If you’re not aware, I co-host the Tech ONTAP Podcast. I also am the TME for NetApp FlexGroup volumes. Inexplicably, we weren’t actually storing our podcast files on NetApp storage – instead, we were using the local Mac SSD, which was problematic for three reasons:
- It was eventually going to fill up.
- If it failed, bye bye files.
- It was close to impossible to access unless were were local to the Mac, for a variety of reasons.
So, it finally dawned on me that I had an AFF8040 in my lab, barely being used for anything except testing and TR writing.
At first, I was going to use a FlexVol, out of habit. But then I realized that a FlexGroup volume would provide a great place to write a bunch of 1-400MB files while leveraging all of my cluster resources. The whole process, from creating the FlexGroup, googling autofs in Mac and setting up the NFS mount and Audio Hijack, took me all of maybe 30 minutes (most of that googling and setting up autofs). Not bad!
The podcast setup
When we record the podcast, we use software called Audio Hijack. This allows us to pipe in sound from applications like WebEx and web browsers, as well as from the in-studio microphones, which all get converted to MP3. This is where the FlexGroup NFS mount comes in – we’ll be pointing Audio Hijack to the FlexGroup volume, where the MP3 files will stream in real time.
Additionally, I also migrated all the existing data over to the FlexGroup for archival purposes. We do use OneDrive to do podcast sharing and such, but I wanted an extra layer of centralized data access, and the NFS mounted FlexGroup provides that. Setting it up to stream right from Audio Hijack removes an extra step for me when processing the files. But, before I could point the software at the NFS mount, I had to configure the Mac to automount the FlexGroup volume on boot.
Creating the FlexGroup volume
Normally, a FlexGroup volume is created with 8 member volumes per node for an AFF (as per best practice). However, my FlexGroup volume was going to be around 5TB. That means 16 member volumes would be around 350-400GB each. That violates the other best practices of no less than 500GB per member, to avoid too much remote allocation. While my file sizes weren’t going to be huge, I wanted to avoid issues as the volume filled, so I met in the middle – 8 member volumes total, 4 per node. To do that, you have to go to the CLI; System Manager doesn’t do customization like that yet. In particular, you need the -aggr-list and -aggr-list-multiplier options with volume create.
ontap9-tme-8040::*> vol create -vserver DEMO -volume TechONTAP -aggr-list aggr1_node1,aggr1_node2 -aggr-list-multiplier 4ontap9-tme-8040::*> vol show -vserver DEMO -volume TechONTAP* -sort-by size -fields size,node vserver volume size node ------- --------------- ----- ------------------ DEMO TechONTAP__0001 640GB ontap9-tme-8040-01 DEMO TechONTAP__0002 640GB ontap9-tme-8040-02 DEMO TechONTAP__0003 640GB ontap9-tme-8040-01 DEMO TechONTAP__0004 640GB ontap9-tme-8040-02 DEMO TechONTAP__0005 640GB ontap9-tme-8040-01 DEMO TechONTAP__0006 640GB ontap9-tme-8040-02 DEMO TechONTAP__0007 640GB ontap9-tme-8040-01 DEMO TechONTAP__0008 640GB ontap9-tme-8040-02 DEMO TechONTAP 5TB -
Automounting NFS on boot with a Mac
When you mount NFS with a Mac, it doesn’t retain it after you reboot. To get the mount to come back up, you have to configure the autofs service on the Mac. This is different from Linux, where you can simply edit the fstab file. The process is covered very well in this blog post (just be sure to read all the way down to avoid the issue he mentions at the end):
https://coderwall.com/p/fuoa-g/automounting-nfs-share-in-os-x-into-volumes
Here’s my configuration…. I disabled “nobrowse” to prevent issues in case Audio Hijack needed to be able to browse.
autofs.conf
auto_master file
auto_nfs
After that was set up, I copied over the existing 50-ish GBs of data into the FlexGroup and cleaned up some space on the Mac.
ontap9-tme-8040::*> vol show -vserver DEMO -volume TechONTAP* -sort-by size -fields size,used vserver volume size used ------- --------------- ----- ------- DEMO TechONTAP__0001 640GB 5.69GB DEMO TechONTAP__0002 640GB 8.24GB DEMO TechONTAP__0003 640GB 5.56GB DEMO TechONTAP__0004 640GB 6.48GB DEMO TechONTAP__0005 640GB 6.42GB DEMO TechONTAP__0006 640GB 8.39GB DEMO TechONTAP__0007 640GB 6.25GB DEMO TechONTAP__0008 640GB 6.25GB DEMO TechONTAP 5TB 53.29GB 9 entries were displayed.
Then, I configured Audio Hijack to pump the recordings to the FlexGroup volume.
Then, we recorded a couple episodes, without an issue!
As you can see from this output, the FlexGroup volume is relatively evenly allocated:
ontap9-tme-8040::*> node run * flexgroup show TechONTAP 2 entries were acted on. Node: ontap9-tme-8040-01 FlexGroup 0x80F03817 * next snapshot cleanup due in 2886 msec * next refresh message due in 886 msec (last to member 0x80F0381F) * spinnp version negotiated as 4.6, capability 0x3 * Ref count is 8 Idx Member L Used Avail Urgc Targ Probabilities D-Ingest Alloc F-Ingest Alloc --- -------- - --------------- ---------- ---- ---- --------------------- --------- ----- --------- ----- 1 2044 L 1485146 0% 159376256 0% 12% [100% 100% 79% 79%] 0+ 0 0 0+ 0 0 2 2045 R 2153941 1% 159376256 0% 12% [100% 100% 98% 98%] 0+ 0 0 0+ 0 0 3 2046 L 1415120 0% 159339950 0% 12% [100% 100% 76% 76%] 0+ 0 0 0+ 0 0 4 2047 R 1690392 1% 159376256 0% 12% [100% 100% 98% 98%] 0+ 0 0 0+ 0 0 5 2048 L 1675583 1% 159376256 0% 12% [100% 100% 98% 98%] 0+ 0 0 0+ 0 0 6 2049 R 2191360 1% 159376256 0% 12% [100% 100% 98% 98%] 0+ 0 0 0+ 0 0 7 2050 L 1630946 1% 159376256 0% 12% [100% 100% 87% 87%] 0+ 0 0 0+ 0 0 8 2051 R 1631429 1% 159376256 0% 12% [100% 100% 87% 87%] 0+ 0 0 0+ 0 0 Node: ontap9-tme-8040-02 FlexGroup 0x80F03817 * next snapshot cleanup due in 3144 msec * next refresh message due in 144 msec (last to member 0x80F03818) * spinnp version negotiated as 4.6, capability 0x3 * Ref count is 8 Idx Member L Used Avail Urgc Targ Probabilities D-Ingest Alloc F-Ingest Alloc --- -------- - --------------- ---------- ---- ---- --------------------- --------- ----- --------- ----- 1 2044 R 1485146 0% 159376256 0% 12% [100% 100% 79% 79%] 0+ 0 0 0+ 0 0 2 2045 L 2153941 1% 159376256 0% 12% [100% 100% 98% 98%] 0+ 0 0 0+ 0 0 3 2046 R 1415120 0% 159339950 0% 12% [100% 100% 76% 76%] 0+ 0 0 0+ 0 0 4 2047 L 1690392 1% 159376256 0% 12% [100% 100% 98% 98%] 0+ 0 0 0+ 0 0 5 2048 R 1675583 1% 159376256 0% 12% [100% 100% 98% 98%] 0+ 0 0 0+ 0 0 6 2049 L 2191360 1% 159376256 0% 12% [100% 100% 98% 98%] 0+ 0 0 0+ 0 0 7 2050 R 1630946 1% 159376256 0% 12% [100% 100% 87% 87%] 0+ 0 0 0+ 0 0 8 2051 L 1631429 1% 159376256 0% 12% [100% 100% 87% 87%] 0+ 0 0 0+ 0 0
I plan on using this setup when I start writing the new FlexGroup data protection best practice guide, so stay tuned for that…
So, now, the Tech ONTAP podcast is happily drinking the NetApp FlexGroup champagne!
If you’re going to NetApp Insight, check out session 16594-2 on FlexGroup volumes.
For more information on NetApp FlexGroup volumes, see:
- https://newsroom.netapp.com/blogs/netapp-flexgroup-volumes-an-evolution-of-nas/
- https://newsroom.netapp.com/blogs/seven-myths-about-netapp-ontap-flexgroup-volumes/
- TR-4557: FlexGroup Volume Technical Overview
- TR-4571: FlexGroup Volume Best Practice Guide
- TR-4617: EDA Best Practice Guide
