Hey AOCTS, welcome to the site!

Great questions -- I did a little research & ran it by one of our guru's and this is what I got back:
You can do this, but it is not best practice, and the volumes will be distributed over both types of disk unless you take further steps such as setting RAID preference on each volume (assuming that the arrays are not at the same RAID type). Far better to simply migrate a couple of lower IO volumes from the SAS array to the SATA array – use SANHQ to pick the best ones to move. Either of these operations (migrate volumes, merge pools) can be done with volumes online and no downtime to the applications.

You might take a look at this page on how to plan storage pools:
http://psonlinehelp.equallogic.com/V4.2/Content/AdminNewBook/Default_Storage_Pool.htm#AdminNew_pools_4023576373_1137785

Per the documentation links below, the merge can happen with existing, attached volumes.

Documentation on merge procedure can be found here :
Command line:http://psonlinehelp.equallogic.com/V4.0/Content/GABook/pool.htm#kanchor583
Gui:http://psonlinehelp.equallogic.com/V4.2/Content/AdminNewBook/Merging_Storage_Pools.htm#AdminNew_pools_4023576373_1139185

Thanks for the detailed reply and the welcome. I am new to Equallogic, so I will have many questions I am sure. I come from a more traditional FC SAN background, and I am used to being able to have data on the high performance disks and snapshots and replication replicas on cheaper SATA.

So, as I understand, since I have both my SATA and SAS pools at the same raid level, It would probably be best to leave the two pools and just move the volumes as needed. And, because they are in two pools, I will not be able to save the snapshots or replicas for the volume on the other volume? My orginal goal was to have the data accessed on the SAS drives and the snapshots and replicas on SATA, I guess I am just out of luck...

Thanks!

I too came from the land of orange wires. :)

I went back to the previous guru for a follow-up to your comment:
Well, the differences between the snapshot placement is not related to the transport mechanism, but instead the snapshot methodology used. The array that you have used in the past used copy on write (COW), whereas EqualLogic uses an allocate on write (AOW) based process. COW is good for placing snapshots on alternate media, but you pay a large performance penalty whenever you change data since the data must be first read from the old LUN then re-written to the snapshot LUN. The overhead associated with this read/multi-write process typically limits COW based systems to about 8 snapshots active at any given time since the system suffers more and more performance penalty every time you add a snapshot. EqualLogic is able to support up to 512 snapshots per volume because we don’t use COW, which opens up a whole new vista of possibilities in terms of designing a local data protection scheme to meet your RPO requirements with outstanding RTO associated with recovery from snapshots vs. traditional backup methodologies.

Out of luck? No, not really. As you have noted, EqualLogic supports having multiple pools of storage, and customers often use disk type as the reason that they choose to create more than one pool. Replication with EqualLogic is between EqualLogic groups, not pools within a single group. EqualLogic does support making clones which, once created, can be migrated seamlessly to a second pool containing the alternate media. If you don’t want to invoke the process yourself, you could write a script to do this for you periodically. While technically somewhat different than what you had envisioned, ultimately the end result is the same – you have a point in time copy of your data that is running on SAS saved on SATA.

Thanks, makes sense. I appreciate the detailed response, It helps to understand how things are going on to help me figure out the best way to do things. I believe that we purchased things a little differently than we should have do to misunderstanding how things worked. But sounds like we can figure out the best way to use what we have to get where we need to be.

Hi , this is the firt time I am working on dell storage.

I have sas ps6000vx & sata ps6000E, I want to use sas for mailbox exchange & file and print servers with Raid 5, and planned to use sata for backup archiving with Raid 50.

I want both the members to be in single group for easy management. SAS is of 7.2 TB and sata 16 TB. I dont have any DR site and dont require replication.however I want to protect my data.

My questions are.

1. Is the above design Good?
2. Can i create single pool with sas and sata member with raid 5 and raid 50 or better to have 2 seperate pool?
3. Can I create snapshot for sas(for exchange & File) and direct it to save in sata , if it is possible then will it take 100% of the size of the volume whih is created for exchange ?

Thanks in Advance.


Regards

First, I wouldn't suggest you use RAID-5 with Exchange. RAID-5 provides the least performance and has the highest risk. RAID-50 or RAID-6 would be a better choice, for performance RAID-10 would be best.

SAS and SATA should be in different pools. See this thread for more info on that. You also get more iSCSI connections with pools, currently 512 iSCSI connections per pool for a 2048 MAX.

Re: Snapshot. Snapshot reserve stays with the pool, so no you can't create a snapshot on the SAS member and save it to the SATA member.

-don

Thanks , I did teh same way mentioned by Donald. Also Is there any configuration need to be done on swicthes , I have dell powerconenct 6248 and I am using them only for the storage connectivity. Is there any tool by DELL where I can fins what is my data transfer rate or the Trafic of e0, e1, e2 & e4, if they are equally distributed.

Also is there an simulator of dell equallogic where I can download and play around.


regards

Idrees Ahmed

I'm just learning this stuff, but SAN Head Quarters (http://delltechcenter.com/page/Dell+EqualLogic+SAN+HEADQUARTERS) looks like what you need for looking at the traffic. Pretty cool tool that was very easy to get going. Under network -> ports, you get a graph of throughput and a table of each port with send and receive stats.

Not sure on anything for a simulator....

"Thanks , I did teh same way mentioned by Donald. Also Is there any configuration need to be done on swicthes , I have dell powerconenct 6248 and I am using them only for the storage connectivity. Is there any tool by DELL where I can fins what is my data transfer rate or the Trafic of e0, e1, e2 & e4, if they are equally distributed.

Also is there an simulator of dell equallogic where I can download and play around.


regards

Idrees Ahmed"

If you contact EQL support they have a document on configuring the 62xx series switches.
Big items: Flowcontrol enabled, MTU 9216, Portfast on all the ports used for servers/arrays, don't use default VLAN if you are going to use Jumbo Frames. Lastly, make sure you have the latest switch firmware. If you have two switches, make sure they are connected with the stacking cable.

Sorry, no simulator

-don