I agree - disabling the qla2xxx driver (Qlogic HBA) from starting at
boot would be the simple method of handling the issue. Then I just put
all the commands to load the driver, multipath, mdadm, etc... inside
Amusingly it seems I am missing something very basic - as I can't seem
to figure out how to not load the qla2xxx driver.
Do you happen to know the syntax to make the qla2xxx driver not load at
I've been messing with /etc/modprobe.conf - and mkinird - but no
combination has resulted in the - qla2xxx being properly disabled during
boot - I did accomplish making one of my nodes unable to mount it's root
partition - but I don't consider that success. :-)
As for your 2nd idea; I have seen folks doing something similar in that
mode; when the disks are local to the node. But in my case - all nodes
- can already see all LUNs - so I dont really have any need to do an
iSCSI export - appreciate the thought though.
Kaloyan Kovachev wrote, On 3/4/2010 10:28 AM:
On Thu, 04 Mar 2010 09:26:35 -0800, Michael @ Professional Edge LLC
Thank you for the thoughts.
You are correct when I said - "Active / Passive" - I simply meant that
had no need for "Active / Active" - and floating IP on the NFS share
would be exactly what I had in mind.
The software raid - of any type, raid1,5,6 etc... is the issue. From
what I have read - mdadm - is not cluster aware... and... since all
disks are seen by all RHEL nodes. - As Leo mentioned; some method to
disable the kernel from finding detecting and attempting to assemble
the available software raids - is a major problem. This is why I was
asking if perhaps - CLVM w/mirroring would be a better method.
since it was just introduced in RHEL 5.3 - I am a bit leery.
I am not common with FC, so maybe completely wrong here, but if you do
start multipath and load your HBA drivers on boot, how the FC disks
software raid will start at all?
even if started you may still issue 'mdadm --stop /dev/mdX' in S00 as
suggested from Leo and assemble it again as a cluster service later
Sorry for being confusing - yes - the linux machines will have a
completely different filesystem share; than the windows machines. My
original thought was I would do "node#1 primary nfs share (floating
ip#1) to linux machines w/node#2 backup" - and then "node#2 primary nfs
or samba share (floating ip#2) to windows machines w/node#1 backup".
Any more thoughts you have would be appreciated... as my original plan
with MDADM w/HA-LVM - so far doesn't seem very possible.
Then there are two services each with its own raid array and ip, but
another idea ... not using it in production, but i had good results
with (small) software raid5 array from 3 nodes ... Local device on each
exported via iSCSI and software RAID5 over the imported ones which is
used from LVM. Weird, but worked and the only problem was that on every
of any node the raid is rebuilt, which i won't happen in your case as
see all the disks in sync (after the initial sync done on only one of
... you may give it a try
Kaloyan Kovachev wrote, On 3/4/2010 8:52 AM:
On Wed, 03 Mar 2010 11:16:07 -0800, Michael @ Professional Edge LLC
Hail Linux Cluster gurus,
I have researched myself into a corner and am looking for advice.
never been a "clustered storage guy", so I apologize for the
naive set of questions. ( I am savvy on most other aspects of
hardware, OS's etc... but not storage systems).
I've been handed ( 2 ) x86-64 boxes w/2 local disks each; and ( 2 )
FC-AL disk shelves w/14 disks each; and told to make a mini NAS/SAN
required, GFS optional). If I can get this working reliably then
appear to be about another ( 10 ) FC-AL shelves and a couple of Fiber
Switches laying around that will be handed to me.
NFS filesystems will be mounted by several (less than 6) linux
and a few (less than 4) windows machines [[ microsoft nfs client ]] -
all more or less doing web server type activities (so lots of reads
a shared filesystem - log files not on NFS so no issue with high IO
writes). I'm locked into NFS v3 for various reasons. Optionally the
linux machines can be clustered and GFS'd instead - but I would still
need to come up with a solution for the windows machines - so a NAS
solution is still required even if I do GFS to the linux boxes.
Active / Passive on the NFS is fine.
Why not start NFS/Samba on both machines with only the IP floating
* Each of the ( 2 ) x86-64 machines have a Qlogic dual HBA 1 fiber
direct connected to each shelf (no fiber switches yet - but will
them later if I can make this all work); I've loaded RHEL 5.4 x86-64.
* Each of the ( 2 ) RHEL 5.4 boxes - used the 2 local disks w/onboard
fake raid1 = /dev/sda - basic install so /boot and LVM for the rest -
nothing special here (didn't do mdadm basically for simplicity of
* Each of the ( 2 ) RHEL 5.4 boxes can see all the disks on both
- and since I don't have Fiber Switches yet - at the moment there is
only 1 path to each disk; however as I assume I will figure out a
to make this work - I have enabled multipath - and therefore I have
consistent names to 28 disks.
Here's my dilemma. How do I best add Redundancy to the Disks,
as many single points of failure, and preserving as much diskspace as
My initial thought was - to take "shelf1:disk1 and shelf2:disk1" and
them into a software raid1 - mdadm; then put the resulting /dev/md0
a LVM. When I need more diskspace, I just then create "shelf1:disk2
shelf2:disk2" as another software raid1 then just add the new
into the LVM and expand the FS. This handles a couple things in my
1. Each shelf is really a FC-AL so it's possible that a single disk
going nuts could flood the FC-AL and all the disks in that shelf go
until the controller can figure itself out and/or the bad disk is
2. Efficient I am retaining 50% storage capacity after redundancy -
can do the "shelf1:disk1 + shelf2:disk2" mirrors; plus all bandwidth
used is spread across the 2 HBA fibers and nothing goes over the TCP
network. Conversely DRBD doesn't excite me much - as I then have to
both raid in the shelf (probably still with MDADM) and then I add TCP
(ethernet) based RAID1 between the nodes - and when all is said and
- I only the have 25% of storage capacity still available after
3. I easy to add more diskspace - as each new mirror (software raid1)
can just be added to an existing LVM.
You may create RAID1 (between the two shelfs) over RAID6 (on the disks
the same shelf), so you will loose only 2 more disks per shelf or
storage space left, but more stable and faster. Or several RAID6
2+2 disks from each shelf - again 50% storage space, but better
with the same chance for data loss like with several RAID1 ... the
mdX you may add to LVM and use the logical volumes
From what I can find messing with Luci (Conga) though... is - I
see any resource scripts listed for - "mdadm" (on RHEL 5.4) - so
my idea even work (I have found some posts asking for a mdadm
script but I've seen no response)? I also see with RHEL 5.3 LVM has
mirrors that can be clustered now - is this the right answer? I've
a ton of reading but everything I've dug up so far; assumes that the
fiber devices are being presented by a SAN that is doing the
before the RHEL box sees the disk... or... there are a ton of
of where fiber is not in the picture and there are a bunch of locally
attached hosts presenting storage onto the TCP (ethernet) - but I've
found nearly anything on my situation...
So... here I am... :-) I really just have 2 nodes - who can both see
a bunch of disks (JBOD) and I want to present them to multiple hosts
NFS (required) or GFS (to linux boxes only).
if the Windows and Linux data are different volumes it is better to
GFS partition(s) available only via iSCSI to the linux nodes
the cluster and not to mount it/them locally for the NFS/Samba shares,
the data should be the same you may go even Active/Active with GFS
[over CLVM and/or] [over DRBD] over RAID and use NFS/Samba over GFS as
service in the cluster. It all depends on how the data will be used
All ideas - are greatly appreciated!
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