After running EqualLogic for a couple of years now, I have never experienced any real issues with the boxes. Running what seems to be a customized version of NetBSD they have proven to be fast, and reliable systems.
I was performing what is now a routine Firmware update from version 5.1.1 to 5.1.2, I have already done this on a PS6000 we have setup for Replication with no issue what so ever, and left upgrading our production Array untill I was happy that the Replication Array was working fine with the new firmware. Satisfied I decided to update our production PS6000 to FW 5.1.2. During the upgrade I recieved a Kernel Panic and subsequent Panic Recovery, looks like the controller crashed during the update this resulted in the iSCSI targets being unavailable for a couple of minutes, the controllers did not fail over and I now have a Firmware mismatch.
After the purchase of another EqualLogic PS6000 Series Array and 4 Dell PowerConnect 5524 switches to facilite onsite replicaiton, we decided we needed to look at the iSCSI backend network and how we where going to transport the replication data across site.
The PowerConnect 5000 switch's come with some new features, such as stacking with the use of HDMI ports located on the front of the switch, and Auto detection of EqualLogic Arrays with automatic configuration of ports attached to the Array. Enabling iSCSI mode will switch on jumbo frames, flow control, spanning-tree port fast, unicast storm control and enable the switch to automatically detect an Equallogic Array connected to any of its switch ports. - NOTE there is an issue with the implementation of flow-control prior to Firmware version 18.104.22.168 A02, Released on 10/25/2011 the issue as per the Firmware release notes are;
Now that our new PS6000 is initialized and ready to go, we started to look at replication and what we wanted to achieve in terms of backup/recovery and failover/failback. The idea was to replicate our Hyper-V virtual Machines to this second PS Series group and also all our users data. The Second PS Series group will be onsite but at the furthest most point away from our primary PS Series group in a seperate building. We also needed to look at our SAN Network topology and how we needed to extend this to give us the High Availability and bandwidth we required.
EqualLogic comes with SAN based replication built into the inclusive licensing model and with tools such as SANHQ and Dell's Manual Transfer Utility or MTU for short configuring replication is once again a nice and easy process.
Firsty lets take a quick look at what EqualLogic replication is and what it involves.
If you have been keeping upto date with my previous blog articles, you will know that we have recently taken delivery of a Dell EqualLogic PS6000 32TB. My intention is to use this as a replication partner for our existing PS Series Group.
With the new EqualLogic initialized and firmware upto date, I continued to set up replication, this was again as expected with EqualLogic a quick and painless task, I will blog on setting up replication in another article.
For the initial replication we co-located our new EqualLogic in the same Datacentre as our current PS group, created replication schedules and away it went all volumes replicated and continuing to replicate on an hourly schedule, no issues what so ever. All of this on our backend iSCSI network of course.
The next task was to move our replication partner to our secondary Datacentre accross the other side of our site in a seperate building, to offer onsite replication. the link to this secondary Datacentre is a 6GB MLT using Nortel/AVAYA as now is, Ethernet Routing Switch 5500 Series. We needed a way of transporting this backened iSCSI traffic over our current network infrastructure.
This morning we have just taken delivery of our third EqualLogic PS Series array. A PS6000 with 32TB of storage, this new addition to our SAN infrastructure is going to be a replication partner to our existing EqualLogic group. I am going to be blogging about this replication project as I get going with it but firstly thought I would take the opportunity go through deploying a PS Array step by step straight out of the box and creating a new group.