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linux_on_sd_card_improving

Why?

On my eeepc I have integrated memory card (SD MMC, etc etc) reader and before to delete windows I want have netbook like new, without multiboot operating system, so I thought to install a mini linux distro on SD for secure navigation on internet or data recovery or to have linux (I use my old laptop distro from external HD usually, and is not practical) or for low energy consumption. The installation that I do includes:

  • openbox with windows manager
  • nodm for login
  • some terminal monitor, tool and other:
    • tmux, htop, iftop, hdparm
  • for wifi navigation I prefer visual utility and I installe network-manager with gnome applet
  • for entertainment:
    • mocp for music
    • smplayer for video

First analysis

I'm using a SD with 2GB and I'm making test from another linux, linux distro for SD is debian squeeze.

fdisk -l show this

Disk /dev/sdc: 2014 MB, 2014838784 bytes
62 heads, 62 sectors/track, 1023 cylinders
Units = cylinders of 3844 * 512 = 1968128 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x30d630d5

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1             764        1024      499712   82  Linux swap / Solaris
Partition 1 has different physical/logical beginnings (non-Linux?):
     phys=(182, 173, 56) logical=(763, 29, 15)
Partition 1 has different physical/logical endings:
     phys=(244, 227, 47) logical=(1023, 28, 60)
Partition 1 does not end on cylinder boundary.
/dev/sdc2               1         764     1466368   83  Linux
Partition 2 has different physical/logical beginnings (non-Linux?):
     phys=(0, 32, 33) logical=(0, 33, 3)
Partition 2 has different physical/logical endings:
     phys=(182, 173, 55) logical=(763, 29, 14)
Partition 2 does not end on cylinder boundary.

Partition table entries are not in disk order

exec sometime hdparm -tT show this

/dev/sdc:
 Timing cached reads:   1268 MB in  2.00 seconds = 634.14 MB/sec
 Timing buffered disk reads:   26 MB in  3.24 seconds =   8.03 MB/sec

/dev/sdc:
 Timing cached reads:   1196 MB in  2.00 seconds = 598.17 MB/sec
 Timing buffered disk reads:   26 MB in  3.20 seconds =   8.12 MB/sec

It's very slow

Some proplems and solution

On SD card 2 GB can be little, I thought to create a ext4 filesystem on image on windows partition, I think it's possible. I can't do for now, but if I create a file with dd like

dd if=/dev/zero of=/home/dir/file.img bs=512 count=**SIZE** 
and then I do mkfs.ext4 /home/dir/file.img and endly in /etc/fstab add somethins like
 /home/dir/file.img /mnt/dir       ext4    defaults        0       0
maybe to work

New test

I tried latest knoppix on SD and is better way because:

  • default settings better for distro on SD
  • you can use crypto filesystem easy
  • you can install apps with normal distro
  • you can save your settings
  • don't use swap

See Also

linux_on_sd_card_improving.txt · Last modified: 2013/11/25 22:16 (external edit)