2001-03-27 06:49:22

by Thomas Foerster

[permalink] [raw]
Subject: URGENT : System hands on "Freeing unused kernel memory: "

Hello folks,

i have a realy strange and annyoing problem here.

I have a very busy webserver. Around 2 weeks ago i upgraded from 2.2.18 to 2.4.2-ac20
(SCSI-System, 512 MB RAM, 3 SCSI-Disks, P-III-500). Everything worked fine, the 2.4x Kernel
boosted the box a lot :)

But suddenly the box was offline. One technical assistant from our ISP tried to reboot
our server (he couldn't tell me if there had been any messages on the screen), but the
system always hangs on

Freeing unused kernel memory: xxk freed

So we took the box home and tried to boot it from a bootdisk (generated as we installed the box,
redhat 7.0). The SAME problem occurs ...

Freeing unused kernel memory: xxk freed

The system hangs (i've tried 2.2.18 AND 2.4.2-ac20, 2.2.16 is on our bootdisk). I thought
it could be the swap-partition ... so we inserted an IDE Disk, installed a small system so that
i was able to mount the SCSI-Disks. So i rebuild the swap-parition with
mkswap /dev/sda5 and activated it via swapon /dev/sda5 ... worked.

So i tried to boot it again from the SCSI-Disks ... nothing! The same odd failure ...

I've never hat such Problems before .. we've already changed every piece of hardware that's been in the
box (except the disks, but theire looking ok because i can mount them and run e2fsck over it :) )

I need help, because we're already down for 3 Days now. What causes the system to hang at this point??
What must i do the be able to boot the system from the scsi-disks again?

Thanx a lot,
Thomas


2001-03-27 07:51:13

by J.A. Magallon

[permalink] [raw]
Subject: Re: URGENT : System hands on "Freeing unused kernel memory: "


On 03.27 Thomas Foerster wrote:
>
> But suddenly the box was offline. One technical assistant from our ISP tried
> to reboot
> our server (he couldn't tell me if there had been any messages on the screen),
> but the
> system always hangs on
>
> Freeing unused kernel memory: xxk freed
>

Try booting with init=/bin/bash, it looks like kernel gets a bad /sbin/init,
and gets stuck. Perhaps the shutdown damaged init, it starts to run and get
hung.

--
J.A. Magallon # Let the source
mailto:[email protected] # be with you, Luke...

Linux werewolf 2.4.2-ac25 #5 SMP Mon Mar 26 17:46:56 CEST 2001 i686

2001-03-27 08:41:15

by Thomas Foerster

[permalink] [raw]
Subject: Re: URGENT : System hands on "Freeing unused kernel memory: "


> On 03.27 Thomas Foerster wrote:
>>
>> But suddenly the box was offline. One technical assistant from our ISP tried
>> to reboot
>> our server (he couldn't tell me if there had been any messages on the screen),
>> but the
>> system always hangs on
>>
>> Freeing unused kernel memory: xxk freed
>>

> Try booting with init=/bin/bash, it looks like kernel gets a bad /sbin/init,
> and gets stuck. Perhaps the shutdown damaged init, it starts to run and get
> hung.

That didn't fix the problem :(

When i run "diff" on a new and the "old" init, i get no diffs ...

Must be something other :(

Thomas

2001-03-27 09:13:21

by Shmuel Hen

[permalink] [raw]
Subject: RE: URGENT : System hands on "Freeing unused kernel memory: "

Does it hang forever ?

I've noticed that my kernel (2.4.2) stalls for several minutes with the same
message but suddenly after that the login prompt appears (anything between,
like configurations and services starting messages, are gone). We've been
able to track it down to a change we did to /etc/lilo.conf to add support
for kernel prints to go out to a serial debugger. Before that everything was
OK, but after we added append="console=tty0 console=ttyS1,38400", this
problem started. We did notice however that everything that doesn't appear
on the console does appear on the serial debugger.


Shmulik.

-----Original Message-----
From: Thomas Foerster [mailto:[email protected]]
Sent: Tuesday, March 27, 2001 10:40 AM
To: [email protected]
Subject: Re: URGENT : System hands on "Freeing unused kernel memory: "



> On 03.27 Thomas Foerster wrote:
>>
>> But suddenly the box was offline. One technical assistant from our ISP
tried
>> to reboot
>> our server (he couldn't tell me if there had been any messages on the
screen),
>> but the
>> system always hangs on
>>
>> Freeing unused kernel memory: xxk freed
>>

> Try booting with init=/bin/bash, it looks like kernel gets a bad
/sbin/init,
> and gets stuck. Perhaps the shutdown damaged init, it starts to run and
get
> hung.

That didn't fix the problem :(

When i run "diff" on a new and the "old" init, i get no diffs ...

Must be something other :(

Thomas

Subject: Re: URGENT : System hands on "Freeing unused kernel memory: "

I have 2 ideas:
* glibc corrupted
* did you downgrade the cpu?

RH 7.0 automatically installs glibc for a Pentium Pro or later if that
cpu is present during install.
If you then move the hd into a computer with an AMD K6, it won't boot.

I'd run

#rpm -Va

and check if some unusual files are modified (...5.. without "c")

--
Manfred

2001-03-27 09:24:11

by Thomas Foerster

[permalink] [raw]
Subject: RE: URGENT : System hands on "Freeing unused kernel memory: "

> Does it hang forever ?

Yes :(

> I've noticed that my kernel (2.4.2) stalls for several minutes with the same
> message but suddenly after that the login prompt appears (anything between,
> like configurations and services starting messages, are gone). We've been
> able to track it down to a change we did to /etc/lilo.conf to add support
> for kernel prints to go out to a serial debugger. Before that everything was
> OK, but after we added append="console=tty0 console=ttyS1,38400", this
> problem started. We did notice however that everything that doesn't appear
> on the console does appear on the serial debugger.

We didn't change anything on the system .. it once crashed and now it won't boot
anymore, it always stops at "freeing unused kernel memory ..."

Thomas

2001-03-27 10:08:13

by Giacomo Catenazzi

[permalink] [raw]
Subject: Re: URGENT : System hands on "Freeing unused kernel memory: "

Studierende der Universitaet des Saarlandes wrote:
>
> I have 2 ideas:
> * glibc corrupted
> * did you downgrade the cpu?

These happen frequently to me (when compiling and installing a
new glibc)
But in this case you would have other messages (IIRC something
like
respawn too fast).
Thus the problem is not this!


Possible problem:

1) permition of /sbin/init
2) unable to exec ELF binary (or a.out, which init do you
have?)
3) problems with the root partition. (check it with an
emergency disk)
4) once I had strange problem with init and /dev (init was
continuosly
killed, but after some init.d scripts). Check your /dev/


giacomo

2001-03-27 11:22:02

by Jonathan Morton

[permalink] [raw]
Subject: Re: URGENT : System hands on "Freeing unused kernel memory: "

>> I have 2 ideas:
>> * glibc corrupted
>> * did you downgrade the cpu?
>
>These happen frequently to me (when compiling and installing a
>new glibc)
>But in this case you would have other messages (IIRC something
>like
>respawn too fast).
>Thus the problem is not this!

How about running memtest86 - could be that a RAM module blew up or worked
loose and caused the initial crash and this misbehaviour both at once.

--------------------------------------------------------------
from: Jonathan "Chromatix" Morton
mail: [email protected] (not for attachments)
big-mail: [email protected]
uni-mail: [email protected]

The key to knowledge is not to rely on people to teach you it.

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2001-03-27 14:38:13

by Stuart MacDonald

[permalink] [raw]
Subject: Re: URGENT : System hands on "Freeing unused kernel memory: "

From: "Thomas Foerster" <[email protected]>
> But suddenly the box was offline. One technical assistant from our ISP
tried to reboot
> our server (he couldn't tell me if there had been any messages on the
screen), but the
> system always hangs on
>
> Freeing unused kernel memory: xxk freed

I have a customer with the same symptom. They
have stock Mandrake 7.2 (kernel 2.2.17-21mdk)
and have installed serial-5.05 into it. The kernel
boots to the Freeing message and hangs. I
noticed ctl-alt-del still works, so I configured in
magic sysrq (Documentation/sysrq.txt). sysrq-p
allowed me to get the eip, which checking against
the System.map I find is mod_timer(). A quick
printk showed me that the kernel isn't hung,
it's in an infinite loop, with mod_timer() being
one of the calls in the loop.

YMMV, but hopefully this method can help
you find your problem.

..Stu


2001-03-27 16:20:13

by Alan

[permalink] [raw]
Subject: Re: URGENT : System hands on "Freeing unused kernel memory: "

> Freeing unused kernel memory: xxk freed
>
> So we took the box home and tried to boot it from a bootdisk (generated as we installed the box,
> redhat 7.0). The SAME problem occurs ...
>
> Freeing unused kernel memory: xxk freed
>
> The system hangs (i've tried 2.2.18 AND 2.4.2-ac20, 2.2.16 is on our bootdisk). I thought
> it could be the swap-partition ... so we inserted an IDE Disk, installed a small system so that
> i was able to mount the SCSI-Disks. So i rebuild the swap-parition with
> mkswap /dev/sda5 and activated it via swapon /dev/sda5 ... worked.
>
> So i tried to boot it again from the SCSI-Disks ... nothing! The same odd failure ...

Boot off the ide disk and fsck the scsi disks. See if that helps