Networker

Re: [Networker] Migrating data from staging disk to LTO3 tape

2005-09-29 09:41:00
Subject: Re: [Networker] Migrating data from staging disk to LTO3 tape
From: Terrence R Haupt <Terrence.Haupt AT ABBOTT DOT COM>
To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
Date: Thu, 29 Sep 2005 08:35:18 -0500
I can answer the the more than one saveset to a drive..  the staging to 
tape works the same as a clone, it does one at a time.  There is a bonus 
to this, the restores from those tapes are lot faster.  I performed a DR 
test in August with a client who the year before took over 20 hours to 
restore (this was backed up to tape) and this past test the restores 
finished in just over 8 hours.  All I can say is I'm hooked!


Terrence R. Haupt
SR UNIX Systems Administrator
WIN, Technology Engineering
Abbott Laboratories 
Ph: 847-938-2375 Cell: 847-878-1057
Text MSG 8478781057 AT messaging.nextel DOT com 
Nextel Direct Connect 111*4737*123
terrence.haupt AT abbott DOT com




Mark Davis <davism AT UWO DOT CA>
Sent by: Legato NetWorker discussion <NETWORKER AT LISTSERV.TEMPLE DOT EDU>
09/28/2005 03:43 PM
Please respond to Legato NetWorker discussion; Please respond to Mark 
Davis

 
        To:     NETWORKER AT LISTSERV.TEMPLE DOT EDU
        cc:     (bcc: Terrence R Haupt/LAKE/CHMS/ABBOTT)
        Subject:        Re: [Networker] Migrating data from staging disk to 
LTO3 tape


Itzik,

I am presently migrating 8 file systems to 8 tape drives simultaneously 
via one Sun V880. When I said I was getting 10-20 MB/sec of throughput 
to the tape drives, I mean when they are all running at once.

So my question really is about problems people may have had with LTO3's 
at slower data rates? And I am also wondering if anyone knows of a way 
to feed 1 tape drive with more than 1 disk migration session?

Thanks for the reply.

Mark

Itzik Meirson wrote:
> Having such a limited throughput to your LTO2 drives points to very slow
> read capability of your disk system.
> I would suggest that first of all you figure out why your disk (backup)
> device is not capable of providing higher read throughputs.
> You may have to check the service time for your device and the total
> throughput read+write.
> It might very well be that if you have multiple processes (save streams)
> writing to the same device you are reading from with only one stream
> (the staging process), the writes will monopolize on the device.
> I would try to test the read throughput by staging at a time that no new
> backups are directed to that disk device.
> Itzik 
> 
> 
>>-----Original Message-----
>>From: Legato NetWorker discussion 
>>[mailto:NETWORKER AT LISTSERV.TEMPLE DOT EDU] On Behalf Of Mark Davis
>>Sent: Wednesday, September 28, 2005 19:00
>>To: NETWORKER AT LISTSERV.TEMPLE DOT EDU
>>Subject: [Networker] Migrating data from staging disk to LTO3 tape
>>
>>We are looking at upgrading the drives in our tape library to 
>>LTO3 technology. My concern is with cloning/migrating data 
>>from our staging drives to tape. With our present 
>>environment, the throughput rate to our existing LTO2 drives 
>>ranges between 10 MB/sec to 20 MB/sec. With the
>>LTO3 drives rated at 60 MB/sec, I am worried we will get into 
>>some serious "shoe shining" with the LTO3's, due to our 
>>inability to reach the streaming rate. This shoe shining, 
>>meaning forcing the tape to continually stop, reverse, and 
>>move forward again during recording, would cause significant 
>>wear and tear on the media and the drives.
>>
>>On area where I could see improvement would be to send more 
>>than one clone/migration session to a single tape device. 
>>Does anyone know if this is possible?
>>
>>Is anyone presently cloning/migrating staging disk to LTO3 
>>drives, and have there been any issues?
>>
>>Thanks very much.
>>
>>Mark Davis
>>--
>>Mark Davis
>>Legato NetWorker Support - I.T.S
>>University of Western Ontario
>>email: davism AT uwo DOT ca
>>

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