Hello,
I changed my setup like described in the wiki
(http://wiki.zmanda.com/index.php/How_To:Split_Dumps_Across_Tapes) to
split dumps accross tapes.
My problem is that I only get very low write performance with this
configuration now.
I am running amanda 2.5.2p1 on a Debian 5.0.5 (Lenny/i686) without a
holdingdisk and a LTO2 tape device with a 16 tape changer.
>From a log file before and after the change.
Normal backup run:
....
SUCCESS dumper backup.example.net <mybackup1> 20100720135703 0 [sec
140.366 kb 966790 kps 6887.6 orig-kb 966790]
SUCCESS taper backup.example.net <mybackup1> 20100720135703 0 [sec
140.684 kb 966816 kps 6872.2 {wr: writers 30214 rdwait 114.055 wrwait
24.330 filemark 2.053}]
SUCCESS dumper backup.example.net <mybackup2> 20100720135703 0 [sec
108.058 kb 889870 kps 8235.1 orig-kb 889870]
SUCCESS taper backup.example.net <mybackup2> 20100720135703 0 [sec
108.305 kb 889888 kps 8216.4 {wr: writers 27810 rdwait 84.511 wrwait
20.996 filemark 2.440}]
SUCCESS dumper backup.example.net <mybackup3> 20100720135703 0 [sec
124.763 kb 763210 kps 6117.2 orig-kb 763210]
SUCCESS taper backup.example.net <mybackup3> 20100720135703 0 [sec
125.878 kb 763232 kps 6063.2 {wr: writers 23852 rdwait 110.863 wrwait
10.540 filemark 4.280}]
SUCCESS dumper backup.example.net <mybackup4> 20100720135703 0 [sec
141.383 kb 660400 kps 4671.0 orig-kb 660400]
SUCCESS taper backup.example.net <mybackup4> 20100720135703 0 [sec
141.590 kb 660416 kps 4664.3 {wr: writers 20639 rdwait 129.368 wrwait
10.180 filemark 1.923}]
....
Split tape run:
....
CHUNK taper backup.example.net <mybackup1> 20100721132703 2023 0 [sec
5.061 kb 10208 kps 2016.8 {wr: writers 320 rdwait 0.318 wrwait 0.149
filemark 4.591}]
CHUNK taper backup.example.net <mybackup1> 20100721132703 2024 0 [sec
4.829 kb 10208 kps 2113.5 {wr: writers 320 rdwait 0.053 wrwait 0.151
filemark 4.622}]
CHUNK taper backup.example.net <mybackup1> 20100721132703 2025 0 [sec
5.191 kb 10208 kps 1966.2 {wr: writers 320 rdwait 0.095 wrwait 0.152
filemark 4.941}]
CHUNK taper backup.example.net <mybackup1> 20100721132703 2026 0 [sec
5.266 kb 10208 kps 1938.3 {wr: writers 320 rdwait 0.063 wrwait 0.153
filemark 5.047}]
CHUNK taper backup.example.net <mybackup1> 20100721132703 2027 0 [sec
5.248 kb 10208 kps 1945.0 {wr: writers 320 rdwait 0.059 wrwait 0.151
filemark 5.034}]
CHUNK taper backup.example.net <mybackup1> 20100721132703 2028 0 [sec
5.317 kb 10208 kps 1919.8 {wr: writers 320 rdwait 0.089 wrwait 0.152
filemark 5.072}]
CHUNK taper backup.example.net <mybackup1> 20100721132703 2029 0 [sec
5.306 kb 10208 kps 1923.6 {wr: writers 320 rdwait 0.105 wrwait 0.154
filemark 5.043}]
CHUNK taper backup.example.net <mybackup1> 20100721132703 2030 0 [sec
5.243 kb 10208 kps 1946.7 {wr: writers 320 rdwait 0.031 wrwait 0.155
filemark 5.053}]
....
With normal configuration the 500 GB full backup to tape took about
10-11 hours.
With the split tape config it took about 16 hours to backup 116 GB and
amanda ist still running to backup the other data.
Any advice or solution how to debug the problem (correct) and get normal
write performance with split tape dumps config?
Please let me know which configs can help to debug the problem.
--
Best regards
Dominik Schips
