online prescription solutions
online discount medstore
pills online
buy lorazepam without prescription
xanax for sale
buy xanax without prescription
buy ambien without prescription
ambien for sale
buy modafinil without prescription
buy phentermine without prescription
modafinil for sale
phentermine for sale
lorazepam for sale
buy lexotan without prescription
bromazepam for sale
xenical for sale
buy stilnox without prescription
valium for sale
buy prosom without prescription
buy mefenorex without prescription
buy sildenafil citrate without prescription
buy adipex-p without prescription
librium for sale
buy restoril without prescription
buy halazepam without prescription
cephalexin for sale
buy zoloft without prescription
buy renova without prescription
renova for sale
terbinafine for sale
dalmane for sale
buy lormetazepam without prescription
nobrium for sale
buy klonopin without prescription
priligy dapoxetine for sale
buy prednisone without prescription
buy aleram without prescription
buy flomax without prescription
imovane for sale
adipex-p for sale
buy niravam without prescription
seroquel for sale
carisoprodol for sale
buy deltasone without prescription
buy diazepam without prescription
zopiclone for sale
buy imitrex without prescription
testosterone anadoil for sale
buy provigil without prescription
sonata for sale
nimetazepam for sale
buy temazepam without prescription
buy xenical without prescription
buy famvir without prescription
buy seroquel without prescription
rivotril for sale
acyclovir for sale
loprazolam for sale
buy nimetazepam without prescription
buy prozac without prescription
mogadon for sale
viagra for sale
buy valium without prescription
lamisil for sale
camazepam for sale
zithromax for sale
buy clobazam without prescription
buy diflucan without prescription
modalert for sale
diflucan for sale
buy alertec without prescription
buy zyban without prescription
buy serax without prescription
buy medazepam without prescription
buy imovane without prescription
mefenorex for sale
lormetazepam for sale
prednisone for sale
ativan for sale
buy alprazolam without prescription
buy camazepam without prescription
buy nobrium without prescription
mazindol for sale
buy mazindol without prescription
buy mogadon without prescription
buy terbinafine without prescription
diazepam for sale
buy topamax without prescription
cialis for sale
buy tafil-xanor without prescription
buy librium without prescription
buy zithromax without prescription
retin-a for sale
buy lunesta without prescription
serax for sale
restoril for sale
stilnox for sale
lamotrigine for sale

Ramdisk: How do you install and set up Ramdisk under Linux (CentOS, RHEL, Fedora)?


Ramdisk is very good to have if you want something to stay in memory.   Files in memory makes it so you can access them with out having to access hard drive all the time.  Perfect candidates would be things which do not change eg. web images or downloadable files, etc.  If you have Linux Kernel 2.4 or later, you already have support of ramdisk built in.  You can check if ramdisk is setup by doing: 

# dmesg | grep RAMDISK
RAMDISK driver initialized: 16 RAM disks of 16384K size 1024 blocksize

You should get above output on CentOS and RHEL.  Other linux flavors will have similar output as well.  If you would like to see how they are named and what you would need to refer to, do the following:

# ls -l /dev/ram*
lrwxrwxrwx 1 root root 4 Apr 24 12:05 /dev/ram -> ram1
brw-rw---- 1 root disk 1, 0 Apr 24 12:05 /dev/ram0
brw-rw---- 1 root disk 1, 1 Apr 24 12:05 /dev/ram1
brw-rw---- 1 root disk 1, 10 Apr 24 12:05 /dev/ram10
brw-rw---- 1 root disk 1, 11 Apr 24 12:05 /dev/ram11
brw-rw---- 1 root disk 1, 12 Apr 24 12:05 /dev/ram12
brw-rw---- 1 root disk 1, 13 Apr 24 12:05 /dev/ram13
brw-rw---- 1 root disk 1, 14 Apr 24 12:05 /dev/ram14
brw-rw---- 1 root disk 1, 15 Apr 24 12:05 /dev/ram15
brw-rw---- 1 root disk 1, 2 Apr 24 12:05 /dev/ram2
brw-rw---- 1 root disk 1, 3 Apr 24 12:05 /dev/ram3
brw-rw---- 1 root disk 1, 4 Apr 24 12:05 /dev/ram4
brw-rw---- 1 root disk 1, 5 Apr 24 12:05 /dev/ram5
brw-rw---- 1 root disk 1, 6 Apr 24 12:05 /dev/ram6
brw-rw---- 1 root disk 1, 7 Apr 24 12:05 /dev/ram7
brw-rw---- 1 root disk 1, 8 Apr 24 12:05 /dev/ram8
brw-rw---- 1 root disk 1, 9 Apr 24 12:05 /dev/ram9
lrwxrwxrwx 1 root root 4 Apr 24 12:05 /dev/ramdisk -> ram0

All those ramdisks listed have same size.  In above example, they are all 16MB.  Let us change that so we have more space allowed.  Note that I say allowed and not allocated.  We allocate space in one of the later steps by formatting one of the drives above.   Let us set it up so we have 128 MB.  Since this has to be in multiples of 1024, we will setup Ramdisk to have 131072K. 

vi /etc/grub.conf

Find first line which looks similar to following:

kernel /vmlinuz-2.6.9-42.0.10.EL ro root=/dev/VolGroup00/LogVol00

add ramdisk_size=131072 to the end of the line.  Now your line should look like:

kernel /vmlinuz-2.6.9-42.0.10.EL ro root=/dev/VolGroup00/LogVol00 ramdisk_size=131072 Save and exit grub.conf.  At this point you have it configured to have ramdisk with new size but it does not take effect until you reboot your system.  Once you have rebooted your system, we can start doing rest of configurations.

mke2fs -m 0 /dev/ram0

This will format the ram0 ramdrive for us to use. At this point, kernel will allocate space for you.  Let us setup Ramdisk mount point so we can use it.  We will also have it be owned by user “sunny” so that user can read/write to that mount.

mkdir /home/ramdisk
mount /dev/ram0 /home/ramdisk
chown sunny.sunny /home/ramdisk

At this point you should be able to type:  mount and see your new Ramdisk drive mounted on /home/ramdisk

Remember that everything you put on this drive will be gone if you reboot your server.  If you unmounted the Ramdisk drive and remounted it, your files will still be there.  It is because your system has that much ram set aside for your Ramdisk and will not use it for anything else.   If you would like to setup Ramdisk the same next time you boot up, add these lines to your /etc/rc.local files.

mke2fs -m 0 /dev/ram0
mount /dev/ram0 /home/ramdisk
chown sunny.sunny /home/ramdisk

————————————-
DISCLAIMER: Please be smart and use code found on internet carefully. Make backups often. And yeah.. last but not least.. I am not responsible for any damage caused by this posting. Use at your own risk.


2 Responses to “ Ramdisk: How do you install and set up Ramdisk under Linux (CentOS, RHEL, Fedora)? ”

  1. February 20th, 2011 | 1:11 pm

    [...] minecraft server inside it because my i/o is very abysmal for some reason and following this guide: http://crazytoon.com/2007/06/01/ramd…s-rhel-fedora/ it says to find the line in grub.conf that is similar to "kernel /vmlinuz-2.6.9-42.0.10.EL ro [...]

  2. November 2nd, 2011 | 3:16 am

    what about Ubuntu?

Leave a reply

*
To prove that you're not a bot, enter this code
Anti-Spam Image