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Any way to speed up VSAN resync/rebuilds?

Does anyone know of any ways to speed up the resync or rebuild process for VSAN?

I remember reading that VSAN throttled resync I/O by default so it doesn't impact the datastore as much. However if that is not an issue for me, I would like to know if there are any advanced commands or parameters that would increase the rate of resync. I have some maintenance operations that triggered 40TB of resync and I was thinking if there was a way to increase the resync rate during weekends/offhours.

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zdickinson
Expert
Expert

My understanding is that it will only throttle if it needs too.  Otherwise it will use all available resources.  If the rebuild seems slow, and your not pushing your hardware; the bottleneck is probably the vSAN software "figuring" stuff out.  Thank you, Zach.

Quote from Duncan:  On top of that, VSAN also has a “rebuild throttling / QoS” mechanism, which will throttle back replication traffic during rebuild when this can impact virtual machine performance.

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JohnNicholsonVM
Enthusiast
Enthusiast

I'm fairly certain I saw a process for changing this (Can't seem to find it at the moment).  My advise (Much like my recommendations on adjusting cache reservation) is if it actually causes a problem please call support first.  If rebuilds are causing a problem you may have other issues (like a bad NIC firmware was something I caught because of a slow rebuild). 

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