Re: I killed my system with grep
Loren M. Lang wrote:
On Fri, Feb 25, 2005 at 11:42:48PM -0500, Parv wrote:
in message [EMAIL PROTECTED],
wrote Loren M. Lang thusly...
On Fri, Feb 25, 2005 at 12:14:04PM +0100, Ramiro Aceves wrote:
I am running a FreeBSD 5.3 system with 64MB RAM and 150 MB swap.
Yesterday I entered the command:
# grep -R something /
You probably hit a file under /dev/ and caused grep to hang. It's
possible that as root, certain device files might hang the system,
but nothing comes to mind at the moment unless /dev/io could do
it. Also, think about what happens when grep hit's /dev/zero. It
will never finish.
Would using -I option (not search text-like files) help to avoid
above described hang ups in /dev?
No, it still searches all files, it just doesn't print the usual line
that it matched, only whether there was success or not. You really just
need to make sure grep never goes into /dev. Since your running 5.x,
/dev is it's own filesystem of a unique type, so the following command
will run grep on only filesystems of type ufs, which won't include
network filesystems, or /dev:
find / -fstype ufs -exec grep -H something {} \;
- Parv
--
Many thanks for the valuable info!
I will never grep into /dev
Ramiro.
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Re: I killed my system with grep
Ramiro Aceves wrote: Hello FreeBSD friends: I am running a FreeBSD 5.3 system with 64MB RAM and 150 MB swap. Yesterday I entered the command: # grep -R something / and after a while, my system did not respond. I do not remember the exact messages as I am on a winbugs at the University. The error was about swapping. I could switch among terminals but the system was dead. I needed to reboot. I rebooted and tried again watching top output and I could see as swap usage was incresing very quickly until it ran out of swap space and the swap pager failed. Was my sytem dead? or, is it possible to recover from that state without rebooting? How is it possible that a simple command like this could auto-kill the machine? What is the recomended fix for this?: a- Asigning more swap. b- Not executing that command anymore. Thank you very much for your advices and help. Ramiro Thanks all for your responses. I understand that I should avoid greping into /dev. I will do more accurate searchs into the directories. Ramiro. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: I killed my system with grep
On Fri, Feb 25, 2005 at 11:42:48PM -0500, Parv wrote:
in message [EMAIL PROTECTED],
wrote Loren M. Lang thusly...
On Fri, Feb 25, 2005 at 12:14:04PM +0100, Ramiro Aceves wrote:
I am running a FreeBSD 5.3 system with 64MB RAM and 150 MB swap.
Yesterday I entered the command:
# grep -R something /
You probably hit a file under /dev/ and caused grep to hang. It's
possible that as root, certain device files might hang the system,
but nothing comes to mind at the moment unless /dev/io could do
it. Also, think about what happens when grep hit's /dev/zero. It
will never finish.
Would using -I option (not search text-like files) help to avoid
above described hang ups in /dev?
No, it still searches all files, it just doesn't print the usual line
that it matched, only whether there was success or not. You really just
need to make sure grep never goes into /dev. Since your running 5.x,
/dev is it's own filesystem of a unique type, so the following command
will run grep on only filesystems of type ufs, which won't include
network filesystems, or /dev:
find / -fstype ufs -exec grep -H something {} \;
- Parv
--
--
I sense much NT in you.
NT leads to Bluescreen.
Bluescreen leads to downtime.
Downtime leads to suffering.
NT is the path to the darkside.
Powerful Unix is.
Public Key: ftp://ftp.tallye.com/pub/lorenl_pubkey.asc
Fingerprint: B3B9 D669 69C9 09EC 1BCD 835A FAF3 7A46 E4A3 280C
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I killed my system with grep
Hello FreeBSD friends: I am running a FreeBSD 5.3 system with 64MB RAM and 150 MB swap. Yesterday I entered the command: # grep -R something / and after a while, my system did not respond. I do not remember the exact messages as I am on a winbugs at the University. The error was about swapping. I could switch among terminals but the system was dead. I needed to reboot. I rebooted and tried again watching top output and I could see as swap usage was incresing very quickly until it ran out of swap space and the swap pager failed. Was my sytem dead? or, is it possible to recover from that state without rebooting? How is it possible that a simple command like this could auto-kill the machine? What is the recomended fix for this?: a- Asigning more swap. b- Not executing that command anymore. Thank you very much for your advices and help. Ramiro ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: I killed my system with grep
On Fri, Feb 25, 2005 at 12:14:04PM +0100, Ramiro Aceves wrote: Hello FreeBSD friends: I am running a FreeBSD 5.3 system with 64MB RAM and 150 MB swap. Yesterday I entered the command: # grep -R something / Running a grep on an entire system as root is a bad idea. At least limit to certain filesystems. You probably hit a file under /dev/ and caused grep to hang. It's possible that as root, certain device files might hang the system, but nothing comes to mind at the moment unless /dev/io could do it. Also, think about what happens when grep hit's /dev/zero. It will never finish. and after a while, my system did not respond. I do not remember the exact messages as I am on a winbugs at the University. The error was about swapping. I could switch among terminals but the system was dead. I needed to reboot. I rebooted and tried again watching top output and I could see as swap usage was incresing very quickly until it ran out of swap space and the swap pager failed. Was my sytem dead? or, is it possible to recover from that state without rebooting? How is it possible that a simple command like this could auto-kill the machine? What is the recomended fix for this?: a- Asigning more swap. b- Not executing that command anymore. Thank you very much for your advices and help. Ramiro ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED] -- I sense much NT in you. NT leads to Bluescreen. Bluescreen leads to downtime. Downtime leads to suffering. NT is the path to the darkside. Powerful Unix is. Public Key: ftp://ftp.tallye.com/pub/lorenl_pubkey.asc Fingerprint: B3B9 D669 69C9 09EC 1BCD 835A FAF3 7A46 E4A3 280C ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: I killed my system with grep
Ramiro Aceves [EMAIL PROTECTED] writes: Hello FreeBSD friends: I am running a FreeBSD 5.3 system with 64MB RAM and 150 MB swap. Yesterday I entered the command: # grep -R something / and after a while, my system did not respond. I do not remember the exact messages as I am on a winbugs at the University. The error was about swapping. I could switch among terminals but the system was dead. I needed to reboot. I rebooted and tried again watching top output and I could see as swap usage was incresing very quickly until it ran out of swap space and the swap pager failed. Was my sytem dead? or, is it possible to recover from that state without rebooting? How is it possible that a simple command like this could auto-kill the machine? What is the recomended fix for this?: a- Asigning more swap. b- Not executing that command anymore. c- Setting user limits in login.conf(5). ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: I killed my system with grep
in message [EMAIL PROTECTED], wrote Loren M. Lang thusly... On Fri, Feb 25, 2005 at 12:14:04PM +0100, Ramiro Aceves wrote: I am running a FreeBSD 5.3 system with 64MB RAM and 150 MB swap. Yesterday I entered the command: # grep -R something / You probably hit a file under /dev/ and caused grep to hang. It's possible that as root, certain device files might hang the system, but nothing comes to mind at the moment unless /dev/io could do it. Also, think about what happens when grep hit's /dev/zero. It will never finish. Would using -I option (not search text-like files) help to avoid above described hang ups in /dev? - Parv -- ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
Re: I killed my system with grep
On Fri, 25 Feb 2005 12:14:04 +0100, Ramiro Aceves wrote Hello FreeBSD friends: I am running a FreeBSD 5.3 system with 64MB RAM and 150 MB swap. Yesterday I entered the command: # grep -R something / and after a while, my system did not respond. I do not remember the exact messages as I am on a winbugs at the University. The error was about swapping. I could switch among terminals but the system was dead. I needed to reboot. I rebooted and tried again watching top output and I could see as swap usage was incresing very quickly until it ran out of swap space and the swap pager failed. Was my sytem dead? or, is it possible to recover from that state without rebooting? How is it possible that a simple command like this could auto-kill the machine? What is the recomended fix for this?: a- Asigning more swap. b- Not executing that command anymore. I had a very similar problem. I fixed it by reading up on auxillary swapfile. I set one of those up as indicated, at about 2.5x RAM (750MB, roughly) and the problem went away after I edited /etc/fstab and commented out the old swap entry, then rebooted. The problem was caused by the hard drive having failing blocks where the swap partition resides. I got a few errors in /var/log/messages where the swap daemon couldnt zero pages or inodes or whatever. If the swapper cant liberate old pages then swap will fill up. My machine uses a lot of perl, and openwebmail makes it swap under load. It seems that the bad blocks are only on the old swap so hopefully the hard drive still has some life in it yet. -- [EMAIL PROTECTED] ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to [EMAIL PROTECTED]
