Create a 2GB ram disk results in error

Question

I'm trying to crete a ramdisk of 2gb in centOS 6.2 and the error I get is the following. Any help would be greatly appreciated.

[root@ssb1 ~]# mkfs -q /dev/ram0 2147483648
 mkfs.ext2: Filesystem larger than apparent device size.
 Proceed anyway? (y,n)

grub.conf

title CentOS (2.6.36.4)
    root (hd0,0)
    kernel /vmlinuz-2.6.36.4 ro root=UUID=be58af32-27ac-45fe-8341-715df43497ac rd_NO_LUKS rd_NO_LVM rd_NO_MD rd_NO_DM LANG=en_US.UTF-8 SYSFONT=latarcyrheb-sun16 KEYBOARDTYPE=pc KEYTABLE=us crashkernel=auto rhgb quiet raid=noautodetect elevator=noop ramdisk_size=2147483648

Memory info

[root@ssb1 ~]# free
             total       used       free     shared    buffers     cached
Mem:      49455672    3185524   46270148          0      18228     164792
-/+ buffers/cache:    3002504   46453168
Swap:            0          0          0

How much RAM do you have in your machine, and how large is the RAMdisk going to be? — Frederik, Jul 10 '12 at 12:54
I'm not totally familiar with the built in ramdisk but I'll look into it. Thanks. I'm building this for an appliance and the OS lives on a CF card I want to minimize writes to the card by logging system and our own logs and tmp files to ram. — egorgry, Jul 10 '12 at 14:05
Wow, old skool. `tmpfs` has totally eaten the old ramdisk model for lunch. — womble, Jul 10 '12 at 17:07
I'm trying to keep it real. :) Haven't had a moment today it look at tmpfs. I see it's already mounted on centOS /dev/shm. — egorgry, Jul 10 '12 at 18:33

score 1 · Accepted Answer · edited Mar 20 '17 at 10:16

1

See https://superuser.com/questions/255060/how-can-i-change-the-amount-and-size-of-linux-ramdisks-dev-ram0-dev-ram15

In particular,

mount -t tmpfs -o size=10g none /mnt/point

edited Mar 20 '17 at 10:16

Community

1

answered Jul 10 '12 at 14:11

pjc50

1,720
10
12

killed the legacy configuration left over from fedora 8 install and went with tmpfs. Thanks. – egorgry Jul 16 '12 at 16:36

score 0 · Answer 2 · answered Jul 10 '12 at 13:08

0

Is this a 32 bit OS or a 64 bit OS?

It looks like you are using 3GB of RAM already and creating a 2GB RAM disk would put you over that magic 4GB mark that 32 bit systems can't handle.

answered Jul 10 '12 at 13:08

Ladadadada

26,337
7
59
90

this is a 64bit install. – egorgry Jul 10 '12 at 14:10

Create a 2GB ram disk results in error

2 Answers2