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Re: [Xen-users] resize xen disk file

Brian Stempin wrote:
Rudi,

    Great, so existing data should still stay the same then

Yes, your data will remain untouched if you use conv=notrunc

    Ok, so you're saying that when I setup the VM's / dum_U's, and I
    get to
    the partitioning part, that I should use LVM? Even thoug h LVM is
    already being used on dom0 / the main server's hard drives? That
    sounds
    odd to me, but I'll give it a shot on my next VM deployment


That's not quite what I meant. Some people prefer to install their VMs directly to disk. Instead of having a disk stanza that contains "file:/media/storage/domainxx/disk0.img", you could use "phy:/dev/sda1". In cases where you want to use direct access, it's generally a common practice to use LVM on dom0 to make managing these physical partitions easier. The domU doesn't ever need to know that it's disk is really a LV, and thus does not need any LVM utilities installed.
Ok, I see where you're coming from. LVM is a new thing to me too, so I have opted to use img files instead which I understand more than I understand VM at this stage. So, if you were to build a server that will mainly host VM's, say 20 VM's, would you start off with LVM immediately, and then greate a new logical volume for each VM / VPS? I presume if this is the route you take, then you probably also only create them when needed, right? So, if you only have 3 clients with VM's at the moment, you only create the three needed lv's on LVM. From my understanding, you can now resize them as needed? Can one then se LVM's snapshot feature to backup these VM's / VP's while they're running?


On Thu, Mar 6, 2008 at 11:25 PM, Rudi Ahlers <Rudi@xxxxxxxxxxx <mailto:Rudi@xxxxxxxxxxx>> wrote:

    Brian Stempin wrote:
    > Rudi,
    >
    > conv=notrunc prevents dd from truncating the file.  Normally, dd
    would
    > just overwrite the file.  When using conv=notrunc, dd will leave the
    > existing data alone and stop taking on 0s when the desired file size
    > is reached.
    >
    Great, so existing data should still stay the same then?
    > Setting up LVM inside of a VM is the most useful in cases where you
    > give the VM direct disk access.  Since you have a file (or a
    series of
    > files), most of the advantages that LVM affords you are redundant.
    Ok, so you're saying that when I setup the VM's / dum_U's, and I
    get to
    the partitioning part, that I should use LVM? Even thoug h LVM is
    already being used on dom0 / the main server's hard drives? That
    sounds
    odd to me, but I'll give it a shot on my next VM deployment
    >
    > Since you're using LVM, you'll have to expand your LVM partitions
    > before you can expand the underlying EXT2 file system.  As indicated
    > earlier in this email chain, you can expand your LVM group via
    > pvresize and lvextend.
    My main system still has plenty space on the HDD's, and I use image
    files for the VM's, not seperate LV's / PV's - The only reason I
    use LVM
    is to make it easier to upgrade the HDD's
    > _______________________________________________
    > Xen-users mailing list
    > Xen-users@xxxxxxxxxxxxxxxxxxx <mailto:Xen-users@xxxxxxxxxxxxxxxxxxx>
    > http://lists.xensource.com/xen-users

    I'm learning a lot today :)

    --

    Kind Regards
    Rudi Ahlers
    CEO, SoftDux

    Web:   http://www.SoftDux.com
    Check out my technical blog, http://blog.softdux.com for Linux or
    other technical stuff, or visit http://www.WebHostingTalk.co.za
    for Web Hosting stugg




--

Kind Regards
Rudi Ahlers
CEO, SoftDux

Web:   http://www.SoftDux.com
Check out my technical blog, http://blog.softdux.com for Linux or other 
technical stuff, or visit http://www.WebHostingTalk.co.za for Web Hosting stugg


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