what is xvda in .cfg files of DomU

tkmsr · 05-17-2010, 11:35 AM

I have seen following line in my LVM based DomU's

Code:

disk        = [
                  'phy:/dev/virtualization/domu1-swap,xvda1,w',
                  'phy:/dev/virtualization/domu1-disk,xvda2,w',
              ]

I want to know what is the meaning of xvda in above.
I googled but came across only one useful link
I could not understand much.

rayfordj · 05-17-2010, 03:52 PM

xvda is the first Xen Virtual Disk presented to Dom-U.

While you may name this whatever you'd like (as far as i know) it is typically one of hda, sda, xvda; if I recall, there are some performance gains by using xvda in regards to the Dom-U knowing it is para-virtualized and acting accordingly. I've not done any real testing or in-depth research on this point and may be completely off.

the stanza you present, for example, says that phy: (physical block-device... not Dom-0 file) /dev/virtualization/domu1-swap (I suspect an LV in a VG named virtualization) will be known to Dom-U as block device xvda1 (the 1st partition on xvda) with w permission (capable of read/write).

tkmsr · 05-17-2010, 11:09 PM

Yes thanks you are quite right.My problem is if I have to create a new LV for Volume group Virtualization then will it be named similarly.