gmirror magic ?

[Frans Haarman]

Excuse my ignorance,

What I tried was removing a file on disk which 
was  attached as a "md vnode". 

I assumed removing the file on disk will "kill" 
the "md vnode" but it does not.

It seems this has nothing todo with gmirror/gstripe
but the way md vnodes work!




Frans Haarman 
De Giessen Automatisering B.V.



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d u i d e l i j k e   t a a l !


-----Oorspronkelijk bericht----- 
Van: Eric Anderson [mailto:anderson at freebsd.org] 
Verzonden: dinsdag 1 mei 2007 15:03
Aan: Frans Haarman
CC: freebsd-geom at freebsd.org
Onderwerp: Re: gmirror magic ?

On 05/01/07 07:24, Frans Haarman wrote:
> Can someone explain this to me ? I was testing gmirror/gstripe and 
> decided to remove the vnode files stripe0 & stripe1. This resulted in 
> a mirror which kept on working.....
>  
>  
> /dev/mirror/mirro0 on /mnt (ufs, local)
>  
> DEVEL# ls /mnt/
> .snap   anders  test    testje
> 
> DEVEL# ls /data/STRIPING/
> create-image-file       mnt                     mnt0
> mnt1
> 
> 
> DEVEL# mdconfig -l -u md1
> md1     vnode     512M  /data/STRIPING/stripe0
> DEVEL# mdconfig -l -u md2
> md2     vnode     512M  /data/STRIPING/stripe1
> DEVEL# mdconfig -l -u md123
> md123   vnode     512M  /data/STRIPING/stripe1


Does that look right to you?  You have 2 md devices using the same file?

> DEVEL# gmirror status
>          Name    Status  Components
> mirror/mirro0  COMPLETE  md2
>                          md123

Where exactly does the gstripe come in?


> DEVEL# dd if=/dev/zero of=where-does-this-go bs=1m count=512

I'm assuming your cwd was /mnt?


> /mnt: write failed, filesystem is full
> dd: where-does-this-go: No space left on device
> 431+0 records in
> 430+0 records out
> 450887680 bytes transferred in 67.178881 secs (6711747 bytes/sec) 
> DEVEL#

Ok - looks about right to me.  You had a 512M mirror, and you wrote
enough to fill the file system up.. ?  Right?

> This seems quite strange to me :) Its probably the way vnode disks are

> attached to the filesystem ?


I'm missing something.  You might try to paint a bit clearer picture, as
it's pretty hard to understand what exactly we should be looking for..

Eric