Red Hat Bugzilla – Bug 214136
kernel panic on boot option 'vmalloc=512M'
Last modified: 2012-06-20 12:13:55 EDT
Description of problem:
when I try to append 'vmalloc=512M' (or 256M) to /etc/grup.conf I get a kernel
panic on reboot.
following is my system spec..
- OS : Redhat Enterprise Linux AS 4 update4
- CPU : Intel(R) Xeon(TM) CPU
- Mem : 1GB
- Controller : Adaptec AIC7901 Ultra320 SCSI adapter
- HDD : SEAGATE 36 GB
kernel panic message :
#### kernel 2.6.9-42.23.ELsmp, 2.6.9-42.ELsmp ####
md: Autodetecting RAID arrarys
md: autorun ...
md: ... autorun DONE.
VFS: Cannot open root device "LABEL=/" or unknown-block (0,0)
Please append a correct "root=" boot option
Kernel panic - not syning: VFS: Unable to mount root fs on unknown-block (0,0)
#### kernel 188.8.131.52y_02 -> kernel version I make myself ####
Filesystem type is ext2fs, partition type 0x83
kernel /vmlinuz-184.108.40.206y_02 ro root=LABLE=/ rhgb quiet
[Linux-bzImage, setup=0x1C00, size=0x1b0226]
[Linux-initrd @ 0x37f91000, 0x5e17f bytes]
Uncompressing Linux... OK, booting the kernel.
initrd extends beyond end of memory (0x37fef17f > 0x20000000)
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(0,0)
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. append vmalloc=512M(or 256M) to kernel boot parameters in /etc/grup.conf
my grub version : 0.96
This can only work on the SMP kernel when the amount of RAM in the box is
significantly less(about 1/2) than 7/8GB - <what was specifiend in vmalloc=>.
Please try either reducing the amount of RAM on the box to 512MB for vmalloc=256M
or to 256MB for vmalloc=512M or use the hugemem kernel where the kernel virtual
size is much larger. Let us know how this works out.
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