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FreeNAS as vSphere datastore

philippn

Neophyte
Joined
Sep 26, 2018
Messages
6
Hi,

I am currently searching for manuals / documentation on how to use a freenas server as datastore for vmware.

iscsi works great - but would nfs be better? Are there settings I should use?

And how can I use the vmware snaphots?

Is there any up to date tutorial/blogpost/manual/documentation out there describing the gold standard?

Thank you,
Philipp
 

Photonit

Neophyte
Joined
May 10, 2019
Messages
5
I just finished setting up my ESXi server to use my FreeNAS for storage.

I can’t really justify a 10GBe switch, so I just installed a couple of second hand SFP+ NICs and am running peer to peer on a unique subnet.
Below is the results of my speed tests booting up a Windows10 VM including the auto login.

You can see the caching of the NAS really making a difference on the second startup.
So with these results id go for iSCSI via 10GBe.

Times.JPG
 

HoneyBadger

Mushroom! Mushroom!
Joined
Feb 6, 2014
Messages
2,501
For pure documentation, see the FreeNAS documentation on configuring iSCSI targets:
https://www.ixsystems.com/documentation/freenas/11.2-U5/sharing.html#block-iscsi

And the VMware articles on configuring iSCSI adaptors and storage:
https://docs.vmware.com/en/VMware-v...UID-C476065E-C02F-47FA-A5F7-3B3F2FD40EA8.html

For guides, there are a variety of blogposts and iXSystems forums posts available if you search for "FreeNAS vmware (yourversion) datastore (iSCSI/NFS)" - however, the vast majority of the iSCSI tutorials do not include a caution in regards to data safety. iSCSI from VMware is async by default, so any ZVOLs presented as LUNs need to have sync=always set on them.

Sync writes on spinning disks generally do not provide enough performance for VMware use, so you need to investigate the FreeNAS guide further regarding the SLOG or Separate LOG device to accelerate those:
https://www.ixsystems.com/documentation/freenas/11.2-U5/zfsprimer.html#zfs-primer

Note that the sync writes/SLOG applies to both iSCSI and NFS use - it's just not the default setting for iSCSI, so people think "wow, iSCSI is so much faster!" when they don't realize they're putting data at risk.
 

philippn

Neophyte
Joined
Sep 26, 2018
Messages
6
Thank you - that is exactly the type of information I meant.

And I am still wondering why there seems to be no whitepaper from ixsystems on their homepage....
 

philippn

Neophyte
Joined
Sep 26, 2018
Messages
6
Today I got many
Code:
ctl_datamove: tag 0x[...] on (x:x:x) aborted

in my daily security log.

I found information stating out that using RAIDZ2 for my ZFS is too slow to use it as VMWARE datastore and that one should use mirror configuration instead. Is that right? Or would using an SSD as SLOG be enough?

Meh. I am really missing such a whitepaper or best practice-paper.....;-)
 
Joined
Apr 8, 2012
Messages
123
I personally use 2 RAID 1 VDEVs in a datastore with a 60GB SLOG works well enough for my purposes (Homelab). I had used a RAIDZ1 Pool years ago it was pretty miserable at the time. I would avoid RAIDZ2 completely in VMware datastore usage but that's just my opinion though a SLOG might make it tolerable for your use case. I also have a bunch of RDM ISCSI LUNS for some SQL cluster testing I do, though I have had issues with RAM in my current Freenas (24GB) so I am about to put in a new Freenas with 64GB to hopefully solve a few issues with doing too much on my current whitebox build. (In addition to ISCSI, I have one VM and like 8 jails including PLEX) its worked well for the last 2 years but some used E5 V2 options finally made it cheap enough for me to bite.
 
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