New Array Equallogic

Hello zaitochi,

Do you have an Equallogic account?  If so then you should be able to access this link which will assist you in adding a new member to a storage pool. https://dell.to/2M9ate7

Already saw this, but need good practice.

Hello zaitochi,

Have you looked at this videos and white papers.

https://dell.to/3p3GVxl

Hello, 

 Overall the best RAID policy is RAID6.  That will allow up to two failed drives and remain online. RAID5 is two RAID5s stripped together.  Two failures of the same RAIDset will cause that member to fail.  If both PS4210's are in the same pool, any volumes in common, which is the default, will go offline until the failed member is restored. 

 What firmware is the existing array running?   It should be upgraded to 10.0.3.  The best way to add in a new model is to join it to the group but put it in its own pool.  Then enable the 2nd interface, you can upgrade the firmware on this model now.  Assuming it will be compatible with your existing array if you haven't upgraded it before adding this new member.  Once that is down you can set the RAID policy and let the array build the RAIDsets.  Once completed and both members are upgraded you can MERGE the new array into the same pool.  The MERGE will happen very quickly.  In the background the array will begin moving data to the new member.  And new writes will automatically be split to both members.   So you don't need to move the volume to the new member if you are planning to put the new array into the same pool as the existing one. 

 Re: volumes.  It depends on the plan for the volume. But for Hypervisors and SQL, Exchange more smaller volumes tend to do better than one very large volume.  

 Regards, 

Don

@dwilliam62Thanks for this, yeah we planned to upgrade both firmware on the existing SAN because it is obsolete.
So it won't be a problem to have different RAID on the EQL?

When placing more than one member into a pool the volumes will spread over the members of the given pool. If you use different RAID levels you will get different performance. In most cased this might not be a problem for your applications but you should avoid this.

Regards,
Joerg

Hello, 

 In this case you can convert from RAID50 to RAID6 without resetting the array. You go to that member, at the CLI:  Grpname>member select MEMBERNAME raid-policy raid6   The process will run in the background. You can do that now or later.

You can mix RAID50 and RAID6 together. They will have different performance profiles is the downside. But you are also gaining many more IOs by adding in the 2nd unit. 

Regards, 

Don

So if I understand well what  u said, I have choice to keep two different RAID on my pool but the best that will be to convert my first RAID before adding the second EQL and put the second in RAID 6 two.

Hello, 

 Yes you can keep them at different RAID levels. You can do the conversion now or after the merge.  i would probably do it after you have upgraded that member to 10.0.3.   

 Regards,

Don