[ENBD] enbd + fr1 question/explanation

[Ste]

Peter T. Breuer wrote:
> Which kernel? And driver versions? (if known).
kernel 2.4.31
fr1 2.17



>> So the fr1 module is syncing the two components of the array.
>
> Are you sure that is fr1? What is the evidence that tells you so? (I
> don't recall the output format, but I'm pretty sure it's close to
> identical to raid1).
>
I think that fr1 is used:
root at data:~# lsmod
Module                  Size  Used by    Not tainted
...
fr1                    16784   1
md                     48960   1  [fr1]
bitmap                  4976   0  [fr1]
...


So i think that the fr1 module is used.

There is a better way to know if it is used? Or can someone tell me a 
kernel version on wich the fr1 worked without any problem?

I followed the instructions: first i created a raid 1 with the superblock.
So /dev/md0 is okay. When i crate the raid the first time there is a 
"resync".
However this resync can be bypassed with --dangerous-no-resync option. 
So one problem could be solved.

Now, when i start the raid with "raidstart" now there is not a resync. 
This is okay.

But, if one of the disk goes offline, there is a total "recovery" 
instead the recovery of the last changed blocks.

I followed these instructions taken from the fr1 README:

 "On a mirror with a persistent superblock, you have to go the whole
  raidsetfaulty, raidhotremove, raidhotadd rigmarole, but if you add
  back in an old disk, it will be recognized, and the "hotrepair" 
  will take place nevertheless."


But it seems to don't work:


root at data:/mnt# cat /proc/mdstat
Personalities : [raid1]
read_ahead 1024 sectors
md0 : active raid1 nda[2] ndb[1]
      104320 blocks [2/1] [_U]
      [>....................]  recovery =  0.0% (828/104320) 
finish=116.9min speed=13K/sec


Thanks,
Stefano.