Are you using multiplexing (MPX)? If so what value is it set to?
Multiplexing allows you to have multiple clients backup to a single tape
device, thus driving the device at close to rated speeds, but it is
interleaving data on the tape. I.e. if you have MPX set to 10, 10 clients
would deliver data to the device and essentially Client1 would have a piece
of data every 10 "blocks". Therefore when doing a restore it would have to
read Client1 data, skip 9 "blocks", read more Client1 data, skip 9 "blocks",
and so forth. This *could* be the reason, if you are using a high MPX
number - recommendation for DLT 8000 drives is 2 to 3 MPX.
Other factors that affect restore time are, how quickly the client can write
data to disk, speed of the network pipe, or even some erroneous bug
somewhere. In general you should be able to restore 12-18GB per hour.
Steve
-----Original Message-----
From: Sen [mailto:discussion.groups AT gmx DOT net]
Sent: Thursday, April 17, 2003 7:03 PM
To: Christopher Baughman
Cc: netbackup-l; nbu-lserv; veritas-bu AT mailman.eng.auburn DOT edu
Subject: Re: [BackupScripts-L] restoration time
i am using a DLT 40/80, it took me 5+hrs to restore only 3.3GB of
data!
any idea?
----- Original Message -----
From: "Christopher Baughman" <baughmac AT Overture DOT com>
To: "Sen" <discussion.groups AT gmx DOT net>
Sent: Friday, April 18, 2003 12:08 AM
Subject: RE: [BackupScripts-L] restoration time
It shouldn't take too long, but that can best be answered based almost
entirely on your configuration. A good starting place, though, is to take
how long it takes to back up that data, and multiply that by 1.5, or even
double it. That is a very loose way to look at it that gives a fairly close
time range. It is rare that I get a restore time that equals the backup
time.
-----Original Message-----
From: Sen [mailto:discussion.groups AT gmx DOT net]
Sent: Thursday, April 17, 2003 8:33 AM
To: netbackup-l; nbu-lserv; veritas-bu AT mailman.eng.auburn DOT edu
Subject: [BackupScripts-L] restoration time
hi all,
can i have some feedback on how long it takes for you to restore 3 GB of
data using netbackup datacenter 3.4 ? thanks
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