Hi all i have a situation of a virtual machine running on esx 4.0 over iscsi this machine (while the user is running his stuff) is using a lot of i/o on a very small netapp controller (2020) with only 5 data disks aggr and getting very bad latency and eventually getting a lun reset errors and the machine freeze for a few minutes i have increased the timeouts from the windows side but it doesn't seems to help this application don't need so much i/o and can be run a 5.4k disk on an old laptop but given the resources of netapp it uses them to the fullest it is important to mention that this application is running over MSSQL db and the i/o problem goes to rdm lun my question: is there a way to limit the i/o of this machine from either netapp side /vmware side / windows side / network side i'm aweare of vmware storage i/o control but this is only supported in vsphere 4.1 and an upgrade is not an options right now i'm also aware of flexshare from the netapp side but i don't think giving low priority to this volume will help in this case is there other way you can think of to limit the i/o goes from vmware virtual machine through iscsi to an rdm lun or his hosting volume?
thank you
Is the LUN aligned properly?
On Tue, Dec 6, 2011 at 3:00 AM, Alon Zeltser alonz@emet.co.il wrote:
Hi all i have a situation of a virtual machine running on esx 4.0 over iscsi this machine (while the user is running his stuff) is using a lot of i/o on a very small netapp controller (2020) with only 5 data disks aggr and getting very bad latency and eventually getting a lun reset errors and the machine freeze for a few minutes i have increased the timeouts from the windows side but it doesn't seems to help this application don't need so much i/o and can be run a 5.4k disk on an old laptop but given the resources of netapp it uses them to the fullest it is important to mention that this application is running over MSSQL db and the i/o problem goes to rdm lun my question: is there a way to limit the i/o of this machine from either netapp side /vmware side / windows side / network side i'm aweare of vmware storage i/o control but this is only supported in vsphere 4.1 and an upgrade is not an options right now i'm also aware of flexshare from the netapp side but i don't think giving low priority to this volume will help in this case is there other way you can think of to limit the i/o goes from vmware virtual machine through iscsi to an rdm lun or his hosting volume?
thank you
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i believe so since we are talking about an rdm with an ntfs file system (created with snapdrive ) there isn't usually an alignment issue like on vmfs luns
On 12/06/2011 10:17 AM, Jeff Mohler wrote:
Is the LUN aligned properly?
On Tue, Dec 6, 2011 at 3:00 AM, Alon Zeltser <alonz@emet.co.il mailto:alonz@emet.co.il> wrote:
Hi all i have a situation of a virtual machine running on esx 4.0 over iscsi this machine (while the user is running his stuff) is using a lot of i/o on a very small netapp controller (2020) with only 5 data disks aggr and getting very bad latency and eventually getting a lun reset errors and the machine freeze for a few minutes i have increased the timeouts from the windows side but it doesn't seems to help this application don't need so much i/o and can be run a 5.4k disk on an old laptop but given the resources of netapp it uses them to the fullest it is important to mention that this application is running over MSSQL db and the i/o problem goes to rdm lun my question: is there a way to limit the i/o of this machine from either netapp side /vmware side / windows side / network side i'm aweare of vmware storage i/o control but this is only supported in vsphere 4.1 and an upgrade is not an options right now i'm also aware of flexshare from the netapp side but i don't think giving low priority to this volume will help in this case is there other way you can think of to limit the i/o goes from vmware virtual machine through iscsi to an rdm lun or his hosting volume? thank you _______________________________________________ Toasters mailing list Toasters@teaparty.net <mailto:Toasters@teaparty.net> http://www.teaparty.net/mailman/listinfo/toasters--
Gustatus Similis Pullus
Do you mean that there is a performance issue with that particular VM, or with other systems on the filer that are caused by I/O on that VM?
You should be able to use flex share to set a lower priority for a "cache-hogging" and reduce its impact on the other volumes. On the command line, run "priority on." Then run "priority set volume $volumename level=Low" for the problem volume. This will give less priority to that volume in the write cache, free up the cache for other things, and (hopefully) reduce latency on those other volumes.
In your case, you'll need to have that RDM in its own volume.
________________________________ From: Alon Zeltser alonz@emet.co.il To: toasters@teaparty.net Sent: Tuesday, December 6, 2011 6:00 AM Subject: limit i/o for lun or volume
Hi all i have a situation of a virtual machine running on esx 4.0 over iscsi this machine (while the user is running his stuff) is using a lot of i/o on a very small netapp controller (2020) with only 5 data disks aggr and getting very bad latency and eventually getting a lun reset errors and the machine freeze for a few minutes i have increased the timeouts from the windows side but it doesn't seems to help this application don't need so much i/o and can be run a 5.4k disk on an old laptop but given the resources of netapp it uses them to the fullest it is important to mention that this application is running over MSSQL db and the i/o problem goes to rdm lun my question: is there a way to limit the i/o of this machine from either netapp side /vmware side / windows side / network side i'm aweare of vmware storage i/o control but this is only supported in vsphere 4.1 and an upgrade is not an options right now i'm also aware of flexshare from the netapp side but i don't think giving low priority to this volume will help in this case is there other way you can think of to limit the i/o goes from vmware virtual machine through iscsi to an rdm lun or his hosting volume?
thank you
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