Behind the Scenes: Episode 219 – FlexVol to FlexGroup Conversion

Welcome to the Episode 219, part of the continuing series called “Behind the Scenes of the NetApp Tech ONTAP Podcast.”

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This week on the podcast, we invite the NetApp FlexGroup Technical Director, Dan Tennant, and FlexGroup developer Jessica Peters, to talk to us about the ins and outs of converting a FlexVol to a FlexGroup in-place, with no copy and no outage!

I also cover the process in detail in this blog post:

FlexGroup Conversion: Moving from FlexVols to FlexGroups the Easy Way

Expect official documentation on it in the coming weeks.

For more information or questions about FlexGroup volumes, email us at flexgroups-info@netapp.com!

Podcast Transcriptions

We also are piloting a new transcription service, so if you want a written copy of the episode, check it out here (just set expectations accordingly):

Episode 219: FlexVol to FlexGroup Conversion Transcription

Just use the search field to look for words you want to read more about. (For example, search for “storage”)

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Be sure to give us feedback on the transcription in the comments here or via podcast@netapp.com! If you have requests for other previous episode transcriptions, let me know!

Finding the Podcast

You can find this week’s episode here:

Also, if you don’t like using iTunes or SoundCloud, we just added the podcast to Stitcher.

http://www.stitcher.com/podcast/tech-ontap-podcast?refid=stpr

I also recently got asked how to leverage RSS for the podcast. You can do that here:

http://feeds.soundcloud.com/users/soundcloud:users:164421460/sounds.rss

Our YouTube channel (episodes uploaded sporadically) is here:

Using XCP to delete files en masse: A race against rm

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XCP has traditionally been thought of as a way to rapidly migrate large amounts of data, or to scan data and generate reports. And those ideas still hold up today….

But what if i told you that you could use XCP to delete millions of files 5-6x faster than running rm on an NFS client?

Wait… why would I delete millions of files?

Normally, you wouldn’t. But in some workflows, such scratch space, this is what happens. A bunch of small files get generated and then deleted once the work is done.

I ran a simple test in my lab where I had a flexgroup volume with ~37 million files in it.

::*> vol show -vserver DEMO -volume flexgroup_16 -fields files-used
vserver volume files-used
------- ------------ ----------
DEMO flexgroup_16 37356098

I took a snapshot of that data so I could restore it later for XCP to delete and then ran rm -rf on it from a client. It took 20 hours:

# time rm -rf /flexgroup/*

real 1213m4.652s
user 1m39.703s
sys 41m16.978s

Then I restored the snapshot and deleted the same ~37 million files using XCP. That took roughly 3.5 hours:

# time xcp diag -rmrf 10.193.67.219:/flexgroup_16
real 218m17.765s
user 149m16.132s
sys 40m47.427s

So, if you have a workflow that requires you to delete large amounts of data that normally takes you FOREVER, try XCP next time…

These are VMs with limited RAM and 1GB network connections, so I’d imagine with bigger, beefier servers, those times could come down a bit more. But in an apples to apples test, XCP wins again!

Behind the Scenes: Episode 189 – ONTAP 9.6 Overview

Welcome to the Episode 189, part of the continuing series called “Behind the Scenes of the NetApp Tech ONTAP Podcast.”

This week on the podcast, we give you the lowdown on the latest ONTAP 9.6 release with ONTAP Systems Group Vice President Octavian Tanase (@octav), Senior Director of Product Management Jeff Baxter (@baxontap), and Technical Product Marketing Manager Skip Shapiro (skip.shapiro@netapp.com)! 

Join us as we talk about how ONTAP 9.6 brings more simplicity, productivity, customer use cases, data protection and security to your datacenter. 

Finding the Podcast

You can find this week’s episode here:

Also, if you don’t like using iTunes or SoundCloud, we just added the podcast to Stitcher.

http://www.stitcher.com/podcast/tech-ontap-podcast?refid=stpr

I also recently got asked how to leverage RSS for the podcast. You can do that here:

http://feeds.soundcloud.com/users/soundcloud:users:164421460/sounds.rss

Our YouTube channel (episodes uploaded sporadically) is here:

Sneak Peek! Elastic Sizing for FlexGroup Volumes in ONTAP 9.6

ONTAP 9.6 is coming soon and I recently posted a sneak peek for REST API support. But REST APIs aren’t the only new feature coming with the release. FlexGroup volumes are getting some new enhancements as well.

These include:

  • Ability to rename a FlexGroup volume
  • Ability to shrink a FlexGroup volume
  • Support for MetroCluster with FlexGroup volumes
  • SMB CA share support

One of the bigger features (albeit more under the radar) is a way for ONTAP to help FlexGroup volumes avoid failed writes to volumes due to being out of space – elastic sizing!

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Prior to ONTAP 9.6, storage administrators had to be a bit more cognizant of member volume capacity, because if a member volume ran out of space in a FlexGroup volume, the file write would fail. Since files do not stripe across member volumes, a single file could grow over time to cause issues with space allocation.

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There are a few reasons a member volume in a FlexGroup might fill up.

  • A single file that exceeds the available space of a member volume is attempted to be written. For example, a 10GB file is written to a member volume with just 9GB available.
  • A file is appended/written to over time and eventually fills up a member volume. For example, if a database resides in a member volume.
  • Snapshots eat into the active file system space available.

FlexGroup volumes do a generally good job at allocating space across member volumes, but if a workload anomaly occurs, it can throw things off. (Like if your volume is mostly a bunch of 4K files but then you zip a lot of them up and create a giant single file).

Remediation of this problem is generally growing volumes or deleting data. But usually, admins won’t notice the issue until it’s too late and “out of space” errors have occurred. That’s where Elastic Sizing comes in handy.

Elastic Sizing – An Airbag for your Data

One of our FlexGroup volume developers refers to elastic sizing as an “airbag” in that it’s not designed to stop you from getting into an accident, but it does help soften the landing when it happens.

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In other words, it’s not going to prevent you from writing large files or from running out of space, but it is going to provide a way for those writes to complete.

Here’s how it works…

  1. When a file is written to ONTAP, the system has no idea how large that file will become. The client doesn’t know. The application usually doesn’t know. All that’s known is “hey, I want to write a file.”
  2. When a FlexGroup volume receives a write request, it will get placed in the best available member based on a variety of factors – such as available capacity, inode count, time since last file creation, member volume performance (new in ONTAP 9.6), etc…
  3. When a file is placed, since ONTAP doesn’t know how big a file will get, it also doesn’t know if the file is going to grow to a size that’s larger than the available space. So, the write is allowed as long as we have space to allow it.
  4. If/when the member volume runs out of space, right before ONTAP sends an error to the client that we’ve run out of space, it will query the other member volumes in the FlexGroup to see if there’s any available space to borrow. If there is, ONTAP will add 1% of the volume’s total capacity (in a range of 10MB to 10GB) to the volume that is full (while taking the same amount from another member volume in the same FlexGroup volume) and then the file write will continue.
  5. During the time ONTAP is looking for space to borrow, that file write is paused – this will appear to the client as a performance issue. But the overall goal isn’t to finish the write fast – it’s to allow the write to finish at all. In most cases, a member volume will be large enough to provide the 10GB increment (1% of 1TB is 10GB), which is often more than enough to allow a file creation to complete. In smaller member volumes, the performance impact could be greater, as the system will need to query to borrow space more often.
  6. The capacity borrowing will maintain the overall size of the FlexGroup – for example, if your FlexGroup is 40TB in size, it will remain 40TB.

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Once files are deleted/volumes are grown and space is available in that member volume again, ONTAP will re-adjust the member volumes back to their original sizes to maintain an evenness in space.

Ultimately, elastic sizing helps remove the admin overhead of managing space, as well as worrying so much about the initial sizing/deployment of a FlexGroup. You can spend less time thinking about how many member volumes you need, what size they should be, etc.

When you combine elastic sizing in ONTAP 9.6 with features like autogrow/shrink, then ONTAP can pretty much manage your capacity in most cases and help avoid emergency space issues.

Elastic sizing = new FlexGroup use cases?

Traditionally, FlexGroup volume use cases have mainly been for unstructured NAS data, high file count environments, small files, etc. and I’ve cautioned people against putting larger files into FlexGroup volumes because of the aforementioned issues with large files/files that grow potentially filling up a member volume.

But now, with elastic sizing to mitigate those issues, along with volume autogrow/shrink, the FlexGroup use cases get a bit more expanded and interesting.

Why not put a workload with large files/files that grow on a FlexGroup now? In fact, with SMB support for Continuously Available shares for Hyper-V and SQL server, there is further proof that FlexGroup volumes are becoming more viable solutions for a variety of workloads.

You can find the latest podcast for FlexGroup volumes here:

Behind the Scenes: Episode 188 – FlexGroup Volumes Update

Welcome to the Episode 188, part of the continuing series called “Behind the Scenes of the NetApp Tech ONTAP Podcast.”

This week on the podcast, we deliver a long overdue update to Episode 46 of the Tech ONTAP podcast, where we first covered FlexGroup volumes.

We bring back lead developer Richard Jernigan – as well as Technical Director Dan Tennant – to discuss what’s new, what’s changed and what’s coming down the line for FlexGroup volumes.

Finding the Podcast

You can find this week’s episode here:

Also, if you don’t like using iTunes or SoundCloud, we just added the podcast to Stitcher.

http://www.stitcher.com/podcast/tech-ontap-podcast?refid=stpr

I also recently got asked how to leverage RSS for the podcast. You can do that here:

http://feeds.soundcloud.com/users/soundcloud:users:164421460/sounds.rss

Our YouTube channel (episodes uploaded sporadically) is here:

New White Paper! Media and Entertainment Workloads using NetApp ONTAP! #NAB2019

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Every year, the National Association of Broadcasters puts on a show to deliver the latest and greatest in media and entertainment content and technology solutions.

This year, I decided to try to piggyback on the show and put out a new white paper about how NetApp ONTAP works with media and entertainment workloads. Included in this whitepaper:

  • DreamWorks Animation case study on NetApp ONTAP
  • Media/entertainment benchmark numbers on NetApp FlexGroup volumes
  • Why you’d want to use NetApp ONTAP

You can find the white paper here:

https://www.netapp.com/us/media/wp-7301.pdf

Leave your feedback in the comments!

Behind the Scenes: Episode 182 – NetApp on NetApp: FlexGroup Volumes and ActiveIQ

Welcome to the Episode 182, part of the continuing series called “Behind the Scenes of the NetApp Tech ONTAP Podcast.”

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This week on the podcast, we invite in the guys from Customer One, who operate the NetApp on NetApp program. NetApp on NetApp is a program where we leverage the latest NetApp technologies within our own organizations. Eduardo Rivera (@mredrivera) and Faisal Salaam (https://www.linkedin.com/in/faisal-salam-754a13104/) as we discuss how NetApp is using FlexGroup volumes to power Active IQ. 

Finding the Podcast

You can find this week’s episode here:

Also, if you don’t like using iTunes or SoundCloud, we just added the podcast to Stitcher.

http://www.stitcher.com/podcast/tech-ontap-podcast?refid=stpr

I also recently got asked how to leverage RSS for the podcast. You can do that here:

http://feeds.soundcloud.com/users/soundcloud:users:164421460/sounds.rss

Our YouTube channel (episodes uploaded sporadically) is here:

New ONTAP Release = Updated Technical reports!

ONTAP 9.5 is finally available, which means technical reports are in the process of being updated. For me, that means FlexGroup volumes!

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You can find the latest updates to the FlexGroup volume documentation here:

https://www.netapp.com/us/media/tr-4571.pdf

https://www.netapp.com/us/media/tr-4557.pdf

https://www.netapp.com/us/media/tr-4571-a.pdf

https://www.netapp.com/us/media/tr-4678.pdf