Veritas-bu

Re: [Veritas-bu] duplicate multi-stream backup tape

2010-04-29 19:20:24
Subject: Re: [Veritas-bu] duplicate multi-stream backup tape
From: Dean <dean.deano AT gmail DOT com>
To: Feroz Basir <feroz.basir AT gmail DOT com>
Date: Fri, 30 Apr 2010 09:20:20 +1000
Ah.... LTO1. I remember those.

In that case, multistreaming the backup to 2 drives has a good chance of speeding things up.

You'll have to modify your backup policy's selection list to split up the backup into streams, using the NEW_STREAM directive. Alternatively, if the client has several large filesystems or partitions, you could just have ALL_LOCAL_DRIVES in the selection list, and make sure "enable multiple streams" is on.

Then modify your storage unit to use two drives, but leave multiplexing per drive at 1.

When you run your bpduplicate later, a single bpduplicate will only use two drives at any time, I believe (one for read, one for write).

Cheers,
Dean

On Fri, Apr 30, 2010 at 9:12 AM, Feroz Basir <feroz.basir AT gmail DOT com> wrote:
Hi,

LTO1 tape drive. 33 MB/s.

On 30 April 2010 00:03, Dean <dean.deano AT gmail DOT com> wrote:
> What type of tape drive is it and what speed are you getting at the moment?
>
>
> On Fri, Apr 30, 2010 at 8:21 AM, Feroz Basir <feroz.basir AT gmail DOT com> wrote:
>>
>> My backup is not going through the network. Tape library is attached
>> directly to server. I'm hoping to get better time here if I use 2 tape
>> drives at the same time (multi-stream). So, 2 tapes drive = 2 streams
>> I guess.
>>
>> As for multiplexing setting, by default it set to 1 which is what I have
>> now.
>>
>> On 29 April 2010 23:02, Chapman, Scott <Scott.Chapman AT icbc DOT com> wrote:
>> > If you multistream, you will have a different backup id for each
>> > individual stream, so you will be able to dup those backup images
>> > separately, thus continue to use one read drive and one write drive.
>> >
>> > Are you sure that writing your backup with 2 drives is going to decrease
>> > your backup time that much?  You need to confirm where the bottleneck is
>> > first.  If you find that you are killing the disk on the client, and if
>> > 2 streams means that you will be reading from 2 separate disks, then
>> > will your network handle that?  I guess I'm saying, just don't be to
>> > sold on getting twice the backup speed just because you're now using two
>> > drives...
>> >
>> > HTH.
>> >
>> > Scott Chapman
>> > Senior Technical Specialist
>> > Storage and Database Administration
>> > ICBC - Victoria
>> > Ph:  250.414.7650  Cell:  250.213.9295
>> >
>> > -----Original Message-----
>> > From: veritas-bu-bounces AT mailman.eng.auburn DOT edu
>> > [mailto:veritas-bu-bounces AT mailman.eng.auburn DOT edu] On Behalf Of Feroz
>> > Basir
>> > Sent: Thursday, April 29, 2010 1:53 PM
>> > To: veritas-bu AT mailman.eng.auburn DOT edu
>> > Subject: [Veritas-bu] duplicate multi-stream backup tape
>> >
>> > Hi,
>> >
>> > I have 2 tape drives. Our backup is running too long now and been
>> > using 2 media tapes (one after another). I'm using bpduplicate to
>> > duplicate our backup tapes.
>> >
>> > Thinking of running our backup in multistream job to utilise 2 tape
>> > drives at the same time and save backup time. Hoping our backup time
>> > would be downed by half. My concern is during duplicate process. Do I
>> > need 4 tape drives in order to run multistream tape that use 2 tapes?
>> > How does one run duplicate job on multistream backup tapethat use more
>> > than one tape?
>> >
>> > Thanks for your input.
>> >
>> > --
>> > ------------
>> > regards,
>> > Feroz Basir
>> > _______________________________________________
>> > Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
>> > http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
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>>
>>
>>
>> --
>> ------------
>> regards,
>> Feroz Basir
>> _______________________________________________
>> Veritas-bu maillist  -  Veritas-bu AT mailman.eng.auburn DOT edu
>> http://mailman.eng.auburn.edu/mailman/listinfo/veritas-bu
>
>



--
------------
regards,
Feroz Basir

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