[Linux-cluster] gfs mounted but not working

[Riaan van Niekerk]

Robert Peterson wrote:
> romero.cl at gmail.com wrote:
>> Hello.
>>  
>> I have a two node cluster runing.
>>  
>> Each one have /dev/sdb2 mounted as gfs on /users/home, but when I 
>> create one file y node1 not appear on node2.
>>  
>> I use the following commands to create the file systems:
>>  
>> on node1: gfs_mkfs -p lock_dlm -t node1_cluster:node1_gfs -j 8 /dev/sdb2
>> on node2: gfs_mkfs -p lock_dlm -t node1_cluster:node1_gfs -j 8 /dev/sdb2
>>  
>> What I'm doing wrong?
> Hi,
> 
> When using GFS in a clustered environment, I strongly recommend you use LVM
> rather than using the raw device for your GFS partition.  Without a 
> clustered
> LVM of some sort, there is no locking coordination between the nodes.
> I'm assuming, of course, that device sdb is some kind of shared storage, 
> like a SAN.
> 
> For example, assuming that your /dev/sdb2 has no valuable data yet, I 
> recommend
> doing something like this:
> 
> pvcreate /dev/sdb2
> vgcreate your_vg /dev/sdb2  (where "your_vg" is the name you choose for 
> your new vg)
> vgchange -cy your_vg (turn on the clustered bit)
> lvcreate -n your_lv -L 500G your_vg (where 500G is the size of your file 
> system,
>                and your_lv is the name you choose for your lv)
> gfs_mkfs -p lock_dlm -t node1_cluster:node1_gfs -j 8 /dev/your_vg/your_lv
> (on only one node)
> At this point you've got to bring up the cluster infrastructure, if it 
> isn't already up.
> Next, mount the logical volume from both nodes:
> mount -tgfs /dev/your_vg/your_lv /users/home
> 
> Now when you touch a file on one node, the other node should see it.
> 
> I hope this helps.
> 
> Regards,
> 
> Bob Peterson
> Red Hat Cluster Suite
> 


Romero - you should only gfs_mkfs from one node, and the other should 
pick it up. Also (some may feel it goes without saying) you need shared 
storage between these nodes - GFS does not replicate data between nodes)

Bob - as far as I understand, LVM has certain advantages over native 
devices (dont have to worry about device names, easy expandability of 
LVs vs partitions). however there are people who are running GFS without 
clvmd, which is technically not wrong. (they do so to keep things simple 
- one less thing that can break).

just switching from GFS on top of partitions to GFS on top of a LVM 
should not solve such a problem as described by Romero (assuming 
everything else is working and properly configured)

HTH
Riaan
-------------- next part --------------
A non-text attachment was scrubbed...
Name: riaan.vcf
Type: text/x-vcard
Size: 310 bytes
Desc: not available
URL: <http://listman.redhat.com/archives/linux-cluster/attachments/20061104/ed0a8eb5/attachment.vcf>