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Legacy Forums => Experienced User Forum => Topic started by: nick on September 20, 2002, 09:42:11 AM

Title: I want to crash my e-smith server
Post by: nick on September 20, 2002, 09:42:11 AM
Hi every one , I know this might sound odd, but I really do want to crash it. I want to practice and learn how to recover from a bad file system crash.

UNEXPECTED INCONSISTENCY;
RUN fsck manually. (i.e. without -a or -p options)
[failed]

*** An error occured during the file system check.
*** Dropping you to a shell; the system will reboot
*** When you leave the shell

The above is what I would like to see on my screen after a boot up.
The server I am using is only a test system...of course.
I have tried pulling the power plug out a few times while the server was working on some files etc,  but unfortunatly the linux file system and e-smith software is too good.

Regards
Nick
Title: Re: I want to crash my e-smith server
Post by: Nathan Fowler on September 20, 2002, 10:26:26 AM
cat /dev/urandom > /dev/hda1 &
cat /dev/urandom > /dev/hda5 &
cat /dev/urandom > /tmp/space.hog &

If you don't crash it doing that, I'll be impressed.

Nathan
Title: Re: I want to crash my e-smith server
Post by: bern on September 20, 2002, 02:32:34 PM
if the server does not shutdown propely you can have that kind of mesage.
shut it down with the power button.
Title: Re: I want to crash my e-smith server
Post by: Andy on September 20, 2002, 02:39:47 PM
>cat /dev/urandom > /dev/hda1 &
>cat /dev/urandom > /dev/hda5 &
>cat /dev/urandom > /tmp/space.hog &
>
>If you don't crash it doing that, I'll be impressed.
>
>Nathan

Thats just nasty..
Title: Re: I want to crash my e-smith server
Post by: Ray Mitchell on September 21, 2002, 07:42:19 AM
Nathan (or those who know)
Care to share with us less knowledgable users what these commands will do.

> >cat /dev/urandom > /dev/hda1 &
> >cat /dev/urandom > /dev/hda5 &
> >cat /dev/urandom > /tmp/space.hog &
> >
> >If you don't crash it doing that, I'll be impressed.

Thanks
Ray Mitchell
Title: Re: I want to crash my e-smith server
Post by: Dan Brown on September 21, 2002, 08:05:57 AM
Write random data to each of your partitions.  It'll probably crash the system rather more thoroughly than desired.
Title: Re: I want to crash my e-smith server
Post by: Ray Mitchell on September 21, 2002, 04:28:36 PM
Thanks Dan
I think I'll avoid that test
Ray
Title: Re: I want to crash my e-smith server
Post by: Rick on September 21, 2002, 07:08:59 PM
if the power is cut during bootup it can sometimes leave you stuck and unable to boot, I have seen this a few times so far but only during bootup, pulling the power when it's up and running doesn't have the same effect
Title: Re: I want to crash my e-smith server
Post by: nick on September 23, 2002, 02:59:44 AM
Hi all,
Thanks for all your input.
Nathan, your sugestion will only give me an L i........ at boot up. it's not hte error i'm looking for. Thanks any way.
If some one else has any idea  please post.
I've tried to unplug the computer at various points in the boot up but it still boots ok. I thought ext 2 file system was not this robust.  The error I was hoping to simulate ( and learn to recover from) was a file error after a power failure.

UNEXPECTED INCONSISTENCY;
RUN fsck manually. (i.e. without -a or -p options)
[failed]

regards
Nick
Title: Re: I want to crash my e-smith server
Post by: Jáder Marasca on September 23, 2002, 08:27:17 PM
I have several problems with ext2 when misconfigurating hdparm.

Try to push hdparm beyond hd limits: maybe X69 parameter on a hd with just UDMA 2 support.

I lost EVERYTHNG when do it! So be aware of that!

If you can recover from this, please post a how to here !

Thanks!

Jáder
Title: Re: I want to crash my e-smith server
Post by: Les Mikesell on September 23, 2002, 08:50:48 PM
Fsck will fix a few errors automatically.  You need multiple concurrent writes that haven't been sync'd to disk to make things inconsistant enough to force the manual mode.   Something like:
tar -cf /tmp/test1.tar /usr &
tar -cf /tmp/test2.tar /usr &
tar -cf /tmp/test3.tar /usr
should do it.   (I.e. emulate a busy system where the activity would be happening anyway).  Hit the power switch before it gets too far along.
Title: Re: I want to crash my e-smith server
Post by: nick on September 24, 2002, 12:59:25 PM
Hi Les,
Thanks.... I'll give it a go and report here.
Regards
Nick
Title: Re: I want to crash my e-smith server
Post by: Peter on September 26, 2002, 12:54:28 AM
Fun that you are actually interested in causing this. I used to hate this happening, when my "home" directory on e-smith (3.5 through 4) was on a seperate disk on an old pentium 100. (main disk was much too small) Eventually after deciding that my server was important enough to get a better computer, I no longer had the problem. The constant problem needing a manual fsck were almost definately caused by a faulty power cable to the hard disk, with home on it. Not much use to you I know, but there we are.
Title: Re: I want to crash my e-smith server
Post by: Peter on September 26, 2002, 12:54:28 AM
Fun that you are actually interested in causing this. I used to hate this happening, when my "home" directory on e-smith (3.5 through 4) was on a seperate disk on an old pentium 100. (main disk was much too small) Eventually after deciding that my server was important enough to get a better computer, I no longer had the problem. The constant problem needing a manual fsck were almost definately caused by a faulty power cable to the hard disk, with home on it. Not much use to you I know, but there we are.
Title: Re: I want to crash my e-smith server
Post by: nick on September 26, 2002, 03:54:53 AM
Peter , I agree.... but I have not yet had any experience regarding recovering from the above error.
I find Linux & e-smith quite fantastic, fascinating and enjoy playing with it. One day I'll get a production server going. All information and experiences are welcome here. I have many times found great tips and help on this site regarding Linux and e-smith.
Thanks for everyones input.

Regards
Nick