probably due to the split nature of the swap sources. This encouraged me to use the command line instead (more accurately reported also).

The observations made in this experiment may not hold for all types of data transfers, perhaps.

This experience is the same as previously encountered as I mentioned in the earlier post. It confirms that I haven't lost my mind , completely..just working on it!!

I do not have any idea what will happen with other program selections under these conditions just this one video trial.

__________________________________________________ ___________________

Money talks
Wallet whispers

When is a zero always equal to a one?

What did God do when he made Yogi Bear? He made a boo-boo.

Lassie's favorite is ...cauliflower.

[smorty]

Glad to see someone else using the toram option! I've got this working with knoppix 3.6 on
a 4GB athlon 2.6 dual processor machine. I have a persistant home on a maxtor 80G drive
but otherwise everything runs in ram, and the machine is almost totally silent.
I have a temp-controlled low-noise psu (nexus) and I have stepped the cpu fans down
to the 5V system rail so they're almost silent. Get's a bit hot when I do some heavy
compilation but hey I don't care the machine is stable anyhow hasn't crashed yet,
although this is a software development box I'm not running games. Fanless matrox
video card. The only time it's noisy is during boot when it's copying the cd!

I've got this hooked up to a ups so I'm going to leave it on long-term; I'll post back in
here when I have 6 months uptime!

Here's my free output:
knoppix@ttyp0[KNOPPIX]$ free
total used free shared buffers cached
Mem: 4032832 1899360 2133472 0 67428 1486196
-/+ buffers/cache: 345736 3687096
Swap: 0 0 0

I really, really like the toram mode. I know it's profligate but I love the silence!

The only drawback is that apt-get doesn't work since it tries to write to the ramdisk
which is read-only, and remounting it r/w doesn't seem to work. Am I right in thinking
the image in ram is still compressed as on the cd? Is there anyway to get apt-get
to work when running under toram?

Oh yes, and I can only get it to work under 2.4 kernel not the 2.6, still I'm happy.

Anyway, whoever had the idea of putting the toram option into knoppix deserves
a medal, it's really great!

[smorty]

And someone might find this interesting:

knoppix@ttyp0[knoppix]$ cat /proc/meminfo
total: used: free: shared: buffers: cached:
Mem: 4129619968 1950781440 2178838528 0 69046272 1521922048
Swap: 0 0 0
MemTotal: 4032832 kB
MemFree: 2127772 kB
MemShared: 0 kB
Buffers: 67428 kB
Cached: 1486252 kB
SwapCached: 0 kB
Active: 518656 kB
Inactive: 1128320 kB
HighTotal: 3166208 kB
HighFree: 1588824 kB
LowTotal: 866624 kB
LowFree: 538948 kB
SwapTotal: 0 kB
SwapFree: 0 kB