I'd have a look on the filer and see what performance you can get without
Legato and the tape drives in the mix.  It is possible to have poor data
layout on the filer (likely due to adding a small number of disks to a
volume when it was almost full), volume fragmentation, an overworked CPU, or
simply not enough spindles underneath the dataset to feed the backup at
higher speeds.

To test read performance on the filer use dump sending the data to the null
device:
filer> dump 0uf null /vol/volname
or
filer> dump 0uf null /vol/volname/qtreename/subdirname

You'll see the various dump phases executed and can get an idea of each
phase and how long it takes.

You can also use:
filer> sysstat -xs 1
to see throughput you're getting from the spindles, and how hard you're
pushing the CPU resources of the filer.

If you have a license for snapmirror you can also use volume snapmirror to
send the data to null:
filer> snapmirror store vol0 null

The snapmirror method does a block-by-block backup and should be faster.
This sort of test will at least show you what your filer volume is capable
of and things like lots of small files, poor logical data layout, and
fragmentation won't have any effect.  After you run the command you'll need
to manually delete a snapshot that was created by the command.

Hope that helps!

Cheers,
-Chris Madden

----- Original Message -----
From: "Krishnan, Ramamurthy (Temp)" <Ramamurthy.Krishnan AT KPMG.CO DOT UK>
To: <NETWORKER AT LISTMAIL.TEMPLE DOT EDU>
Sent: Friday, March 26, 2004 15:13
Subject: Re: [Networker] Slow filer backups


NDMP does'nt support multiple streams to single drive at a given point of
time.  If you have multiple drives, you can send multiple streams (1 stream
/ device).

Rgds

- Krishnan

> -----Original Message-----
> From: Jack Lyons [mailto:jack.lyons AT MARTINAGENCY DOT COM]
> Sent: 26 March 2004 13:03
> To: NETWORKER AT LISTMAIL.TEMPLE DOT EDU
> Subject: Re: [Networker] Slow filer backups
>
>
> When you say NDMP doesn't support multiple streams.  Are you
> saying that if
> there are two drives and two volumes, that I won't be able to
> back them up
> simultaneously?
>
> BTW, We are getting 1.2 TB backed up at an average of 21MB/s
> to a single
> LTO-1 but we were planning on adding another drive when we
> moved another
> 800GB to the filer, but it seems that I might not get any
> improvement in
> speed.
>
> -----Original Message-----
> From: Krishnan, Ramamurthy (Temp)
> [mailto:Ramamurthy.Krishnan AT KPMG.CO DOT UK]
> Sent: Tuesday, March 16, 2004 3:44 AM
> To: NETWORKER AT LISTMAIL.TEMPLE DOT EDU
> Subject: Re: [Networker] Slow filer backups
>
> Parallelism would have made some difference, of course.  But
> since NDMP
> does'nt support multiple streams, we can't compare
> hand-to-hand with NDMP
> and non-NDMP backup speeds.
>
> Moreover in my case, out of the 12 drives not all are
> producing 12MB/sec.
> I've seen some of those performing as low as 45-90Kb/sec,
> which I think is
> unacceptable.  Isolating the bottle-neck, i guess, breaks the
> nut here.
>
> - Krishnan
>
> -----Original Message-----
> From: Matthew Huff [mailto:mhuff AT OX DOT COM]
> Sent: 15 March 2004 18:40
> To: NETWORKER AT LISTMAIL.TEMPLE DOT EDU
> Subject: Re: [Networker] Slow filer backups
>
>
> Due to the nature of the ufsdump basis of the NetApp NDMP backup,
> 12MB/sec isn't bad. An optimized legato parallelized stream would be a
> different metric.
>
> ----
> Matthew Huff           | One Manhattanville Rd
> Director of Operations | Purchase, NY 10577
> OTA LLC                | Phone: 914-460-4039
> http://www.otaotr.com  | Fax:   914-460-4139
>
> > -----Original Message-----
> > From: Davina Treiber [mailto:Treiber AT hotpop DOT com]
> > Sent: Monday, March 15, 2004 1:10 PM
> > To: Legato NetWorker discussion; Matthew Huff
> > Subject: Re: [Networker] Slow filer backups
> >
> >
> > Matthew Huff wrote:
> > > 12MB/sec isn't really that bad for LTO-1 drives.
> >
> > That's a matter of opinion. I'd say it's a bit poor. The
> > native speed is
> > 15 or 16 MB/s depending on brand, and it's not even up to
> > that figure.
> > In a well configured environment I have seen sustained write
> > speeds of
> > 25-30 MB/s. That's what I call not bad.

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