This post is more than 5 years old
127 Posts
0
1149
Raid reconfig
Hi All
I have a project to re-allocate 8 LUNS on a CX3-40 from an AIX box to a Solaris box. The LUNs are Raid 1+0 on a different Raid Group.
The LUNs are 0,1,4,5,6,8,9,10
Luns 0,1 on RG0, Luns 4,5,6 on RG1 and Luns 8,9,10 on RG2.
I want to convert them to Raid 5 and want to retain the same LUN number as it will be in a cluster.
How do I go about doing this?
Both AIX and Solaris are on clusters.
AIX boxes will be decomm. The Solaris is running Solaris 8 and on SUN Cluster.
On the Solaris box, its using Veritas Vol Mgr.
I have a project to re-allocate 8 LUNS on a CX3-40 from an AIX box to a Solaris box. The LUNs are Raid 1+0 on a different Raid Group.
The LUNs are 0,1,4,5,6,8,9,10
Luns 0,1 on RG0, Luns 4,5,6 on RG1 and Luns 8,9,10 on RG2.
I want to convert them to Raid 5 and want to retain the same LUN number as it will be in a cluster.
How do I go about doing this?
Both AIX and Solaris are on clusters.
AIX boxes will be decomm. The Solaris is running Solaris 8 and on SUN Cluster.
On the Solaris box, its using Veritas Vol Mgr.
Allen Ward
2.1K Posts
0
July 9th, 2009 08:00
On a CLARiiON, drives are put together into RAID Groups. Best practice is to have groups of the same type of drive (capacity, speed, etc.) in each RAID Group.
Once a RAID Group is created, it still does not have a RAID type. It just has possible types (e.g. 5 drives could be RAID0, 3, or 5... 6 drives could be RAID 0,3,5,6, or 10).
When the first LUN is bound (created) on a RAID Group, that sets the RAID type for the RAID Group. Only LUNs of the same type can be bound on that RAID group (unless all LUNs are removed and you start again). This means that in your case, your RAID 10 RAID Groups can only have RAID 10 LUNs bound (unless your remove all the LUNs from one of them)
When a LUN is unbound it is destroyed and no longer exists. You can create another LUN with the same number after you have destroyed one, but it isn't the "same" LUN.
With the process I described in my previous post you would be able to consolidate (possibly) all your RAID 10 LUNs onto RAID groups that would stay RAID 10, then create RAID 5 LUNs on a RAID group that was freed up by migrating all the existing LUNs off of it (remember, once all LUNs are removed the RAID Group is no longer constrained as a single RAID type).
I hope this helps, and possibly makes some of the information RRR, Sandip, and I have presented here.
zainal1
127 Posts
0
July 9th, 2009 02:00
The immediate action is to retain Raid 1/0 on these LUNS.
hkcho
12 Posts
0
July 9th, 2009 02:00
RRR
5.7K Posts
0
July 9th, 2009 03:00
zainal1
127 Posts
0
July 9th, 2009 07:00
nandas
1.5K Posts
1
July 9th, 2009 07:00
In your first post, you mentioned that you want to create these LUNs in RAID5 - but if you can't destroy the RAID Groups - there is no way the LUNs can be created as RAID 5 as one RAID Group can not have one RAD1/0 LUN and another RAID 5 LUN.
Having said that, what is the requirement here?
If you plan to simply delete the data on these LUNs and re-provision it for the Solaris hosts keeping the same Size and RAID type - you may follow this
1) Delete all data on the LUN from AIX
2) unmount the LUNs on AIX
3) Remove the LUNs from the storage group for the AIX server
4) Delete the LUNs
5) Re-create the LUNs with same LUN number and same or desired size
6) Create a Storage group for the Solaris hosts
7) Add these LUNs to the new Storage Group for the Solaris hosts
8) Complete all the processes for attaching the solaris hosts to the SAN & CLARiiON - ensure proper driver, firmware on the HBA - complete the zoning accordingly, install navi agent/cli & powerpath on the hosts, edit the system configuration files etc
9) Once the solaris hosts are configured and connected to the array properly, add them to the new Storage Group
10) Scan the new disks on the solaris hosts or reboot the server recursively.
I am not really a Solaris person - so the procedure on attaching the host may need to be verified. You may refer to the Host Connectivity Guide available on Powerlink.
BTW - if you feel, the steps 4) & 5) can be avoided by keeping the same LUNs but making it available to the solaris hosts.
Hope this helps, others may correct me if needed.
Thanks,
Sandip
nandas
1.5K Posts
0
July 9th, 2009 08:00
Do not touch LUN3 (and also the storage group where it belongs) - only unbind LUN0 & LUN1, after taking them out from AIX storage group (this will not cause any issue to LUN 3 or any other LUN on the same RAID Group) - recreate them (Bind LUN) - you can use the same LUN number i.e. LUN 0 & 1 - and connect them to the new storage group for Solaris host - earlier post has all these listed
Thanks,
Sandip
zainal1
127 Posts
0
July 9th, 2009 08:00
And how do I change it to Raid5.
zainal1
127 Posts
0
July 9th, 2009 08:00
Sorry..My explanation is not very clear.
What I am trying to say is that in one the RG's consisting of the LUNS are other LUNS tat are attached to other hosts not in the list of hosts that I want to re-create.
For eg, LUN 0,1,2,3 is in RG0. All the LUNS here are Raid 1+0. But I only want to destroy and create LUN0 and LUN1 as its attached to aix1 and aix2 hosts which are cluster.
LUN3 is attached to another hosts, called aix3 which I don't intend to re-create.
So how do I do this LUN0 and LUN1 without affecting LUN3.
AranH1
2.2K Posts
1
July 9th, 2009 08:00
Allen Ward
2.1K Posts
0
July 9th, 2009 08:00
One possible solution (if all the sizes co-operate and your performance requirements won't be negatively impacted) would be this (I'm not going to recreate the steps Sandip already gave you though):
* Destroy the LUNs that you want to recreate
* Use LUN Migration to move LUNs off one or more of the RAID groups to consolidate them and free up at least one full RAID group
* Bind your new LUNs on the freed up RAID Group(s) as RAID 5
If all the sizes and performance requirements work out you should end up with new RAID 5 LUNs for your new hosts without any impact on the other LUNs for the hosts you aren't touching.