Can you try the following command:

$ time dd if=/dev/i500-lto4-tape1 bs=32k of=/dev/i500-lto4-tape2

Put an amanda tape in /dev/i500-lto4-tape1 and a new tape in /dev/i500-lto4-tape2
Run the command a few times.

You can also try to use bigger block size 128k-256k

Jean-Louis

On 03/14/2012 09:04 AM, Sven Rudolph wrote:
Jean-Louis Martineau<[email protected]>  writes:

Try to set a larger value for 'device-output-buffer-size'.
Tried, didn't really help:

   device-output-buffer-size       128m

(I append the nearly-complete amanda.conf below.)

Amanda now continues with the following tape, beacuse I set partsize:

   define tapetype TERTIARY {
        LTO4
        #part-size 0
        part-size 5g
   }

(Originally I wanted a mode where it doesnt split in parts but only
splits on LEOM. Worked with amanda 3.2.x and erlier, I didn't get it
running on 3.3.x)

This change also shows that sometimes parts are written fast:

   Wed Mar 14 13:22:00 2012: amvault: Building type SPLIT_FILE header of 
32768-32768 bytes with name='fileserver' disk='/data' dumplevel=0 and 
blocksize=32768
   Wed Mar 14 13:22:49 2012: amvault: Building type SPLIT_FILE header of 
32768-32768 bytes with name='fileserver' disk='/data' dumplevel=0 and 
blocksize=32768
   Wed Mar 14 13:38:49 2012: amvault: Building type SPLIT_FILE header of 
32768-32768 bytes with name='fileserver' disk='/data' dumplevel=0 and 
blocksize=32768
   Wed Mar 14 13:50:45 2012: amvault: Building type SPLIT_FILE header of 
32768-32768 bytes with name='fileserver' disk='/data' dumplevel=0 and 
blocksize=32768


So it works now, but still very slow. Will take more than 2 weeks. And
probably does brilliant shoeshining.

        Sven


On 02/27/2012 11:07 AM, Sven Rudolph wrote:
(I sent this message on Feb 23, but it didn't appear on the list. I
resend it here without the logfiles attached. Maybe they were too
large.)

Hello,

I am trying to setup amvault for tape-to-tape duplication.

My problem is that the write speed is very low (about 12 MB/s) whereas
the native write speed usually is about 115 MB/s:

    PART taper Set1K-2011-01 2 fileserver /backup 20120101030850 1/-1 0 [sec 
16429.995803 bytes 208375369542 kps 12385.369628]
    DONE taper fileserver /backup 20120101030850 1 0 [sec 16430.000000 bytes 
208375369542 kps 12385.366464 orig-kb 310011210]

The amreport mail message finally says:

    Avg Tp Write Rate (k/s)  14148.8    14148.8        --

    USAGE BY TAPE:
      Label               Time         Size      %  DLEs Parts
      Set1K-2011-01      14:36      726591M   94.4     3     3


The tape drives ar IBM FC LTO-4, each connected to its own 4Gb FC
port. Running dd's to each drive in parallel I do not see a
bottleneck:

    $ dd if=/dev/i500-lto4-tape1 bs=32k of=/dev/null bs=32k count=1000000
    1000000+0 records in
    1000000+0 records out
    32768000000 bytes (33 GB) copied, 281.63 s, 116 MB/s

    $ dd if=/dev/i500-lto4-tape2 bs=32k of=/dev/null bs=32k count=1000000
    1000000+0 records in
    1000000+0 records out
    32768000000 bytes (33 GB) copied, 310.629 s, 105 MB/s

I tried to strace the processes/threads:

    # ls -l /proc/21570/fd
    total 0
    lrwx------ 1 backup backup 64 Feb 23 14:07 0 ->   /dev/pts/6
    lrwx------ 1 backup backup 64 Feb 23 14:07 1 ->   /dev/pts/6
    l-wx------ 1 backup backup 64 Feb 23 14:07 10 ->   
/var/log/amanda/server/MonthlySet1/amvault.20120223133643.debug
    lrwx------ 1 backup backup 64 Feb 23 13:38 2 ->   /dev/pts/6
    lrwx------ 1 backup backup 64 Feb 23 14:07 3 ->   anon_inode:[eventfd]
    lrwx------ 1 backup backup 64 Feb 23 14:07 5 ->   /dev/nst3
    lr-x------ 1 backup backup 64 Feb 23 14:07 6 ->   pipe:[5827058]
    l-wx------ 1 backup backup 64 Feb 23 14:07 7 ->   pipe:[5827058]
    lrwx------ 1 backup backup 64 Feb 23 14:07 8 ->   /dev/nst2
    # ls -l /proc/21570/task/
    total 0
    dr-xr-xr-x 5 backup backup 0 Feb 23 13:45 21570
    dr-xr-xr-x 5 backup backup 0 Feb 23 13:45 21573
    dr-xr-xr-x 5 backup backup 0 Feb 23 13:45 21800
    dr-xr-xr-x 5 backup backup 0 Feb 23 13:45 21801

My summary of whats going on (full logs attached below):

14:18:17.778803    the reader process starts reading 32k blocks
14:18:18.018007    the writer process starts writing
14:18:18.017894    the reader process doesnt show all the futex calls
14:18:18.285803    the writer stopps writing
14:18:18.295847    the reader stops reading
14:18:24.281473    the writer starts writing
14:18:24.281608    the reader starts reading
...

So ... something seems to be to slow so that the tape drives don't
keep streaming.

I am using Amanda 3.3.0 on Debian.

Any ideas, suggestions, ... ?


-----
Here my amanda.conf:


org "MonthlySet1"             # your organization name for reports
mailto "ambackup"     # space separated list of operators at your site
dumpuser "backup"     # the user to run dumps under

inparallel 15           # maximum dumpers that will run in parallel
netusage  130000        # maximum net bandwidth for Amanda, in KB per sec
maxdumps 1              # amount of parallelism per client

dumporder "BSSTSsSsSS"

etimeout 3600           # time per disk on a client planner waits for estimates
dtimeout 20000          # time the dumper waits for input data

dumpcycle 4 weeks       # the number of days in the normal dump cycle
runspercycle 5
tapecycle 64 tapes      # the number of tapes in rotation

bumpsize 20 MB          # minimum savings (threshold) to bump level 1 ->  2
bumpdays     1          # minimum days at each level
bumpmult     4          # threshold = bumpsize * (level-1)**bumpmult

runtapes 18             # explained in WHATS.NEW

device-output-buffer-size       128m

displayunit     "m"

define changer i500-changer {
        tapedev "chg-robot:/dev/i500-changer"
        property "tape-device" "0=tape:/dev/i500-lto4-tape"
        property "use-slots" "1-22"
        device_property "LEOM" "yes"
}
tapedev         "i500-changer"

define changer i500-changer-vault {
        tapedev "chg-robot:/dev/i500-changer"
        property "tape-device" "1=tape:/dev/i500-lto4-tape2"
        property "use-slots" "87-108"
        device_property "LEOM" "yes"
}

amrecover_changer "changer"

autoflush off
#taperalgo largestfit
taperalgo largest

flush-threshold-dumped  300
taperflush      0
# # flush-threshold-scheduled>= flush-threshold-dumped
# # flush-threshold-scheduled>= taperflush
flush-threshold-scheduled       500


tapetype LTO4
labelstr 
"^((Set1-(Jan|Feb|Mar|Apr|May|Jun|Jul|Aug|Sep|Oct|Nov|20..)-)|(Set1K-20..-)).*$"
     # label constraint regex: all tapes must match

columnspec 
"HostName=0:8,Disk=1:18,DumpRate=1:6,OrigKB=1:8,OutKB=1:8,TapeRate=1:6"

reserve 1              # holding-disk space reserved for non-full backups

holdingdisk holdingdisk1 {
        directory "/var/spool/amanda/1/1m"
        use -1GB
        chunksize 1 GB
}
# ... more holdingdisks

infofile "/var/lib/amanda/MonthlySet1/curinfo"        # database filename
logdir  "/var/log/amanda/MonthlySet1/"        # log filename

indexdir "/var/lib/amanda/MonthlySet1/index"

define tapetype LTO4 {
     comment "LTO-4"
     length 770000 mbytes
#    length 790000 mbytes
     filemark 0 kbytes
     speed 115000 kps
     lbl-templ "/etc/amanda/WeeklySet1/LTO-label.ps"
}

define tapetype TERTIARY {
        LTO4
        #part-size 0
        part-size 5g
}


# ... dumptypes ...



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