Hi William,
Could you tell us please:
- What tape library are you using? There are various LTO-4 tapetype definitions
depending on your tape library.
- What is the size of the holding disk "hd1"? How much free space is available
on it?
I'd try increasing the tape_splitsize to 200Gb (assuming you have this amount
of free space available on the /scratch filesystem):
define dumptype user-tar-span {
#holdingdisk no
root-tar
tape_splitsize 200 Gb
split_diskbuffer "/scratch/"
#fallback_splitsize 8 Gb
priority medium
}
Best,
Valeriu
On Mon, Feb 22, 2010 at 10:11:01AM -0800, William Taylor wrote:
> I seem to be having some issues with amanda getting data off my drives in a
> reasonable time.
> using dd reading off my drives and writing to tape I get around 120mbs to the
> LTO4 drive.
> When using amanda however this number fluctuates quite a bit. At times I have
> seen it write to tape
> at around 110mbs but it's usually around 40 or so.
>
> I have tried several different configuration options and none seem to really
> improve the situation.
>
> I am using amanda to do local backups.
> I have a bunch of large (+2TB) netapp dumps on a 24 disk 16T raid5 array
> connected to a 3Ware.
> I have also configured a 14 disk netapp shelf with 15k scsi drives striped
> with software raid connected via a 2GB fcal to use as
> a scratch disk to break up dumps or to use as a holding disk.
>
>
> Can anyone recommend amanda config options that would work with my setup?
> So far it seems that best results are achieved without using the holding disk.
> I have tried setting the tape_splitsize to 4Gb and fallback_splitsize to 8Gb
> with no
> real change in performance. I have 12GB of memory.
>
>
> Heres the relevant bits I have so far:
>
> netusage 100 mbps
> device_output_buffer_size 1 Gb
> tapedev "tape:/dev/nst0"
> device_property "BLOCK_SIZE" "1024k"
>
> holdingdisk hd1 {
> comment "main holding disk"
> directory "/scratch/"
> use -100 Mb
> chunksize 80Gb
> }
>
> define tapetype LTO4 {
> comment "Dell LTO4 800Gb - Compression Off"
> length 802816 mbytes
> filemark 0 kbytes
> speed 120 mbps
> blocksize 1024 kbytes
> }
>
> define dumptype user-tar-span {
> #holdingdisk no
> root-tar
> tape_splitsize 80 Gb
> split_diskbuffer "/scratch/"
> #fallback_splitsize 8 Gb
> priority medium
> }
>
>
> If I need to provide anymore info let me know.
>
> Thanks,
> William
>
