Difference between revisions of "Fs-drbd"

__NOTOC__

= DRBD =

== How to setup DRBD with separated resource and meta-disk ==

'''On both servers'''

# Create 2 separate partitions on each server, one for meta and one for data. Some meta-disk size approximations:

||'''Block device size'''||'''DRBD meta data'''||

|| 1 GB || 2 MB ||

|| 100 GB || 4+1 MB ||

|| 500 GB || 16+2 MB ||

|| 1 TB || 32+2 MB ||

|| 2 TB || 64+1 MB ||

|| 4 TB || 128 MB ||

# If the meta-disk and resource partition are listed on fstab, then remove them from there

# Install drbd

<pre><nowiki>

# apt-get -y install drbd8-utils

</nowiki></pre>

# Edit `drbd.conf` to something similar to:

<pre><nowiki>

global { usage-count no; }

common { syncer { rate 100M; } }

resource srv {

protocol C;

startup {

wfc-timeout 15;

degr-wfc-timeout 60;

}

net {

cram-hmac-alg sha1;

shared-secret "B1ng0!";

}

on SERVER-01p {

device /dev/drbd0;

disk /dev/md4;

address IP_SERVER-01p:7788;

meta-disk /dev/md3[0];

}

on SERVER-01s {

device /dev/drbd0;

disk /dev/md4;

address IP_SERVER-01s:7788;

meta-disk /dev/md3[0];

}

}

</nowiki></pre>

# Create resource and meta-disk

<pre><nowiki>

# drbdadm create-md srv

</nowiki></pre>

# Start DRBD

<pre><nowiki>

# service drbd start

</nowiki></pre>

'''On primary server'''

When finish the previous setup on both servers

# Tell DRBD which one is the primary

<pre><nowiki>

# drbdadm -- --overwrite-data-of-peer primary all

</nowiki></pre>

This going to take a long, depending of the size of the drive. The sync can be watched at `/proc/drbd` file.

# When drbd sync is done, then, create the filesystem on drbd device

<pre><nowiki>

# mkfs.ext4 /dev/drbd0

</nowiki></pre>

# Finally, mount drbd device on the primary server

<pre><nowiki>

# mount /dev/drbd0 /srv

</nowiki></pre>