We currently have several old guests that we are removing from the inventory and recovering their resources. I''ve ran in to a minor (probably very simple) issue. Instead of using logical volumes like the rest of our guests, these ones are using tap:aio: The main question is, is there anything special I need to do to reclaim the resources from these disks, or is it as simple as just deleting these images? My second(ary) question is, what is tap:aio:? I''ve been searching but have been unable to find anything definitive on what they are. Is it just a disk image used by Xen, or is there something special about it? How is a tap:aio: disk created, etc? Thanks _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Fajar A. Nugraha
2010-Apr-06 09:55 UTC
Re: [Xen-users] Recovering resources from old guests
On Tue, Apr 6, 2010 at 4:27 AM, Caleb Call <caleb@macjunk.net> wrote:> We currently have several old guests that we are removing from the inventory > and recovering their resources. I''ve ran in to a minor (probably very > simple) issue. Instead of using logical volumes like the rest of our > guests, these ones are using tap:aio: The main question is, is there > anything special I need to do to reclaim the resources from these disks, or > is it as simple as just deleting these images?That''s pretty much it. Make sure the guest is not running, then you can delete the file images.> My second(ary) question is, > what is tap:aio:? I''ve been searching but have been unable to find > anything definitive on what they are. Is it just a disk image used by Xen, > or is there something special about it? How is a tap:aio: disk created, > etc?The image itself is basically just a raw disk image. What makes tap:aio:/ different from file:/ (or manually creating loopback devices) is that tap:aio is supposed to be more reliable and have better performance, not effected by dom0 caching effect, thus reducing possible data loss. This is different from (for example) tap:qcow, which uses its own (not raw) file format. See http://wiki.xensource.com/xenwiki/blktap for details -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Thanks. However, I tried to get rid of one of them, made sure it wasn''t running, removed the disk image and then removed the config file. I ran a vgdisplay before and after and I didn''t gain the disk space back that I should have. Any thoughts? Thanks again ##### Before I removed the disk image ##### --- Volume group --- VG Name vmvol01 System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 38 VG Access read/write VG Status resizable MAX LV 0 Cur LV 18 Open LV 7 Max PV 0 Cur PV 2 Act PV 2 VG Size 455.99 GB PE Size 4.00 MB Total PE 116734 Alloc PE / Size 56832 / 222.00 GB Free PE / Size 59902 / 233.99 GB VG UUID s96CmA-1d2x-O1Oo-rrCr-M7n6-dvRQ-AEJjcI ##### After I removed the disk image ##### --- Volume group --- VG Name vmvol01 System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 38 VG Access read/write VG Status resizable MAX LV 0 Cur LV 18 Open LV 7 Max PV 0 Cur PV 2 Act PV 2 VG Size 455.99 GB PE Size 4.00 MB Total PE 116734 Alloc PE / Size 56832 / 222.00 GB Free PE / Size 59902 / 233.99 GB VG UUID s96CmA-1d2x-O1Oo-rrCr-M7n6-dvRQ-AEJjcI On Tue, Apr 6, 2010 at 3:55 AM, Fajar A. Nugraha <fajar@fajar.net> wrote:> On Tue, Apr 6, 2010 at 4:27 AM, Caleb Call <caleb@macjunk.net> wrote: > > We currently have several old guests that we are removing from the > inventory > > and recovering their resources. I''ve ran in to a minor (probably very > > simple) issue. Instead of using logical volumes like the rest of our > > guests, these ones are using tap:aio: The main question is, is there > > anything special I need to do to reclaim the resources from these disks, > or > > is it as simple as just deleting these images? > > That''s pretty much it. Make sure the guest is not running, then you > can delete the file images. > > > My second(ary) question is, > > what is tap:aio:? I''ve been searching but have been unable to find > > anything definitive on what they are. Is it just a disk image used by > Xen, > > or is there something special about it? How is a tap:aio: disk created, > > etc? > > The image itself is basically just a raw disk image. What makes > tap:aio:/ different from file:/ (or manually creating loopback > devices) is that tap:aio is supposed to be more reliable and have > better performance, not effected by dom0 caching effect, thus reducing > possible data loss. This is different from (for example) tap:qcow, > which uses its own (not raw) file format. See > http://wiki.xensource.com/xenwiki/blktap for details > > -- > Fajar >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
Hi, maybe I''m following this thread incorrectly, but - these old tap:aio: guest VMs had file based HDD images right? In that case they were stored probably on some of the LVs. So if you deleted the img files, the free space increased on that particular LVs. But that particular LVs are still the same size as they were before (just there''s more free space on them), so they still "occupy" the same number of PE (physical extents), so number of free/unallocated PE will remain also the same. If you want more free/unallocated space in your VG, you have to shrink or remove some of the existing LVs. In case I missed the point completly - I''m sorry. :) Regards Matej -----Original Message----- From: xen-users-bounces@lists.xensource.com [mailto:xen-users-bounces@lists.xensource.com] On Behalf Of Caleb Call Sent: Tuesday, April 06, 2010 6:39 PM To: Fajar A. Nugraha Cc: Xen-users@lists.xensource.com Subject: Re: [Xen-users] Recovering resources from old guests Thanks. However, I tried to get rid of one of them, made sure it wasn''t running, removed the disk image and then removed the config file. I ran a vgdisplay before and after and I didn''t gain the disk space back that I should have. Any thoughts? Thanks again ##### Before I removed the disk image ##### --- Volume group --- VG Name vmvol01 System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 38 VG Access read/write VG Status resizable MAX LV 0 Cur LV 18 Open LV 7 Max PV 0 Cur PV 2 Act PV 2 VG Size 455.99 GB PE Size 4.00 MB Total PE 116734 Alloc PE / Size 56832 / 222.00 GB Free PE / Size 59902 / 233.99 GB VG UUID s96CmA-1d2x-O1Oo-rrCr-M7n6-dvRQ-AEJjcI ##### After I removed the disk image ##### --- Volume group --- VG Name vmvol01 System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 38 VG Access read/write VG Status resizable MAX LV 0 Cur LV 18 Open LV 7 Max PV 0 Cur PV 2 Act PV 2 VG Size 455.99 GB PE Size 4.00 MB Total PE 116734 Alloc PE / Size 56832 / 222.00 GB Free PE / Size 59902 / 233.99 GB VG UUID s96CmA-1d2x-O1Oo-rrCr-M7n6-dvRQ-AEJjcI On Tue, Apr 6, 2010 at 3:55 AM, Fajar A. Nugraha <fajar@fajar.net> wrote: On Tue, Apr 6, 2010 at 4:27 AM, Caleb Call <caleb@macjunk.net> wrote: > We currently have several old guests that we are removing from the inventory > and recovering their resources. I''ve ran in to a minor (probably very > simple) issue. Instead of using logical volumes like the rest of our > guests, these ones are using tap:aio: The main question is, is there > anything special I need to do to reclaim the resources from these disks, or > is it as simple as just deleting these images? That''s pretty much it. Make sure the guest is not running, then you can delete the file images. > My second(ary) question is, > what is tap:aio:? I''ve been searching but have been unable to find > anything definitive on what they are. Is it just a disk image used by Xen, > or is there something special about it? How is a tap:aio: disk created, > etc? The image itself is basically just a raw disk image. What makes tap:aio:/ different from file:/ (or manually creating loopback devices) is that tap:aio is supposed to be more reliable and have better performance, not effected by dom0 caching effect, thus reducing possible data loss. This is different from (for example) tap:qcow, which uses its own (not raw) file format. See http://wiki.xensource.com/xenwiki/blktap for details -- Fajar _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
OK, that sounds correct and makes sense. The Xen world is a new thing to me, I have a background with OpenVZ and VMWare...and now I''m getting to learn Xen. Thanks! On Tue, Apr 6, 2010 at 2:53 PM, Matej Zary <zary@cvtisr.sk> wrote:> Hi, > > maybe I''m following this thread incorrectly, but - these old tap:aio: guest > VMs had file based HDD images right? In that case they were stored probably > on some of the LVs. So if you deleted the img files, the free space > increased on that particular LVs. But that particular LVs are still the same > size as they were before (just there''s more free space on them), so they > still "occupy" the same number of PE (physical extents), so number of > free/unallocated PE will remain also the same. If you want more > free/unallocated space in your VG, you have to shrink or remove some of the > existing LVs. > > In case I missed the point completly - I''m sorry. :) > > Regards > > Matej > > > -----Original Message----- > From: xen-users-bounces@lists.xensource.com [mailto: > xen-users-bounces@lists.xensource.com] On Behalf Of Caleb Call > Sent: Tuesday, April 06, 2010 6:39 PM > To: Fajar A. Nugraha > Cc: Xen-users@lists.xensource.com > Subject: Re: [Xen-users] Recovering resources from old guests > > Thanks. However, I tried to get rid of one of them, made sure it wasn''t > running, removed the disk image and then removed the config file. I ran a > vgdisplay before and after and I didn''t gain the disk space back that I > should have. Any thoughts? > > Thanks again > > > ##### Before I removed the disk image ##### > --- Volume group --- > VG Name vmvol01 > System ID > Format lvm2 > Metadata Areas 2 > Metadata Sequence No 38 > VG Access read/write > VG Status resizable > MAX LV 0 > Cur LV 18 > Open LV 7 > Max PV 0 > Cur PV 2 > Act PV 2 > VG Size 455.99 GB > PE Size 4.00 MB > Total PE 116734 > Alloc PE / Size 56832 / 222.00 GB > Free PE / Size 59902 / 233.99 GB > VG UUID s96CmA-1d2x-O1Oo-rrCr-M7n6-dvRQ-AEJjcI > > ##### After I removed the disk image ##### > --- Volume group --- > VG Name vmvol01 > System ID > Format lvm2 > Metadata Areas 2 > Metadata Sequence No 38 > VG Access read/write > VG Status resizable > MAX LV 0 > Cur LV 18 > Open LV 7 > Max PV 0 > Cur PV 2 > Act PV 2 > VG Size 455.99 GB > PE Size 4.00 MB > Total PE 116734 > Alloc PE / Size 56832 / 222.00 GB > Free PE / Size 59902 / 233.99 GB > VG UUID s96CmA-1d2x-O1Oo-rrCr-M7n6-dvRQ-AEJjcI > > On Tue, Apr 6, 2010 at 3:55 AM, Fajar A. Nugraha <fajar@fajar.net> wrote: > > > On Tue, Apr 6, 2010 at 4:27 AM, Caleb Call <caleb@macjunk.net> > wrote: > > We currently have several old guests that we are removing from the > inventory > > and recovering their resources. I''ve ran in to a minor (probably > very > > simple) issue. Instead of using logical volumes like the rest of > our > > guests, these ones are using tap:aio: The main question is, is > there > > anything special I need to do to reclaim the resources from these > disks, or > > is it as simple as just deleting these images? > > > That''s pretty much it. Make sure the guest is not running, then you > can delete the file images. > > > > My second(ary) question is, > > what is tap:aio:? I''ve been searching but have been unable to > find > > anything definitive on what they are. Is it just a disk image > used by Xen, > > or is there something special about it? How is a tap:aio: disk > created, > > etc? > > > The image itself is basically just a raw disk image. What makes > tap:aio:/ different from file:/ (or manually creating loopback > devices) is that tap:aio is supposed to be more reliable and have > better performance, not effected by dom0 caching effect, thus > reducing > possible data loss. This is different from (for example) tap:qcow, > which uses its own (not raw) file format. See > http://wiki.xensource.com/xenwiki/blktap for details > > -- > Fajar > > > > > _______________________________________________ > Xen-users mailing list > Xen-users@lists.xensource.com > http://lists.xensource.com/xen-users >_______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users