Ask Ubuntu is a question and answer site for Ubuntu users and developers. Join them; it only takes a minute:

Sign up
Here's how it works:
  1. Anybody can ask a question
  2. Anybody can answer
  3. The best answers are voted up and rise to the top

The setup:

Thinkpad x40 without harddisk, 1GB of RAM. The hard-disks for these models are very slow, rare and expensive. This is why I installed Ubuntu 11.10 onto the USB. The system will be used for net - FF, and some office docs editing. If possible, I might setup a second PC, used for XBMC.

I have tried live Ubuntu USBs with the same PC and USB, and the setup is OK. I am limited to 4 GBs, though. This is why I chose to perform normal install.

The problems:

The system feels slow, and freezes every other second. I have no swap, only one root partition.

What I have tried:

sudo apt-get install preload

Use memory instead of disk

Add these lines to /etc/sysctl.conf, and reboot.

vm.swappiness = 0
vm.dirty_background_ratio = 20
vm.dirty_expire_centisecs = 0
vm.dirty_ratio = 80
vm.dirty_writeback_centisecs = 0

Mount /tmp onto ramdisk Code:

mkdir /dev/shm/tmp
chmod 1777 /dev/shm/tmp
mount --bind /dev/shm/tmp /tmp

Still, the system is slow to the point of being unusable. Are there any other tweaks that can be done. I read that some parts of the system might be mounted into RAM, and that would be beneficial, but which parts and how to do that. I also read that compressing parts of the system might help, I dont know how to do that , too

share|improve this question
Not directly an answer, but you can replace the Hard Drive with a CF Card e.g.… – arochester Feb 15 '12 at 18:39
H'm, I know this workaround. Sadly, I bought two micro usb 16 gb USB with the sole purpose of serving as hard disks. Since live usbs work way faster than this install, I believe there is a way to get things right on such a system. I don't strive insane copy speeds, just a decent Facebook machine for my girlfriend :-) – deckoff Feb 15 '12 at 21:20
PS. Just checked prices - this seems like a reasonable solution money-wise :) – deckoff Feb 16 '12 at 4:41
up vote 1 down vote accepted

Info on running Ubuntu from RAM:

You can get away from the 4GB Persistence limit of the casper-rw file by using casper-rw and home-rw partitions.

share|improve this answer
Since the PC runs on 1GB of RAM, I wonder if there are system folders I can leave on the USB, and some that I can squashfs and load to RAM.Any ideas? – deckoff Feb 17 '12 at 12:05

I think that hardware controller can be USB-1.1 and no real USB-2.0, thats why its slow, you can try add Swap into ANOTHER USB.

share|improve this answer
I will try in the next few days and report. Thanx for the answer :) – deckoff Feb 16 '12 at 4:36
It seems the problem is the USB drive itself - I cloned the installation to other USB drives, and even though the speed reported are similar, the performance of the 'default' USB is significantly slower – deckoff Feb 18 '12 at 7:48

To fully understand the output I would first check this

hdparm -tT /dev/sdc 

where as your /device/assumed "sdc" replace with correct path. Check your results.

There is a bug report and a fix by modifying /etc/initramfs-tools/modules and adding two lines:





also some reference here:

share|improve this answer
hdparm reports speeds close the the speeds of my hard-drive, but performance of the system is far from the performance of the system when an original hard-disk is used. Thank you for your answer :) – deckoff Feb 16 '12 at 4:37

Xubuntu 14.04 LTS + Firefox 28.0

I had issues using a browser (Firefox) on a Ubuntu that started from USB. I think this is because the browser will write a lot of small files into the cache into the /home/user/.mozilla folder.

Before, I already changed my /tmp to a folder in RAM by adding the following line into /etc/fstab

tmpfs /tmp tmpfs defaults,noatime,nosuid,nodev,noexec,mode=1777,size=1024M 0 0

I found the hidden browser.cache.disk.parent_directory setting to redirect the cache to /tmp/cache, so the cache will be stored to RAM.

Of course this loses the cache everytime you restart the computer, but I hoped (without actually benchmarking it against switching off the cache completely) that it speeds up surfing at least if you stay on one page (let's say Amazon) for one session. I noticed a big speed up against caching on the USB drive.

share|improve this answer

Your Answer


By posting your answer, you agree to the privacy policy and terms of service.

Not the answer you're looking for? Browse other questions tagged or ask your own question.