Its taking the SS because the files are locked by the ESX hosts...
The VMDK initial offsets are scanned..a handful of blocks maybe?
That's it really. Similar to the offset scan you would run by hand.
Id bet the SS creation/deletion is most of the load..as it were.
On Wed, Apr 11, 2012 at 7:26 PM, Peta Thames petathames@gmail.com wrote:
Hi all,
I've been testing the new functionality in VSC 4 around online re-alignment. I've done some tests with a test datastore and test VM under load, all fine.
However I have an estate of over 200 datastores. Has anyone run the scan manager across all their datastores at once? Was there any noticeable impact to the VMs? As far as I can tell, I can only schedule the scan to scan everything at once. I know I could manually do batches but I need to run the scans overnight.
I've found documentation around the actual online alignment function and warnings to not do too many at once, but nothing about the scan. There also seems to be no way of stopping the scan once it starts, which makes my rollback plan in my CR for this scan a bit empty looking and hard to justify.
And a long shot, just out of curiosity, if anyone has any information on what the scan actually does would be interesting too. I can see it takes a VM snapshot for each VM in the datastore, then deletes it, but that's it. I've searched NOW high and low, but documentation on VSC 4 is pretty thin on the ground.
Thanks, Peta _______________________________________________ Toasters mailing list Toasters@teaparty.net http://www.teaparty.net/mailman/listinfo/toasters