New to FreeNAS - How To Back Up VMWare ESXi VMs to a FreeNAS

[jgreco]

I wouldn't install Veeam on any machine! I use GhettoVCB it's FREE and it works flawless

I already mentioned ghettoVCB upstream, so I'm not sure what this message is addressing.

With the free ESXi, you are severely limited because you do not have the VMware API's to work with, so you do not have access to things like the CBT API.

GhettoVCB carries a significant I/O penalty in that it forces the hypervisor to do a complete backup of each VM, which means it is reading each VM from storage and then writing it out to the backup target. This is a LOT of I/O, and also a lot of disk space on the backup datastore, especially if you do not have deduplication (or if you use compression). The big advantage to GhettoVCB, in addition to being "free", is that it also works on the Free ESXi because it does not require the CBT API.

Most other backup products prefer or require CBT access in order to perform their magic. This results in substantially less work for the hypervisor, in most cases, and also usually substantially less disk, but you do need to be on one of the paid VMware product tiers.

because it's CLI most people are to LAZY to learn how to use it. Most people just want to point and click.

This is probably an unfair characterization. The tool has some significant drawbacks, and most environments that have significant size would find that the additional disk space required to hold multiple full backups of their VM inventory is fairly expensive, and may even cover the cost of a CBT-capable tool. Further, as ghettoVCB is not sanctioned by VMware, any support issues that arise are not supported, and most business or enterprise deployments require the ability to get technical support from both VMware and the vendor of the backup software.

 

[bigphil]

Cool. So, does FreeNAS honor the UNMAP?

If so, then my iSCSI VMFS6 datastores, which are in use by ESXi 6.5u1 should be automagically reclaiming by default... just at the lower, and perfectly acceptable (to me) rate... right?

UNMAP most certainly works with ESXi, and works well. In FreeNAS you MUST use a zvol and device based iSCSI extent for support. An important thing to note is there are two ways UNMAP commands are issued in ESXi...in-guest and VMFS. Each method has requirements for it to work properly. If attempting to use in-guest UNMAP, I highly suggest you update your ESXi hosts with the latest updates (U1+ includes the relevant patches that fix UNMAP). There was an early bug that caused the in-guest UNMAP commands to not be aligned with the UNMAP granularity so it didn't work in all cases. Even now, the most savings is realized if formatting your vmdk's withe 32k or 64k allocation unit sizes (for NTFS). Some excellent reading on the subject can be found on Cody Hosterman's blog (here, here, and here). To then confirm you have UNMAP setup correctly, you can look at the VAAI stats using esxtop: esxtop, type "u", type "f" choose "a" and "o" and then you'll see all the VAAI stats. The columns to watch are "DELETE" (when UNMAP commands are successful) and "DELETE_F" (when UNMAP commands fail).

 

[jgreco]

UNMAP most certainly works with ESXi, and works well. In FreeNAS you MUST use a zvol and device based iSCSI extent for support. An important thing to note is there are two ways UNMAP commands are issued in ESXi...in-guest and VMFS. Each method has requirements for it to work properly. If attempting to use in-guest UNMAP, I highly suggest you update your ESXi hosts with the latest updates (U1+ includes the relevant patches that fix UNMAP). There was an early bug that caused the in-guest UNMAP commands to not be aligned with the UNMAP granularity so it didn't work in all cases. Even now, the most savings is realized if formatting your vmdk's withe 32k or 64k allocation unit sizes (for NTFS). Some excellent reading on the subject can be found on Cody Hosterman's blog (here, here, and here). To then confirm you have UNMAP setup correctly, you can look at the VAAI stats using esxtop: esxtop, type "u", type "f" choose "a" and "o" and then you'll see all the VAAI stats. The columns to watch are "DELETE" (when UNMAP commands are successful) and "DELETE_F" (when UNMAP commands fail).

I award you: Today's most information-dense and extremely useful post.