Single Disk Snapshot Feature

Wed Jan 8 06:31:11 UTC 2014

----- Original Message -----
> From: "Malini Rao" <mrao at redhat.com>
> To: "Daniel Erez" <derez at redhat.com>
> Cc: arch at ovirt.org
> Sent: Wednesday, January 8, 2014 12:08:29 AM
> Subject: Re: Single Disk Snapshot Feature
> 
> 
> ----- Original Message -----
> > From: "Daniel Erez" <derez at redhat.com>
> > To: "Malini Rao" <mrao at redhat.com>
> > Cc: arch at ovirt.org
> > Sent: Monday, January 6, 2014 4:52:35 PM
> > Subject: Re: Single Disk Snapshot Feature
> > 
> > 
> > 
> > ----- Original Message -----
> > > From: "Malini Rao" <mrao at redhat.com>
> > > To: "Daniel Erez" <derez at redhat.com>
> > > Cc: arch at ovirt.org
> > > Sent: Monday, January 6, 2014 9:09:44 PM
> > > Subject: Re: Single Disk Snapshot Feature
> > > 
> > > Daniel,
> > > 
> > > I went through the feature page and I have some questions ( mainly from
> > > the
> > > user experience perspective) that may be about the feature or about
> > > snapshots itself..not sure -
> > > 
> > > 1. Will the ability to choose disks be available only when I click on
> > > 'Create
> > > Snapshot' button on the tool bar or even when I right click an existing
> > > snapshot and trigger the create snapshot flow?
> > 
> > Disks selection will be available only when creating a new snapshot.
> > Currently, editing an existing snapshot is not applicable.
> 
> MR: I didn't mean editing a snapshot.. I am thinking when I right click an
> existing snapshot and access the create snapshot, it is basing the
> configurations of the new snapshot on the selected existing snapshot...
> right? So, if the existing snapshot has multiple disks, will the new one
> also have the multiple disks and can the user in this flow tweak that
> selection?

Actually, the create button isn't affected by snapshot selection at all.
When creating a new snapshot, we always take the active VM (which is the current
state of the VM) and make a snapshot from it. There's also a clone action
which create a VM from a selected snapshot, in which, the new VM will
consists the selected snapshot disks (but currently, no tweak of selection 
is allowed in this flow).

> 
> > 
> > > 
> > > 2. I am a little concerned about the Custom preview option in terms of
> > > how
> > > intuitive that might be. Would it be more intuitive if there was a way
> > > for
> > > the user to select multiple snapshots in the list and then click preview
> > > to
> > > get all those selected snapshots as rows with disk selection possible? My
> > > concern is that even though 'Preview' and 'Custom preview' are presented
> > > together, they behave differently - preview will send them to the preview
> > > flow for that single snapshot while, the custom preview dialog is really
> > > independent of any row selection of the snapshot list. If the multiple
> > > selection option I described will not work for any reason, then I think
> > > having a separate button with a more descriptive name such as 'Hybrid
> > > Snapshot' might help.
> > 
> > You're right, I was concerned as well regarding the non-reliance of
> > the custom button and row selection. However, currently, multiple
> > selection is not relevant for any other action (i.e. multiple selection
> > will enforce graying out all the others buttons). In addition, I'm not
> > sure it would be more intuitive for the user to select more than one
> > snapshot
> > just for doing a custom preview (as for now, multiple selection is
> > prohibited
> > in this sub-tab). Do you think that separating to a different (regular)
> > action button could work better here? (btw, not sure about 'Hybrid
> > Snapshot'
> > as the dialog is actually invoking only a preview of a snapshot rather
> > than creating one. 'Hybrid Preview' sounds good? :)
> 
> MR: I think a separate button will help. Even though it is a bit long,  how
> about 'Define Custom Snapshot Preview'?

Might be a bit too long indeed :) Maybe the revisit of action buttons separators
(as we had while back) could do the trick?

> 
> > 
> > > 
> > > 3. In the custom preview dialog, what is the column with the radio button
> > > and
> > > is that somehow related with row selection? Right now, it is creating
> > > confusion for me because it seems like I pick a snapshot with this radio
> > > button in addition to the row highlighting and then that expectation
> > > falls
> > > apart since I am able to select across rows on the disks columns. Maybe
> > > what
> > > is needed here is to remove the row highlighting for starters and also
> > > pull
> > > out the display(?) column out of the list and have a single select drop
> > > down
> > > at the bottom of the dialog so that in the grid, all you are doing is
> > > disk
> > > selection. Or maybe at least move the radio button column to the right,
> > > so
> > > it doesn't confuse with selection.
> > 
> > The radio button column is for the snapshot's 'VM configuration' which
> > consists of the other attributes of a VM. E.g.
> > name/description/cpu/nics/apps/etc.
> > I.e. this dialog allows mix-n-match only for the disks, other components
> > of the snapshot aren't configurable.
> > So a single drop down won't work here as every snapshot might contain
> > a different VM configuration, from which the user can choose.
> > Regarding the row selection - you're right, I've been already told it's
> > quite confusing. I removed it from my implementation drafts but just
> > hadn't have a chance to update the video yet...
> 
> MR: Daniel, just so it is clear, the drop down will list the snapshots. See
> attachment of a mockup I tweaked from yours. Would this not work?

Oh, now I understand. But there's another limitation (I'm not sure I've
emphasized it the wiki page) - the memory is coupled to the VM configuration,
i.e. if the users select some configuration, they could only check the
memory check-box correlated that selected configuration. So wouldn't it
be confusing / less intuitive to extract the VM configurtion, as the user
must keep in mind the selected configuration from top and make the
correlation to the list in table?

> 
> 
> > 
> > > 
> > > 4. Also, I wanted to know how many disks can we expect per row on an avg?
> > > I
> > > ask to see if the matrix format is the most suitable or if we need to
> > > think
> > > of other layouts...
> > 
> > We've tried a few variations scrolling for the dialog, e.g. keeping the
> > left hand columns (Date/Name/VM configuration) static and allow
> > horizontal scrolling only for the disks. But it seems that for
> > most use-cases, we'll have many snapshots and only a few disks.
> > Hence, it'll probably better ux-wise to keep the dialog cleaner
> > and simpler for the common use-cases while supporting rare
> > scenarios with (regular) scrollbars for the entire table.
> 
> MR: I think the static columns on the left are a great idea but that should
> appear only when the scroll becomes necessary. When the number of disks are
> small, which is possibly mostly, then the dialog is simple. But even though
> it is an edge case, I think if the snapshots column did not stay static, the
> scroll would be meaningless since you don;t know what you are picking
> anymore.
> 
> 
> > 
> > Let me know what you think, thanks a lot for the feedback!
> > 
> > > 
> > > Thanks
> > > Malini
> > > 
> > > ----- Original Message -----
> > > From: "Daniel Erez" <derez at redhat.com>
> > > To: arch at ovirt.org
> > > Sent: Sunday, December 15, 2013 12:40:06 PM
> > > Subject: Single Disk Snapshot Feature
> > > 
> > > Hi,
> > > 
> > > "Single Disk Snapshot" feature is targeted to 3.4.
> > > Please review the wiki page [1] and feel free to
> > > share your thoughts.
> > > 
> > > [1] http://www.ovirt.org/Features/Single_Disk_Snapshot
> > > 
> > > Regards,
> > > Daniel
> > > _______________________________________________
> > > Arch mailing list
> > > Arch at ovirt.org
> > > http://lists.ovirt.org/mailman/listinfo/arch
> > > 
> > 
> 