Hello and welcome to the communities!
- I'd like to install ESXi on a SanDisk USB flash drive, so that all my HDDs are available for local storage. I know that this is both possible, and supported, however are there any particular "need-to-knows" or "gotchas" that I need to watch-out for? E.g. are there any special considerations with respect to the scratch partition? Flash drive size recommendations?
> Biggest thing is not use the USB drive for logs (i.e. configure scratch space to go somewhere else). This is to prevent the drive from failing due to overuse. Here is a great article: http://blogs.vmware.com/vsphere/2011/09/booting-esxi-off-usbsd.html - I'd like to configure my disks with 4x1TB in a RAID 10 array, and 1 hot spare. I understand that a limitation of the PERC controllers is that RAID 10 arrays cannot be segmented into multiple LUNs (or virtual disks - to use the PERC nomenclature). Am I limiting myself by having just a single LUN with 2TB of storage for what would essentially be my only VMFS datastore? To create an array that presents multiple LUNs, I'ld have to go with a RAID 5 or 6 array, an that substantially reduces write performance - so I'm reluctant to do that unless there is a compelling reason to do so.
> Based on what you are trying to do RAID 10 should be fine. The only real consideration would be disk queues. With only a single datastore you will only have a single queue, but you can adjust it if needed. - If I stick with the RAID 10 + 1 hot spare from 2 (above), what is a practical use for the sixth 1TB drive? Scratch partition? VM paging? ISO storage? Create 1 LUN or multiple LUNs? Forogore the flash drive, and isntall ESXi on it? Given that there would be no redundancy/fault tolerance for this dirve, I'm not sure of a practical use for it.
> Anything you do not care about![]()
you can technically run VMs on it as long as performance is not a concern and if the drive dies you do not care about losing the VMs. Scratch would be go as would ISO storage. VM paging would not be recommended as it will perform less than your RAID 10. You could use it as a test bed for deploying VMs / scripts / automation. Another recommendation would be to create a RAID 10 with 6 drive and no hot spares or multiple RAID 1/10 given the number of drives and forego the hot spare. After all, you can lose one drive per RAID 1 configuration. In either case, RAID is not a backup solution so if you really care about your data you should be backing it up somewhere.
you can technically run VMs on it as long as performance is not a concern and if the drive dies you do not care about losing the VMs. Scratch would be go as would ISO storage. VM paging would not be recommended as it will perform less than your RAID 10. You could use it as a test bed for deploying VMs / scripts / automation. Another recommendation would be to create a RAID 10 with 6 drive and no hot spares or multiple RAID 1/10 given the number of drives and forego the hot spare. After all, you can lose one drive per RAID 1 configuration. In either case, RAID is not a backup solution so if you really care about your data you should be backing it up somewhere.
One finaly comment. You mentioned that you have the PERC6/i RAID controller. Does it have on-board memory and/or battery backup? While the PERC6/i is supported you may find performance to be poor without at least on-board memory. Good luck!