Is a DLT drive slower than a DAT drive? - Hewlett Packard

This is a discussion on Is a DLT drive slower than a DAT drive? - Hewlett Packard ; Hi all, Our backups are taking longer since we changed to DLT from DAT (about 3/4 months ago). We've not had a huge increase in business (thus more data), so I wanted to rule out that a DLT is slower ...

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Thread: Is a DLT drive slower than a DAT drive?

  1. Is a DLT drive slower than a DAT drive?

    Hi all,



    Our backups are taking longer since we changed to DLT from
    DAT (about 3/4 months ago). We've not had a huge increase in business
    (thus more data), so I wanted to rule out that a DLT is slower than a
    DAT.



    Thanks, and have a great weekend!





    Raymond Shahan

    Life is not a journey to the grave with the
    intention of arriving safely in a pretty and
    well preserved body, but rather to skid in
    broadside, thoroughly used up, totally worn out,
    and loudly proclaiming:

    -- WOW!!! What a Ride!!!




    * To join/leave the list, search archives, change list settings, *
    * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *


  2. Re: Is a DLT drive slower than a DAT drive?

    Hi Ray,

    Normally DLTs are faster. Could be slower if it is on the same SCSI
    card as your disk drives.

    Frank Gribbin
    Potter Anderson & Corroon LLP


    -----Original Message-----
    From: HP-3000 Systems Discussion [mailto:HP3000-L@RAVEN.UTC.EDU] On
    Behalf Of Ray Shahan
    Sent: Friday, April 04, 2008 12:20 PM
    To: HP3000-L@RAVEN.UTC.EDU
    Subject: [HP3000-L] Is a DLT drive slower than a DAT drive?

    Hi all,



    Our backups are taking longer since we changed to DLT from
    DAT (about 3/4 months ago). We've not had a huge increase in business
    (thus more data), so I wanted to rule out that a DLT is slower than a
    DAT.



    Thanks, and have a great weekend!





    Raymond Shahan

    Life is not a journey to the grave with the
    intention of arriving safely in a pretty and
    well preserved body, but rather to skid in
    broadside, thoroughly used up, totally worn out,
    and loudly proclaiming:

    -- WOW!!! What a Ride!!!




    * To join/leave the list, search archives, change list settings, *
    * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *

    * To join/leave the list, search archives, change list settings, *
    * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *


  3. Re: Is a DLT drive slower than a DAT drive?

    Ray,

    There are several issues and I think others have touched on it. First,
    if you are using a DLT it likes to get data in a timely manner.
    Otherwise it will do the old 'shoe shine'. This means (as pointed out by
    others) that other devices on the line can affect the bandwidth on the
    channel and starve the DLT. If you are using something like RoadRunner,
    then the CPU can be a real factor in this equation (especially single
    CPU machines).

    So, you may not only want to check the statistics portion of the report,
    but monitor your machine during backup with Glance or SOS.

    Good Luck,

    Dave

    Ray Shahan wrote:
    > Hi all,
    >
    >
    >
    > Our backups are taking longer since we changed to DLT from
    > DAT (about 3/4 months ago). We've not had a huge increase in business
    > (thus more data), so I wanted to rule out that a DLT is slower than a
    > DAT.
    >
    >
    >
    > Thanks, and have a great weekend!
    >
    >
    >
    >
    >
    > Raymond Shahan
    >
    > Life is not a journey to the grave with the
    > intention of arriving safely in a pretty and
    > well preserved body, but rather to skid in
    > broadside, thoroughly used up, totally worn out,
    > and loudly proclaiming:
    >
    > -- WOW!!! What a Ride!!!
    >
    >
    >
    >
    > * To join/leave the list, search archives, change list settings, *
    > * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *
    >
    >



    * To join/leave the list, search archives, change list settings, *
    * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *


  4. Re: Is a DLT drive slower than a DAT drive?

    What about the situation where there is a lot of data (including jumbo
    datasets), running MPE online backup, and users online. What can I do to
    speed things up. I did move the DLT off the same channel as the hard
    drives.


    Thanks to all,
    Ron Horner
    -----Original Message-----
    From: HP-3000 Systems Discussion [mailto:HP3000-L@RAVEN.UTC.EDU]On
    Behalf Of Dave Gale
    Sent: Friday, April 04, 2008 12:13 PM
    To: HP3000-L@RAVEN.UTC.EDU
    Subject: Re: Is a DLT drive slower than a DAT drive?


    Ray,

    There are several issues and I think others have touched on it. First,
    if you are using a DLT it likes to get data in a timely manner.
    Otherwise it will do the old 'shoe shine'. This means (as pointed out by
    others) that other devices on the line can affect the bandwidth on the
    channel and starve the DLT. If you are using something like RoadRunner,
    then the CPU can be a real factor in this equation (especially single
    CPU machines).

    So, you may not only want to check the statistics portion of the report,
    but monitor your machine during backup with Glance or SOS.

    Good Luck,

    Dave

    Ray Shahan wrote:
    > Hi all,
    >
    >
    >
    > Our backups are taking longer since we changed to DLT from
    > DAT (about 3/4 months ago). We've not had a huge increase in business
    > (thus more data), so I wanted to rule out that a DLT is slower than a
    > DAT.
    >
    >
    >
    > Thanks, and have a great weekend!
    >
    >
    >
    >
    >
    > Raymond Shahan
    >
    > Life is not a journey to the grave with the
    > intention of arriving safely in a pretty and
    > well preserved body, but rather to skid in
    > broadside, thoroughly used up, totally worn out,
    > and loudly proclaiming:
    >
    > -- WOW!!! What a Ride!!!
    >
    >
    >
    >
    > * To join/leave the list, search archives, change list settings, *
    > * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *
    >
    >



    * To join/leave the list, search archives, change list settings, *
    * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *

    * To join/leave the list, search archives, change list settings, *
    * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *


  5. Re: Is a DLT drive slower than a DAT drive?

    Ron Horner wrote: What about the situation where there is a lot of data (including jumbo
    datasets), running MPE online backup, and users online. What can I do to
    speed things up. I did move the DLT off the same channel as the hard
    drives.

    Ron,

    The easiest thing to do is run the backup in the C-queue... :-)

    Also, try turning software compression off, and MAXTAPEBUF.

    -Craig


    * To join/leave the list, search archives, change list settings, *
    * etc., please visit http://raven.utc.edu/archives/hp3000-l.html *


  6. Re: Is a DLT drive slower than a DAT drive?

    On Apr 4, 9:09*pm, Craig Lalley wrote:
    > Ron Horner wrote: * *What about the situation where there is a lot of data (including jumbo
    >
    > datasets), running MPE online backup, and users online. What can I do to
    > speed things up. I did move the DLT off the same channel as the hard
    > drives.
    >
    > * Ron,
    >
    > * The easiest thing to do is run the backup in the C-queue... :-)
    >
    > * Also, try turning software compression off, and MAXTAPEBUF.
    >
    > * -Craig
    >
    > * To join/leave the list, search archives, change list settings, *
    > * etc., please visithttp://raven.utc.edu/archives/hp3000-l.html*


    Well I added MAXTAPEBUF and now my backup that was 12 hours is cut to
    4.

    Nice.

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