[Linux-cluster] GFS and Storage greater than 2 TB

[Markus Miller]

Thank you for the answer. That is all I needed to know.

-----Mensaje original-----
De: Rick Stevens [mailto:rstevens at vitalstream.com]
Enviado el: Thursday, December 30, 2004 5:03 PM
Para: linux clistering
Asunto: Re: [Linux-cluster] GFS and Storage greater than 2 TB


Markus Miller wrote:
> Hi,
> 
> researching I found a posting to this list made by Kevin Anderson (Date: Tue, 19 Oct 2004 17:56:24 -0500) where he states the following:
> 
> ---snip---
> Maximum size of each GFS filesystem for RHEL3 (2.4.x kernel) is 2 TB,
> you can have multiple filesystems of that level.  So, to get access to
> 10TB of data requires a minimum of 5 separate filesystems/storage
> combinations.
> ---snip---
> 
> What do I have to do to achive this? Do I have to configure several GFS clusters in the cluster.ccs file (each of a máximum size of 2 TB)? Or do I have to configure one GFS cluster with serveral filesystems each with a maximum size of 2 TB? The GFS Admin Guide is not very precise, but what's really confusing me is the statement on page 12: "2 TB maximum, for total of all storage connected to a GFS cluster."
> 
> At the moment we are evaluating to buy servers and storage, therefore I do not have any equipment to do the testing myself. 
> 
> Any coment is highly apreciated.

It's the GFS filesystem that has the limit (actually, it's the 2.4
kernel).  Essentially, "gfs_mkfs" can only handle a maximum of 2TB.

What he means above is that you have to have five separate partitions
of 2TB each and each with a GFS filesystem on them.  You have to mount
those five filesystems separately.  If you're using VG/LVM, with a VG
as "vggroup" and LVs in that group as "test1" through "test5":

	mount -t gfs /dev/mapper/vggroup-test1 /mnt/gfs1
	mount -t gfs /dev/mapper/vggroup-test2 /mnt/gfs2
	mount -t gfs /dev/mapper/vggroup-test3 /mnt/gfs3
	mount -t gfs /dev/mapper/vggroup-test4 /mnt/gfs4
	mount -t gfs /dev/mapper/vggroup-test5 /mnt/gfs5

How you use them after that is up to you.  Just remember that a given
GFS filesystem under kernel 2.4 is limited to 2TB maximum
----------------------------------------------------------------------
- Rick Stevens, Senior Systems Engineer     rstevens at vitalstream.com -
- VitalStream, Inc.                       http://www.vitalstream.com -
-                                                                    -
-        Brain:  The organ with which we think that we think.        -
----------------------------------------------------------------------

--
Linux-cluster mailing list
Linux-cluster at redhat.com
http://www.redhat.com/mailman/listinfo/linux-cluster