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 2.6.17.13y_02 -> kernel version I make myself #### root (hd0,0) Filesystem type is ext2fs, partition type 0x83 kernel /vmlinuz-2.6.17.13y_02 ro root=LABLE=/ rhgb quiet [Linux-bzImage, setup=0x1C00, size=0x1b0226] initrd /initrd-2.6.17.13y_02.img [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): - kernel-smp-2.6.9-42.EL.i686 - kernel-smp-2.6.9-42.23.EL.i686 How reproducible: always Steps to Reproduce: 1. append vmalloc=512M(or 256M) to kernel boot parameters in /etc/grup.conf 2. reboot Actual results: kernel panic Expected results: boot normally Additional info: 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. Larry Woodman
Thank you for submitting this issue for consideration in Red Hat Enterprise Linux. The release for which you requested us to review is now End of Life. Please See https://access.redhat.com/support/policy/updates/errata/ If you would like Red Hat to re-consider your feature request for an active release, please re-open the request via appropriate support channels and provide additional supporting details about the importance of this issue.