Download:
Boot images of XPEnoboot DSM 5.2 from http://xpenology.me/downloads/
Official DSM 5.2 file from https://www.synology.com/en-global/support/download/DS3615xs
Installation:
1. upload XPEnoboot_DS3615xs_5.2-5565.1-9d792e9.vmdk and XPEnoboot_DS3615xs_5.2-5565.1-9d792e9-flat.vmdk to datastore via vSphere client
2. Edit the old boot image hard disk to IDE (0:1)
3. Then add a new Hard disk from the image uploaded above, make it as “Nonpersistent”
4. start virtual machine, select “Install/Upgrade” from boot screen, like step 1 in http://www.xpenology.nl/how-to-install-dsm-5-2/
5. click install
6. select migration
7. upload the official pat file
8. after reboot, login, open Control panel, check update. There is an DSM 5.2-5565 Update 1 file, download and upgrade.
9. (optional) after verifying everything okay, remove the old boot image harddisk [IDE(0:1)].
Appendix
DSM 5.2 support docker! If I knew it earlier, I may not install ESXi and DSM as vm…