RE: Thin provisioning LUNs, A-SIS, and notifications

From: De Wit Tom (Consultant) (tom.de.wit@volvo.com)
Date: Sun Jan 27 2008 - 06:34:40 EST

  • Next message: Willeke, Jochen: "RE: Deleting many large files spikes filer CPU"

    This is idd normal behaviour. When blocks are getting filled up in your
    lun, Netapp will also notice that and the used space will grow. When
    however your file system frees blocks, this is not told to Netapp, so
    those blocks will be kept in use even when there is no data in it
    anymore. Netapp simply doesn't know they are freed.
     
    In Windows you can use Snapdrive 5 with a new feature called 'Space
    reclamation". In this case Snapdrive will scan your NTFS filesystem
    regularily and will tell Netapp which blocks can be freed. In this case
    your used space will also decrease on Netapp when you free up space in
    your lun.
     
    Grtz,
    Tom

    ________________________________

    From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com]
    On Behalf Of Daniel Keisling
    Sent: vrijdag 25 januari 2008 23:15
    To: toasters@mathworks.com
    Subject: RE: Thin provisioning LUNs, A-SIS, and notifications

    After a couple of replies, I have determined that the volume never
    decreasing is indeed normal behavior. I started SIS on the volume and
    the LUN did decrease, with great results.
     
    Now if I can just configure SNMP notification for volume autosize
    events....

    ________________________________

    From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com]
    On Behalf Of Daniel Keisling
    Sent: Friday, January 25, 2008 12:07 PM
    To: toasters@mathworks.com
    Subject: Thin provisioning LUNs, A-SIS, and notifications

    Hello,
     
    I am starting to thin provision LUNs (lun set reservation disable) in
    order to start using A-SIS on some large (1TB) volumes. Before I turn
    A-SIS on, I started testing these LUNs and do see the space on the filer
    grow accordingly with writes on the host. However, the space never
    seems to go down when I delete files on the host:
     
    rtpstore2b> df /vol/iscsi
    Filesystem kbytes used avail capacity Mounted
    on
    /vol/iscsi/ 10485760 9974748 511012 95%
    /vol/iscsi/
    /vol/iscsi/.snapshot 0 0 0 ---%
    /vol/iscsi/.snapshot
     
     
    [root@vrhel5 /]# df /mnt/iscsi
    Filesystem 1K-blocks Used Available Use% Mounted on
    /dev/sde1 10321192 7804844 1992064 80% /mnt/iscsi
     
     
    I see that when I begin writing again, the filer space won't start
    increasing until there is an increase in space above what the filter
    already thinks. Is this behavior normal? When I turn SIS on, will the
    filer LUN size reduce as blocks are deduplicated so that I can then
    reduce the volume?
     
    Lastly, I will definitely need to know when my volumes autosize so I can
    focus my attention on not having the aggregate fill up. It would be
    wonderful if I could set up an SNMP trap to send to Nagios for
    notification. Before I dig into the MIBs and create the custom trap (if
    I even can), has anyone done anything similar they could share?
     
    TIA,

    Daniel
     
     
     
     

    ______________________________________________________________________
    This email transmission and any documents, files or previous email
    messages attached to it may contain information that is confidential or
    legally privileged. If you are not the intended recipient or a person
    responsible for delivering this transmission to the intended recipient,
    you are hereby notified that you must not read this transmission and
    that any disclosure, copying, printing, distribution or use of this
    transmission is strictly prohibited. If you have received this
    transmission
    in error, please immediately notify the sender by telephone or return
    email
    and delete the original transmission and its attachments without reading
    or saving in any manner.
            

    ______________________________________________________________________
    This email transmission and any documents, files or previous email
    messages attached to it may contain information that is confidential or
    legally privileged. If you are not the intended recipient or a person
    responsible for delivering this transmission to the intended recipient,
    you are hereby notified that you must not read this transmission and
    that any disclosure, copying, printing, distribution or use of this
    transmission is strictly prohibited. If you have received this
    transmission
    in error, please immediately notify the sender by telephone or return
    email
    and delete the original transmission and its attachments without reading
    or saving in any manner.
            



    This archive was generated by hypermail 2b29 : Sun Jan 27 2008 - 07:26:13 EST