what happened to /dev/xvdd in my instance?

[Yiping Zhang]

Hi, All:

I am working on a script to handle data disks. So, I added a few data disks to my instance. Then I noticed that in listVolumes api output, the third data disk actually has a deviceid 4, instead of 3 as I would expect. Sure enough, in the guest OS, I see three data disks as /dev/xvdb, /dev/xvdc, and /dev/xvde. There is no device /dev/xvdd.

Why does CloudStack skip device /dev/xvdd? I have verified this behavior on both ACS versions 4.9.3.0 and 4.11.2.0.

Yiping

[Andrija Panic]

That's a funny - and true observation - I also reproduced the same - during
hotpluging disks, and also during booting instance with already attached
disks - BUT inside VM, there are vda, vdb, vdc, vdd disks (no vde, as can
be seen in VM XML)

I though it might had something to do with ISO files, but these are (as it
seems) always attached as IDE (sdc in my case/test).

I'm still assuming this is done due to some reservations

Post by Yiping Zhang
I am working on a script to handle data disks. So, I added a few data
disks to my instance. Then I noticed that in listVolumes api output, the
third data disk actually has a deviceid 4, instead of 3 as I would expect.
Sure enough, in the guest OS, I see three data disks as /dev/xvdb,
/dev/xvdc, and /dev/xvde. There is no device /dev/xvdd.
Why does CloudStack skip device /dev/xvdd? I have verified this behavior
on both ACS versions 4.9.3.0 and 4.11.2.0.
Yiping

[Andrija Panic]

in 4.8, it's VDC that is "reserved" / missing

virsh dumpxml i-2-5748-VM | grep vd
<target dev='vda' bus='virtio'/>
<target dev='vdb' bus='virtio'/>
<target dev='vdd' bus='virtio'/>
<target dev='vde' bus='virtio'/>
<target dev='vdf' bus='virtio'/>

Post by Andrija Panic
That's a funny - and true observation - I also reproduced the same -
during hotpluging disks, and also during booting instance with already
attached disks - BUT inside VM, there are vda, vdb, vdc, vdd disks (no vde,
as can be seen in VM XML)
I though it might had something to do with ISO files, but these are (as it
seems) always attached as IDE (sdc in my case/test).
I'm still assuming this is done due to some reservations

Post by Yiping Zhang
I am working on a script to handle data disks. So, I added a few data
disks to my instance. Then I noticed that in listVolumes api output, the
third data disk actually has a deviceid 4, instead of 3 as I would expect.
Sure enough, in the guest OS, I see three data disks as /dev/xvdb,
/dev/xvdc, and /dev/xvde. There is no device /dev/xvdd.
Why does CloudStack skip device /dev/xvdd? I have verified this behavior
on both ACS versions 4.9.3.0 and 4.11.2.0.
Yiping

--
Andrija Panić