[Linux-cluster] partitioning of filesystems in cluster nodes

[Greg Forte]

No, I'm pretty sure what that's saying is that you can't build a GFS 
filesystem _on top of_ a software RAID volume.  (Although you probably 
could, using GNDB ...) but unless I misunderstood you, you're talking 
about non-GFS filesystems on the local hard drives, with GFS on a SAN. 
This is a "standard" configuration, and certainly there's no reason you 
can't use software raid on the disks that will host non-GFS volumes.

-g

RR wrote:
> Hi Greg,
> 
> Thanks for the input. What you say makes sense, but I was getting these
> ideas from places like these: http://kbase.redhat.com/faq/FAQ_78_3105.shtm
> 
> Have I totally misunderstood this? Maybe this is saying the same thing as
> you are but I understand it wrong? I'm definitely not exporting any of my
> local volumes or filesystems to anywhere, all I want to do is have this
> particular directory tree which is based in /var/spool to actually be on the
> SAN and have all nodes read/write to it at their discretion. Nothing too
> complicated. But this FAQ seems to say that if I'm running GFS on my nodes,
> then those nodes cannot be running software RAID. Somewhere else I'd read I
> can't also have LVM volumes on these disks. What I originally had planned
> was to have software raid using md and LVM volumes on each machine to allow
> for RAID and resizing on each node and then have GFS. 
> 
> I'm all confused now! Please clarify someone?
> 
> Thanks, and sorry if this is stupid! :(
> RR
> 
> 
> 
> -----Original Message-----
> From: linux-cluster-bounces at redhat.com
> [mailto:linux-cluster-bounces at redhat.com] On Behalf Of Greg Forte
> Sent: Thursday, June 22, 2006 3:47 PM
> To: linux clustering
> Subject: Re: [Linux-cluster] partitioning of filesystems in cluster nodes
> 
> Where have you gotten these ideas?  LVM and software raid are not mutually
> exclusive with GFS.  Your local disks can easily have LVM volumes and use
> software (or hardware) RAID, no problem.  Unless you're trying to export
> local disks as GFS volumes via GNDB (which I can't speak to, have never done
> that), there shouldn't be any restrictions on how you can configure the
> local disks.  If you want certain portions of the local filesystem(s) to be
> located on the SAN instead, it's as simple as a symlink (as Bob indicated).
> 
> -g
> 
> RR wrote:
>> Thanks Bob, that was my thought as well but just wasn't sure if that 
>> was the best way to implement partitioning. I suppose I'm still a bit 
>> not comfy with GFS considering I've never seen it in action but should 
>> do in a few days time, as I'm starting to set up the cluster suite and GFS
> now.
>> I'm assuming I still cannot use Logical Volumes on the cluster nodes 
>> while the nodes are being used within a cluster in conjunction with 
>> GFS? How do people provide for RAID1 type redundancy against system 
>> boot-disk failure for each of their cluster nodes if I can't setup 
>> software raid for these nodes? Do I run a cron job to sync up the two 
>> drives within the system so in case of a drive failure, I can at least 
>> boot the system using the secondary drive?
>>
>> Thanks,
>> RR
>>
>> -----Original Message-----
>> From: linux-cluster-bounces at redhat.com 
>> [mailto:linux-cluster-bounces at redhat.com] On Behalf Of Robert Peterson
>> Sent: Thursday, June 22, 2006 4:46 AM
>> To: linux clustering
>> Subject: Re: [Linux-cluster] partitioning of filesystems in cluster 
>> nodes
>>
>> Hi RR,
>>
>> For your the local root partitions on the individual nodes, it's 
>> probably best to use ext3.
>> On the SAN, use GFS and Red Hat Cluster Suite.  Then perhaps you can 
>> create a symlink from your local node's mount point to the SAN, e.g. 
>> from /mnt/gfs_san/var/spool to its local /var/spool.
>>
>> Regards,
>>
>> Bob Peterson
>> Red Hat Cluster Suite
>>
>>
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>>
> 
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