Random Short Take #84

Welcome to Random Short Take #84. There’s a bit going on, so let’s get random.

Random Short Take #83

Welcome to Random Short Take #83. Quite a few press releases in this one, so let’s get random.

Random Short Take #82

Happy New Year (to those who celebrate). Let’s get random.

Random Short Take #81

Welcome to Random Short Take #81. Last one for the year, because who really wants to read this stuff over the holiday season? Let’s get random.

Take care of yourselves and each other, and I’ll hopefully see you all on the line or in person next year.

VMware Cloud on AWS – TMCHAM – Part 8 – TRIM/UNMAP

In this edition of Things My Customers Have Asked Me (TMCHAM), I’m going to delve into some questions around TRIM/UNMAP and capacity reclamation on the VMware-managed VMware Cloud on AWS platform.

 

Why TRIM/UNMAP?

TRIM/UNMAP, in short, is the capability for operating systems to reclaim no longer used space on thin-provisioned filesystems. Why is this important? Imagine you have a thin-provisioned volume that has 100GB of capacity allocated to it. It consumes maybe 1GB when it’s first deployed. You then add 50GB of data to it. You then delete 50GB of data from the volume. You’ll still see 51GB of capacity being consumed on the filesystem. This is because older operating systems just mark the blocks as deleted, but don’t zero them out. Modern operating systems do support TRIM/UNMAP though, but the hypervisor needs to understand the commands being sent to it. You can read more on that here.

How I Do This For VMware Cloud on AWS?

You can contact your account team, and we raise a ticket to get the feature enabled. We had some minor issues recently that meant we weren’t enabling the feature, but if you’re running M16v12 or M18v5 (or above) on your SDDCs, you should be good to go. Note that this feature is enabled on a per-cluster basis, and you need to reboot the VMs in the cluster for it to take effect.

What About Migrating With HCX?

Do the VMs come across thin? Do you need to reclaim space first? If you’re using HCX to go from thick to thin, you should be fine. If you’re migrating thin to thin, it’s worth checking whether you’ve got any space reclamation in place on your source side. I’ve had customers report back that some environments have migrated across with higher than expected storage usage due to a lack of space reclamation happening on the source storage environment. You can use something like Live Optics to report on your capacity consumed vs allocated, and how much capacity can be reclaimed.

Why Isn’t This Enabled By Default?

I don’t know for sure, but I imagine it has something to do with the fact that TRIM/UNMAP has the potential to have a performance impact from a latency perspective, depending on the workloads running in the environment, and the amount of capacity being reclaimed at any given time. We recommend that you “schedule large space reclamation jobs during off-peak hours to reduce any potential impact”. Given that VMware Cloud on AWS is a fully-managed service, I imagine we want to control as many of the performance variables as possible to ensure our customers enjoy a reliable and stable platform. That said, TRIM/UNMAP is a really useful feature, and you should look at getting it enabled if you’re concerned about the potential for wasted capacity in your SDDC.

Random Short Take #80

Welcome to Random Short Take #80. Lots of press release news this week and some parochial book recommendations. Let’s get random.

Random Short Take #79

Welcome to Random Short Take #79. Where did October go? Let’s get random.

Random Short Take #78

Welcome to Random Short Take #78. We’re hurtling towards the silly season. Let’s get random.

VMware Cloud on AWS – I4i.metal – A Few Notes …

At VMware Explore 2022 in the US, VMware announced a number of new offerings for VMware Cloud on AWS, including a new bare-metal instance type: the I4i.metal. You can read the official blog post here. I thought it would be useful to provide some high-level details and cover some of the caveats that punters should be aware of.

 

By The Numbers

What do you get from a specifications perspective?
  • The CPU is 3rd generation Intel Xeon Ice Lake @ 2.4GHz / Turbo 3.5GHz
  • 64 physical cores, supporting 128 logical cores with Hyper Threading (HT)
  • 1024 GiB memory
  • 30 TiB NVMe (Raw local capacity)
  • Up to 75 Gbps networking speed
So, how does the I4i.metal compare with the i3.metal? You get roughly 2x compute, storage, and memory, with improved network speed as well.
FAQ Highlights
Can I use custom core counts? Yep, the I4i will support physical custom core counts of 8, 16, 24, 30, 36, 48, 64.
Is there stretched cluster support? Yes, you can deploy these in stretched clusters (of the same host type).
Can I do in-cluster conversions? Yes, read more about that here.
Other Considerations
Why does the sizer say 20 TiB useable for the I4i? Around 7 TiB is consumed by the cache tier at the moment, so you’ll see different numbers in the sizer. And your useable storage numbers will obviously be impacted by the usual constraints around failures to tolerate (FTT) and RAID settings.
Region Support?
The I4i.metal instances will be available in the following Regions (and Availability Zones):
  • US East (N. Virginia) – use1-az1, use1-az2, use1-az4, use1-az5, use1-az6
  • US West (Oregon) – usw2-az1, usw2-az2, usw2-az3, usw2-az4
  • US West (N. California) – usw1-az1, usw1-az3
  • US East (Ohio) – use2-az1, use2-az2, use2-az3
  • Canada (Central) – cac1-az1, cac1-az2
  • Europe (Ireland) – euw1-az1, euw1-az2, euw1-az3
  • Europe (London) – euw2-az1, euw2-az2, euw2-az3
  • Europe (Frankfurt) – euc1-az1, euc1-az2, euc1-az3
  • Europe (Paris) –  euw3-az1, euw3-az2, euw3-az3
  • Asia Pacific (Singapore) – apse1-az1, apse1-az2, apse1-az3
  • Asia Pacific (Sydney) – apse2-az1, apse2-az2, apse2-az3
  • Asia Pacific (Tokyo) – apne1-az1, apne1-az2, apne1-az4

Other Regions will have availability over the coming months.

 

Thoughts

The i3.metal isn’t going anywhere, but it’s nice to have an option that supports more cores and it a bit more storage and RAM. The I4i.metal is great for SQL workloads and VDI deployments where core count can really make a difference. Coupled with the addition of supplemental storage via VMware Cloud Flex Storage and Amazon FSx for NetApp ONTAP, there are some great options available to deal with the variety of workloads customers are looking to deploy on VMware Cloud on AWS.

On another note, if you want to hear more about all the cloudy news from VMware Explore US, I’ll be presenting at the Brisbane VMUG meeting on October 12th, and my colleague Ray will be doing something in Sydney on October 19th. If you’re in the area, come along.

Random Short Take #77

Welcome to Random Short Take #77. Spring has sprung. Let’s get random.

Finally, the blog turned 15 years old recently (about a month ago). I’ve been so busy with the day job that I forgot to appropriately mark the occasion. But I thought we should do something. So if you’d like some stickers (I have some small ones for laptops, and some big ones because I can’t measure things properly), send me your address via this contact form and I’ll send you something as a thank you for reading along.