Red Hat Bugzilla – Bug 64546
Computer hang on "Remounting root file system in read/write mode"
Last modified: 2005-10-31 17:00:50 EST
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Description of problem:
I just tried to install v7.3 on a computer previously running 7.2 perfectly
without a hitch.
I re-formatted the hard disks (no upgrade) and did a fresh install, the
installation procedure went on smoothly but when rebooting after
install the computer locked up after showing the message:
Remounting root file system in read/write mode:
I didn't get the OK and the only way out was a ctrl-c and a reboot, then it
The computer is a MSI K7T Turbo2 motherboard, AMD Duron 1200MHz CPU,
256MB SDRAM, 3 IDE hard disks and an IDE cd-rom. No SCSI interface in the box.
Version-Release number of selected component (if applicable):
Steps to Reproduce:
1. Simply Reboot
2. Reboot from the floppy created with install.
3. Complete re-install from scratch with different choices between everything
from full install to minimum.
Failure every time.
Actual Results: Always the same, the system hangs after displaying the
message about "remounting root file system in read/write mode". The green "OK"
never shows up.
I've waited for 45 minutes, just to be sure...
Expected Results: I expected the usual boot up, and a success in the the
remount as it has always done with version 7.2. (Also v7.2 with a 2.4.18
kernel compiled from the kernel.org sources).
As mentioned before:
MSI K7T Turbo2 motherboard (VIA KT266 chipset)
AMD Duron 1200MHz CPU
3 IDE hard disks
1 IDE CD-Rom
1 3Com 3c905 ethernet adapter
1 AGP Diamond Fire GL 1000 Pro 8MB graphics card.
The system has always worked flawlessly with version 7.2 of RedHat linux.
OK. Boot the installer in rescue mode.
Edit /etc/sysctl.conf on your installed system so that it says:
kernel.sysrq = 1
Then, when booting the system, when it hangs, hit
- what is the current process
- what processes are currently running?
When I hit alt-sysreq-p I get only the text "Show Regs", nothing else.
When hitting alt-sysreq-t I get "Show State", nothing else...
Also, edit /etc/sysconfig/init, and set LOGLEVEL to 7; sorry, should have
mentioned that originally.
You might also try forcing a fsck by touching /forcefsck
I must say that I'm really confused now...
I disconnected the disks I've been running on before and put in another one,
just to be sure that I wouldn't destroy any data on them. The new (not new,
but rather old..) disk is a small 1.6GB IDE drive.
I did a minimal workstation install without any X-components etc.. And the
system booted absolutely cleanly without a hitch.
I've double checked the disks that normally runs in the system several times
and there's nothing wron at all with them..
Now I've got the same problem again... And during the boot I managed to call
up the traces you've asked for (and I think I've a clue myself now..).
Therefor, I should tell you that on the primary master IDE drive are the
following partitions: /, /boot, /var, /tmp
The primary IDE slave is the CD-ROM.
Secondary IDE master has the /usr partition and the swap partition.
Secondary IDE slave contains the /home partition.
So, when the computer starts up, I get the following:
Checkinf root file system
modprobe: modprobe: Can't locate module block-major-20
/: clean, 17485/98784 files, 69871/395136 blocks
Remounting root filesystem in read-write mode: _ (blinking cursor)
Then I hit alt-sysrq-p and gets this:
Pid: 0, comm: swapper
EIP:0010:[<c0106e03>] CPU: 0
EIP is at default_idle [kernel] 0x23 (2.4.18-3)
EFLAGS: 00000246 Not tainted
EAX: 00000000 EBX: c02e4000 ECX: 00000032 EDX: c0106de0
ESI: c0106de0 EDI: c1050000 EBP: 0008e000 DS: 0018 ES: 0018
CR0: 8005003b CR2: 080501b6 CR3: 0fc52000 CR4: 000002d0
Call Trace: [<c0106e54>] cpu_idle [kernel] 0x24
Then I hit alt-sysrq-t and gets this:
mount D c02c4000 2644 179 178 (NOTLB)
Call Trace: [<cc012a65c>] ___waiting_on_page [kernel] 0x394
[<c012b034>] do_generic_file_read [kernel] 0x394
[<c0140af5>] blkdev_open [kernel] 0x25
[<c012b4ee>] generic_file_read [kernel] 0x7e
[<c012b390>] file_read_actor [kernel] 0x0
[<c013a486>] sys_read [kernel] 0x96
[<c013a3dc>] sys_llseek [kernel] 0xcc
[<c0108913>] system_call [kernel] 0x33
So, my simple conclusion is that it's the swap partition that's the problem?
I'll try to install it again, now with the swap on the same volume as the
system, just to try it out.
Problem is solved.. Although RedHat 7.2 and the e2fs routines shipped in the
package detected any errors at all on any of my disks, there WAS an invalid
partition table on the secondary slave IDE disk!
I didn't include that disk at all in the new installation, I told disk druid
to only use hda for install, but when restarting the system after install, it
failed, there was no mount points defined in the partition, and it wasn't
included at all in fstab.
This caused the hang I guess, but it still seems odd, since that disk WITH its
partitions has worked flawlessly for me in well over a year... Anyways,
deleting the partition and setting up a new one solved the problem.
Now everything works just fine!