Re: ISM nsr block size
The backups via onbar/ism or onbar/<insert_your_storage_manager_here>
will always be slower for a single device. ontape opens a file
descriptor on the tape and writes directly to it, so there is little
overhead. But this means that the tape device is dedicated to ontape,
while ISM allows one to use the tape device for other backups.
If you want to backup faster using onbar/ism, break-up your backup
into separate sections using the parallel command, and point each
onbar command to a different tape device:
onbar -b -d rootdbs physdbs # goes to tape device 1
onbar -b -d physdbs datadbs1 # goes to tape device 2
onbar -b -d datadbs2 datadbs3 # goes to tape device 3
etc.
In ISM you can have a maximum of 4 devices/connections. With other
storage managers you can use more devices/connections.
I believe nsradmin adjusts the block size, but its been years since I
ran nsradmin. onbar does not adjust the block size. Hope this
information helps.
Brice Avila
Minneapolis, Minnesota
bickel@zonnet.nl (Bickel) wrote in message news:<59f2c4de.0305120123.2be333c2@posting.google.com>...
> Hai,
>
> Does anybody know how to ajust the block size on a ism device?
> via nsradmin i can only see, not ajust this size but its always not
> visible.
>
> The backups via onbar/ism are always a bit slower than ontape so maybe
> its the block size?
>
> Bickel