It’s quite an old topic, but I recently found a great tool which allows you to re-align partitions without the need to manually move data from the misaligned disk to a new aligned disk.
First of all I must add that all the credits go to Nicholas Weaver, since he wrote the original blog and the actual tool!
We’ve all been there: you have a certain Windows virtual machine with several disks of the same size and you don’t know which Windows-disk is in fact which storage LUN.
The VMware settings for this VM might look like this:
A while ago I talked about Hot Spares and how they are picked when a rebuild is necessary. It was almost 2 years ago and you can read it here.
Since then the rebuild / equalize technology has changed! Well, not for existing systems, but the new VNX family aka VNX2 does things a bit differently.
In the old days when a drive failed, a suitable Hot spare would kick in and the unprotected LUNs (regarding the failed drive) would be rebuild onto the Hot Spare. After a while, when the rebuild was done and the failed drive was replaced by a replacement drive, the data on the Hot spare would need to be copied to that new drive. This was called equalizing.
In the VNX2 (with MCx) this last step doesn’t exist anymore. So that means the Hot spare that was used to contain the rebuilt data is not longer a Hot Spare! It has become a regular drive! And that replacement drive will now be a new Hot Spare. When configuring a new VNX2 you’d see rules about Hot Spares and you simply don’t even need to configure Hot Spares anymore. Just make sure you have some unconfigured drives and you’re good. Your VNX2 will make sure they’re used as Hot Spares from then on.
If I remember correctly the DMX4 had a similar feature back in 2008, but it now flowed to the midrange platform as well.
EMC’s Symmetrix already knew this feature for a decade or so (or even longer), but since a few years EMC’s pushing customers to make every array to email home once a week so they can keep track of its pulse. And they’re not joking about its importance either, since once an array skips a beat, a severity 1 ticket is being created to get that fixed as soon as possible. EMC truly seems to care about the arrays they have running all over the world, so they’re indeed in good shape and being monitored actively.
A little late, but better late than never. This last EMC World post has been sitting in my drafts, knowing two of my coleagues already posted theirs about the exact same thing that I wanted to talk about. And since I don’t want to play copy cat, I’m going to refer to their posts. That seems the best thing to do.
Thursday is traditionally (half) a day to say goodbye to the many old and new friends, visit some last day sessions, leave the hotel and head back to the airport, but this year I planned ahead and I decided to stay a bit longer for some quality time with the EMC Elect: My plane wouldn’t leave until Saturday afternoon!! I had to switch hotels though from the fancy and luxurious Venetian to the hotel next door “Harrah’s”. It’s a huge step down, but Harrah’s does what it’s supposed to do and that’s offering me a bed to sleep.
EMC Elect 2013, 2014, 2015, 2016 and
Dell EMC Elect 2017
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