lot of things can slow down an NDMP backup.
First, make sure you're using a locally attached tape drive, not
three-way NDMP (where backups are sent via IP to another system). The
other will work, but not if you want any performance. ;)
Second, the layout of the volume can really affect your performance. If
your volume consists of only a few spindles, or if they're all from the
same disk shelf, etc.... Any of those can make a volume that won't
supply you with enough data to make that LTO-2 tape drive happy.
Third, the content of the filesystem really affects performance as well.
Small files are your enemy. The more files you have per GB, the slower
your performance will be.
Finally, if your NetApp is sending only, say 15 MB/s, that isn't going
to stream that LTO-2. The LTO-2 ends up spending all its time
backhitching and shoeshing, and your 15 MB/s turns into only a few MB/s.
This means that it becomes the next bottleneck.
So, do what you can to layout the volume well. As to the files, they
are what they are. Not much you can probably do there. Finally, if you
want tape performance to exactly match what's coming out of the NetApp,
consider a virtual tape library. NDMP and VTLs are a match made in
heaven. You can give every filer as many virtual tape drives as it
needs to do its local backup, without actually purchasing dozens of tape
W. Curtis Preston
Author of O'Reilly's Backup & Recovery and Using SANs and NAS
VP Data Protection
[mailto: XXXX@XXXXX.COM ] On Behalf Of Raju
Sent: Thursday, January 25, 2007 9:02 AM
Subject: Re: [C.A.S.] NDMP backups I/O bottleneck?
have you tried storage pool in between backup server and tape. I am not
sure it works in netbackup. Same issue we have. We have lots of files
on almost all netapp volume. average file size is very less.
We use Tivoli storage manager so we configured LAN back which I feel is
better in case of lots of smaller file size. Backup server first backup
files in diskstorage pool and once backup completed then moves from
storage pool to tape in offline manner so primary netapp files doesn't
remain busy alltime.
please check if diskstorage pool posibility exists in netbackup
On Jan 17, 9:08 am, "Mike" < XXXX@XXXXX.COM > wrote:
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