To feed the drive better you need to use multiplexing.

This must be set in 2 places. First, you must set the schedule within the
policy. I use a value of 3 for full backups and 4 for incrementals
The, the storage unit must be set. Check off enable multiplexing and set the
max streams to the highest number in use by any policy. Mine are set to 8

Multiplexing speeds up backups, but can slow restores as rthe restore will
need to skip the tape segments that belong to other clients

Jim


"eric lau" wrote in message
news:46d5d7e3@ROSASTDMZ05....
>
> Just wonder how the other system administrators do when they come to the
> backup
> performance of their clients. I have Netbackup Enterprise 6.5 installed
> with
> Quantum Scalar i500 LTO 3 Tape Library. When I tried to backup my windows
> cleints I am not getting the performance that I was told, not even half.
> I have a file server with 450G data on it. The best I do on this
> particular
> client is 15MB/Sec. I was told with LTO 3 drives, we can at least getting
> 35MB/Sec. I tried different windows clients too. They are ranging from 8
> to 22MB/Sec. I ran Veritas bpbkar32 test recommended by Veritas. It is the
> clients who can't supply the data that fast for the tape drives to backup.
> But as far as I know, there is no client configuration I can do to speed
> up the clients. So, what did I miss? I ran that "bpbkar32 -nocont F:\ 1>
> nul 2> nul ". All that test came back with disappointing results. I
> disabled
> the antivirus, veritas backup tracker, and diskeeper. I could get from
> 15mb/sec
> to 22mb/sec, but seems 22mb/sec is the best I can get from these clients.
> A lot of clients only giving me 8 to 10mb/sec. I know it's the client
> issue
> but what? Any suggestions are appreciated.
>
>

Another way is to feed the drive with large lumps of data ie bundle up the
files locally then backup the bundle. lots of small files means sluggish
performance.

unfortunately one downside of mpx'ing is that although you gain on the backup
side, you lose on the restore side, but hopefully if you rarely do restores
, this wont be much of an issue (but if you use the media for DR when you
might be restoring all the files , you may end up going painfully slowly)

"Jim Miller" wrote:
>To feed the drive better you need to use multiplexing.
>
>This must be set in 2 places. First, you must set the schedule within the

>policy. I use a value of 3 for full backups and 4 for incrementals
>The, the storage unit must be set. Check off enable multiplexing and set
the
>max streams to the highest number in use by any policy. Mine are set to
8
>
>Multiplexing speeds up backups, but can slow restores as rthe restore will

>need to skip the tape segments that belong to other clients
>
>Jim
>
>
>"eric lau" wrote in message
>news:46d5d7e3@ROSASTDMZ05....
>>
>> Just wonder how the other system administrators do when they come to the

>> backup
>> performance of their clients. I have Netbackup Enterprise 6.5 installed

>> with
>> Quantum Scalar i500 LTO 3 Tape Library. When I tried to backup my windows
>> cleints I am not getting the performance that I was told, not even half.
>> I have a file server with 450G data on it. The best I do on this
>> particular
>> client is 15MB/Sec. I was told with LTO 3 drives, we can at least getting
>> 35MB/Sec. I tried different windows clients too. They are ranging from
8
>> to 22MB/Sec. I ran Veritas bpbkar32 test recommended by Veritas. It is
the
>> clients who can't supply the data that fast for the tape drives to backup.
>> But as far as I know, there is no client configuration I can do to speed
>> up the clients. So, what did I miss? I ran that "bpbkar32 -nocont F:\
1>
>> nul 2> nul ". All that test came back with disappointing results. I
>> disabled
>> the antivirus, veritas backup tracker, and diskeeper. I could get from

>> 15mb/sec
>> to 22mb/sec, but seems 22mb/sec is the best I can get from these clients.
>> A lot of clients only giving me 8 to 10mb/sec. I know it's the client

>> issue
>> but what? Any suggestions are appreciated.
>>
>>
>
>

You know the problem is at the client, so for time being you don't worry
about network or backup server ...

You've disabled antivirus and the backup tracker, two of the easiest
ways to get poor backup performance. Assuming you've allowed Diskeeper
to do its job (you might check), you've eliminated one of the biggest
sources of slowdown in file system fragmentation.

Are you compressing or encrypting at the client? If so, turn them off
for the purposes of performance testing ... either of these will cause a
significant slowdown.

With all that out of the way, you're down to either (1) very slow disk,
that is disk unable to read large files any faster, or (2) effects of
having many files and/or folders making file system traversal difficult
for NetBackup.

The former is easy to test ... just see how fast you can read a single
very large file. If this is the problem, you need to improve the file
system ... no NetBackup tuning will help. Alternatively, accept the
performance you get and use NetBackup multiplexing to allow multiple
client data streams to go to each tape. With NetBackup tuned properly,
and with sufficient resources at the backup server, you should be able
to drive your LTO-3s.

The latter (many files) is more probable, in my experience. You still
have the multiplexing function (described above) to keep your tapes
spinning. In addition, sometimes multi-streaming (multiple streams from
one client, one stream per file system) will provide significant
improvement. For this to be a benefit, your client must have multiple
file systems, and backing them up in parallel must yield a higher
throughput than doing one at a time. For purposes of testing this,
thank, then ignore people telling you that backing up with multiple
streams on the same file system will make things worse. Maybe it would
if disk head movement was most important, but in my limited experience,
file systems with very large numbers of files have performance problems
that go way beyond a little head contention (a). Finally, you might
consider using the advanced client (I forget the 6.5 license name) to
backup the disk by blocks instead of file by file. Many people report
big gains when using this method.

(a) As examples, I have a few machines that backup in 36-54 hours,
but with multi-streaming enabled, can backup in under 12 hours. This
method can help both Windows and Linux/unix machines with large numbers
of files. Because the client is doing more work, there is more chance
that production will be adversely affected ... so watch client performance.

Hope this helps! cheers, wayne

eric lau wrote:
> Just wonder how the other system administrators do when they come to the backup
> performance of their clients. I have Netbackup Enterprise 6.5 installed with
> Quantum Scalar i500 LTO 3 Tape Library. When I tried to backup my windows
> cleints I am not getting the performance that I was told, not even half.
> I have a file server with 450G data on it. The best I do on this particular
> client is 15MB/Sec. I was told with LTO 3 drives, we can at least getting
> 35MB/Sec. I tried different windows clients too. They are ranging from 8
> to 22MB/Sec. I ran Veritas bpbkar32 test recommended by Veritas. It is the
> clients who can't supply the data that fast for the tape drives to backup.
> But as far as I know, there is no client configuration I can do to speed
> up the clients. So, what did I miss? I ran that "bpbkar32 -nocont F:\ 1>
> nul 2> nul ". All that test came back with disappointing results. I disabled
> the antivirus, veritas backup tracker, and diskeeper. I could get from 15mb/sec
> to 22mb/sec, but seems 22mb/sec is the best I can get from these clients.
> A lot of clients only giving me 8 to 10mb/sec. I know it's the client issue
> but what? Any suggestions are appreciated.