Can't get 7.6.1 Live USB to use less than half of RAM

[amdijefri]

Hello, everyone. I am new to Knoppix and the forum but not UNIX/Linux. I am trying to respect everyone's time and have read the FAQ and searched the forums and the Internet using a wide variety of keywords to try to find the answer myself with no luck. I am posting as a last resort. Any help would be greatly appreciated.

I have a Dell R900 with 128GB of RAM but no disks (I can't afford to buy any at this time). I created a Knoppix 7.6.1 Live USB drive using these instructions but when I booted up the system was consuming 64GB RAM in rootfs, which is not only overkill but makes it impossible to do the graph visualization that prompted this setup in the first place because I need every last MB of RAM for the Java VM. I searched around and discovered the ramdisk_size parameter and modified syslinux.cfg, syslnx32.cfg, and syslnx64.cfg to add "ramdisk_size=2097152" (which I understand to mean 2GB) to the APPEND statements using these instructions. Knoppix is still consuming 64GB in the rootfs no matter what permutations I try, and I'm up into the dozens of attempts at this point. There was a recent post that might be related to my problem but there is no definitive answer in that thread. I do not see any other cheat codes that might be applicable. Can anyone help? Thanks in advance.

[fredvej]

When I boot Knoppix 7.6.1 of an ISO file on a harddisk with knoppix64, I get this:

# cat /proc/cmdline 
lang=de video=vga16fb:off apm=power-off nomce libata.force=noncq hpsa.hpsa_allow_any=1 loglevel=1 BOOT_IMAGE=/boot/isolinux/linux64 bootfrom=//KNOPPIX_V7.6.1DVD-2016-01-16-EN.iso lang=en tz=Europe/Copenhagen keyboard=dk xkeyboard=dk no3d

# free -m 
              total        used        free      shared  buff/cache   available
Mem:          15975         112       15357          31         505       15744
Swap:          4095           0        4095

# df -m
Filesystem     1M-blocks  Used Available Use% Mounted on
rootfs              7986     1      7986   1% /
/dev/sdb3          15999 10182      4982  68% /mnt-iso
/dev/loop1          4249  4249         0 100% /mnt-system
tmpfs              12780     3     12778   1% /ramdisk
/dev/cloop          9691  9691         0 100% /KNOPPIX
/dev/cloop1          451   451         0 100% /KNOPPIX1
unionfs            12780     3     12778   1% /usr
tmpfs                 20     4        17  16% /run
tmpfs                 10     1        10   1% /UNIONFS/var/lock
tmpfs                100     1       100   1% /UNIONFS/var/log
tmpfs               2048     1      2048   1% /tmp
udev                  20     0        20   0% /dev
tmpfs               2048     0      2048   0% /dev/shm
tmpfs               1598     1      1598   1% /run/user/1000
tmpfs               1598     0      1598   0% /run/user/0

If I add the boot parameter ramdisk=1G I get thhis:

# cat /proc/cmdline 
lang=de video=vga16fb:off apm=power-off nomce libata.force=noncq hpsa.hpsa_allow_any=1 loglevel=1 BOOT_IMAGE=/boot/isolinux/linux64 bootfrom=//KNOPPIX_V7.6.1DVD-2016-01-16-EN.iso lang=en tz=Europe/Copenhagen keyboard=dk xkeyboard=dk no3d ramdisk=1G
 
# free -m
              total        used        free      shared  buff/cache   available
Mem:          15975         114       15351          32         509       15742
Swap:          4095           0        4095

# df -m
Filesystem     1M-blocks  Used Available Use% Mounted on
rootfs              7986     1      7986   1% /
/dev/sdb3          15999 10182      4982  68% /mnt-iso
/dev/loop1          4249  4249         0 100% /mnt-system
tmpfs               1024     3      1022   1% /ramdisk
/dev/cloop          9691  9691         0 100% /KNOPPIX
/dev/cloop1          451   451         0 100% /KNOPPIX1
unionfs             1024     3      1022   1% /usr
tmpfs                 20     4        17  16% /run
tmpfs                 10     1        10   1% /UNIONFS/var/lock
tmpfs                100     1       100   1% /UNIONFS/var/log
tmpfs               2048     1      2048   1% /tmp
udev                  20     0        20   0% /dev
tmpfs               2048     0      2048   0% /dev/shm
tmpfs               1598     1      1598   1% /run/user/1000
tmpfs               1598     0      1598   0% /run/user/0

If I add the boot parameter ramdisk=8G I get thhis:

# cat /proc/cmdline 
lang=de video=vga16fb:off apm=power-off nomce libata.force=noncq hpsa.hpsa_allow_any=1 loglevel=1 BOOT_IMAGE=/boot/isolinux/linux64 bootfrom=//KNOPPIX_V7.6.1DVD-2016-01-16-EN.iso lang=en tz=Europe/Copenhagen keyboard=dk xkeyboard=dk no3d ramdisk=8G
 
# free -m
              total        used        free      shared  buff/cache   available
Mem:          15975         114       15355          32         505       15742
Swap:          4095           0        4095

# df -m
Filesystem     1M-blocks  Used Available Use% Mounted on
rootfs              7986     1      7986   1% /
/dev/sdb3          15999 10182      4982  68% /mnt-iso
/dev/loop1          4249  4249         0 100% /mnt-system
tmpfs               8192     3      8190   1% /ramdisk
/dev/cloop          9691  9691         0 100% /KNOPPIX
/dev/cloop1          451   451         0 100% /KNOPPIX1
unionfs             8192     3      8190   1% /usr
tmpfs                 20     4        17  16% /run
tmpfs                 10     1        10   1% /UNIONFS/var/lock
tmpfs                100     1       100   1% /UNIONFS/var/log
tmpfs               2048     1      2048   1% /tmp
udev                  20     0        20   0% /dev
tmpfs               2048     0      2048   0% /dev/shm
tmpfs               1598     1      1598   1% /run/user/1000
tmpfs               1598     0      1598   0% /run/user/0

The RAM disk size is different, but free shows nearly the same memory use.

[Werner P. Schulz]

I have a Dell R900 with 128GB of RAM but no disks (I can't afford to buy any at this time). I created a Knoppix 7.6.1 Live USB drive using these instructions but when I booted up the system was consuming 64GB RAM in rootfs,

Why did you use this curious instruction of superuser.com instead of → Flash disk install?
To see, what's going wrong please tell us like the posting above your output of
cat /proc/cmdline
free -m
df -h

[amdijefri]

I reinstalled using the Flash disk install instructions. I don't recall how I came across those instead of the official instructions.

knoppix@Microknoppix:~$ cat /proc/cmdline
lang=de video=vga16fb:off apm=power-off nomce libata.force=noncq hpsa.hpsa_allow_any=1 loglevel=1 BOOT_IMAGE=linux64 lang=en apm=power-off initrd=minirt.gz nomce libata.force=noncq hpsa.hpsa_allow_any=1 loglevel=1 ramdisk=1G

knoppix@Microknoppix:~$ free -m
              total        used        free      shared  buff/cache   available
Mem:         128999         221      128411           8         366      128675
Swap:          4095           0        4095

knoppix@Microknoppix:~$ df -h
Filesystem      Size  Used Avail Use% Mounted on
rootfs           63G   48K   63G   1% /
/dev/sda1       4.6G  4.2G  389M  92% /mnt-system
tmpfs           1.0G     0  1.0G   0% /ramdisk
/dev/cloop      9.5G  9.5G     0 100% /KNOPPIX
/dev/cloop1     451M  451M     0 100% /KNOPPIX1
/dev/sda2        26G  4.7M   26G   1% /KNOPPIX-DATA
unionfs          26G  4.7M   26G   1% /usr
tmpfs            20M  3.2M   17M  16% /run
tmpfs            10M     0   10M   0% /UNIONFS/var/lock
tmpfs           100M   56K  100M   1% /UNIONFS/var/log
tmpfs           2.0G   32K  2.0G   1% /tmp
udev             20M     0   20M   0% /dev
tmpfs           2.0G     0  2.0G   0% /dev/shm
tmpfs           612M  4.0K  612M   1% /run/user/1000