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
