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Bad magic number for tty struct

Michael BUTOW
Frequent Advisor

Bad magic number for tty struct

Hello all,

I have experienced a crash (complete freeze, no mouse movement possible, not network connectivity) on a Proliant DL380/G4 running RHEL 3ES U4.

The machine was powered off and on again and came up again.
The system log showed that for about 4 minutes prior to the freeze, there were error messages as follows:

Jun 23 08:52:59 BSMS1 kernel: Warning: bad magic number for tty struct (05:02) in tty_write
Jun 23 08:52:59 BSMS1 kernel: Warning: bad magic number for tty struct (05:02) in tty_poll

I would like to know what could cause this and how to fix it - does anyone have some ideas?

Best regards,
Michael

P.S. In case it is relevant, the machine has network connection via bonding on two Intel Pro/1000 NICs.
3 REPLIES
Steven E. Protter
Exalted Contributor

Re: Bad magic number for tty struct

Temporay tty files are probably written to /var

Is there anything about /var being full, or not mounted properly at boot? That is one possible trigger for what went on.

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Steven E Protter
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Michael BUTOW
Frequent Advisor

Re: Bad magic number for tty struct

Hello Steven,

/var is located in root filesystem which is only 62% full, with 300MB free.

What could be the other reasons?

Michael
Gopi Sekar
Honored Contributor

Re: Bad magic number for tty struct


I don't know about the reason for the error message. But few things which can be reason for machine freezing: RAM, Bad chip, a process running takes full CPU and freezes

Check the RAM: use memtest86 utility which is free and open source.

If this does not yield any results check your process usage from the system statistics (SAR utility)

If nothing yields good result and you continue to face the machine freezing problem then call up support people for hardware check.

Hope this helps,
Gopi
Never Never Never Giveup