[Gluster-users] GlusteFS VS DRBD + power failure ?

[Daniel Müller]

For sure power failure on both nodes will corrupt drbd as well. Power failure in a clusterd datacenter is the worst case and point of failure.


EDV Daniel Müller

Leitung EDV
Tropenklinik Paul-Lechler-Krankenhaus
Paul-Lechler-Str. 24
72076 Tübingen 
Tel.: 07071/206-463, Fax: 07071/206-499
eMail: mueller at tropenklinik.de
Internet: www.tropenklinik.de 



Von: gluster-users-bounces at gluster.org [mailto:gluster-users-bounces at gluster.org] Im Auftrag von Tytus Rogalewski
Gesendet: Montag, 27. Oktober 2014 21:35
An: gluster-users at gluster.org
Betreff: Re: [Gluster-users] GlusteFS VS DRBD + power failure ?

Hi guys,
I wanted to ask you about what happen in case of power failure.
I have 2 node proxmox cluster with glusterfs as sdb1 XFS, and mounted on each node as localhost/glusterstorage.
I am storing VMs on it as qcow2(and inside ext4 filesystem).
 Live migration works ok WOW.. Everything works fine.
But tell me will something bad happen when the power will fail on whole datacenter ?
Will be data corrupted and will be the same thing if i am using drbd ?
DRBD doesnt give me so much flexability(because i cant use qcow2 and store files like iso or backups on drbd), but glusterfs does give me much flexability !
Anyway yesterday i created glusterfs with ext4, and VM qcow with ext4 on it and when i made "reboot -f"(i assume this is the same as i will pull power cord off ?) - after node went online again, VM data was corrupted and i had many ext failures inside VM.
Tell me was that because i used ext4 on top of sdb1 glusterfs storage or will that work the same with XFS ?
Is drbd better  protection in case of power failure ?

Anyway second question, if i have 2 nodes with glusterfs.
node1 is changing file1.txt
node2 is changing file2.txt
then i will disconnect glusterfs in network, and data keeps changing on both nodes)
After i will reconnect glusterfs how this will go?
Newer changed file1 from node1 will overwrite file1 on node2?
and newer file2 changed on node2 will overwrite file2 on node1 ?
Am i correct ?

Thx for answer :)