[DRBD-user] 0.6.x to 0.7.0 upgrade questions

Stefan Andersson kollen_79 at nosplease.com
Tue Aug 3 22:30:40 CEST 2004


Hello,

I read the
http://svn.drbd.org/drbd/tags/drbd-0.7.1/upgrade_0.6.x_to_0.7.0.txt
and have some questions:


>  In order to do this upgrade you either need to
>
>   A) shrink your filesystems on the DRBD devices by at least 128MB, or
>   B) grow the backing_storage of the DRBD devices by at least 128MB, or
>   C) have one separate block_device for all meta data
>
>  A)
>  ext2/ext3   resize2fs
>  reiserfs    resize_reiserfs     
>  xfs         xfsdump, xfsrestore ; xfs can only grow
>
>  B)
>  lvresize    in case you run DRBD on LVM
>  (fdisk)     (Only do this if you know what you are doing.)
>
>  C)
>  The size of the meta-data device needs to be at least n*128MB,
>  where n is the number of DRBD resources you want to use.


I use drbd on top of a lvm volume. From the description, I assume that
the meta-data is stored at the end of the block device, as storing it at
the beginning would both wreck the existing filesystem and be
overwritten by mkfs.

So, if I lvresize my logical volume to hold the metadata and upgrade to
0.7.x, what will happen if I would like a bigger filesystem?
Assume that I have a 50GB filesystem now running 0.6.x. I expand this
with 128MB to hold the metadata, and upgrade to 0.7.x.

Later, I increase the size to 70.128GB on both machines, update drbd.conf
to reflect the new size, resize2fs. This means the old metadata is
overwritten by the filesystem. Does drbd handle this and recreate the
metadata in the last 128MB of the resized logical volume.

How is this place determined? Seek to the end of the device minus 128MB?

Is there any check being done to assure that it is not occupied by a
filesystem?

Regards,
 Stefan



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