Some links to post about ESXi 6 and ESXi 7 storage and storage speed issues
Posted by jpluimers on 2021/09/09
For my link archive (most via [Wayback] sata very slow after ESXi 6.7 update – Google Search):
- Thick versus thick provisioned VMDKs: [Wayback/Archive.is] Solved: ESXi 6.7 – Windows 10 Pro VM – poor disk performan… – VMware Technology Network VMTN
- PERC firmware and driver versions were too old: [Wayback] Solved: ESXi 6.0U3 disk performance extremely slow – VMware Technology Network VMTN
- Use VMotion to move things around: [Wayback] [SOLVED] ESXi 6.7 slow ssd read rate when moving VM – Spiceworks
- GUI operations might be capped, try
dd: [Wayback] datastore – How can I speed up file tranfers on local storage in vSphere 5? – Server Fault - An older Dell OpenManage Server Administrator version slowing things down: [Wayback] Performance issue with vSphere 6.7U3 on Dell servers – vInfrastructure Blog
- Disable the native driver so the Lynx driver gets selected [Wayback] ESXi 6.5 Storage Performance Issues and Fix – VIRTUALIZATION IS LIFE!
- Passing through the Lynx PCIe to FreeNAS on a SuperMicro X10 based board (and showing how to list PCI devices; I use
lspci | grep -E -i "SAS|SATA|SCSI|RAID|SSD"for this): [Wayback] Freenas on ESXI – AHCI Passthrough – Intel C220 Lynx Point Controller | TrueNAS Community - Another FreeNAS passthrough of a Lynx PCIe device showing
esxcli storage core adapter listto ist controllers together with drivers, thenlspci -n(I tend to uselspci -v | lessfor this) to find which one to set to passthrough: [Wayback] Kaperschip: AHCI controller passthrough with a Supermicro Xeon-D motherboard
- Passing through the Lynx PCIe to FreeNAS on a SuperMicro X10 based board (and showing how to list PCI devices; I use
- The stock
vmw_ahcibeing slow,whereas the Patsburg driver isn’t (this is supposed to be fixed in ESXi 6.7): [Wayback/Archive.is] Incredibly slow disk performance – ESXi 6.5 : vmware- [Wayback] Solved: Very slow speed on SSD – VMware Technology Network VMTN
ESXi 6.5 includes a new native driver (vmw_ahci) for SATA AHCI controllers, but that introduces performance problems with a lot of controllers and/or disks.
Try to disable the native driver and revert to the older sata-ahci driver by running
esxcli system moduleset--enabled=false--module=vmw_ahciin an ESXi shell. Reboot the host to make the change effective.
- [Wayback] Solved: Very slow speed on SSD – VMware Technology Network VMTN
- In specific situations, snapshots can make things very slow [Wayback] windows 10 1809 slow – VMware Technology Network VMTN.
- Not all drivers are installed when upgrade is done through the wrong command: [Wayback] NVMe SSDs are not recognized anymore after upgrading to VMware ESXi 7 – ivobeerens.nl
- Detailed steps to fix this: [Wayback] Important – NVMe SSD not found after upgrading to ESXi 7.0
- These devices do work:
- Samsung SSD 970 EVO 1TB NVMe
- Samsung SSD 950 PRO 512GB NVMe
- Some consumer NVMe devices no longer supported, workaround is to use the old driver (which might not work for future upgrades): [Wayback] Quick Tip – Crucial NVMe SSD not recognized by ESXi 6.7 & 7.0
- Some NVMe devices (even of the same brand/type) suddenly not being visible any more: [Wayback] ESXi 6.7U2 not seeing all the NVMe, only 2 of 12 -… – VMware Technology Network VMTN
Two takeaways already:
- “get a VMUG licence, they are not that expensive and you get to lab up all the latest software.”
- when testing features (in stead of hardware support), nesting is good, though unsupported:
–jeroen
The Wiert Corner - irregular stream of stuff 
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