60GB, 4hrs....sounds about right for one spindle.

Hi all,

I'm trying to understand why amanda (v2.6.0p2, on RHEL4) is taking so
long to backup just 60 Gb, the actual taping appears to only take a
fraction of the time. I've double checked that compression is not
enabled and in the report (see below) the estimation takes a grand total
of 0 minutes. Actually writing the data to tape only took 35 minutes,
the dump time was over 4 hours, over 11 hours without using a holding
disk (holdingdisk never).

The tape server and client are one and the same, it's backing up a local
filesystem.

I've used amplot to try and get some sense of where the problem lies,
but the graphs aren't very enlightening:
Graph 1. http://www.box.net/shared/6ufte4udmq
Graph 2. http://www.box.net/shared/j5f7gn0s2n (no holding disk)

I'd really appreciate some pointers as to where to look next.



These dumps were to tape lib-01.
The next 10 tapes Amanda expects to use are: 10 new tapes.
The next 10 new tapes already labelled are: lib-02, lib-03, lib-04,
lib-05, lib-06, lib-07, lib-08, lib-09, lib-10, lib-11.


STATISTICS:
                         Total       Full      Incr.
                       --------   --------   --------
Estimate Time (hrs:min)    0:00
Run Time (hrs:min)         4:33
Dump Time (hrs:min)        4:32       4:32       0:00
Output Size (meg)       58139.9    58139.9        0.0
Original Size (meg)     58139.9    58139.9        0.0
Avg Compressed Size (%)     --         --         --
Filesystems Dumped            1          1          0
Avg Dump Rate (k/s)      3647.6     3647.6        --

Tape Time (hrs:min)        0:25       0:25       0:00
Tape Size (meg)         58139.9    58139.9        0.0
Tape Used (%)              29.0       29.0        0.0
Filesystems Taped             1          1          0

Chunks Taped               5814       5814          0
Avg Tp Write Rate (k/s) 39088.7    39088.7        --

USAGE BY TAPE:
 Label           Time      Size      %    Nb    Nc
 lib-01          0:25    58140M   29.0     1  5814



DUMP SUMMARY:
                                      DUMPER STATS               TAPER
STATS
HOSTNAME     DISK        L ORIG-MB  OUT-MB  COMP%  MMM:SS   KB/s MMM:SS
KB/s
-------------------------- -------------------------------------
-------------
127.0.0.1    /foo 0   58140   58140    --   272:02 3647.6  25:23 39088.7

(brought to you by Amanda version 2.6.0p2)

I've attached my amanda.conf, the particularly relevant bits are
repeated here:

[...]
flush-threshold-dumped  100
flush-threshold-scheduled       100
taperflush      0
[...]
runtapes 10     # number of tapes to be used in a single run of amdump
tpchanger "chg-zd-mtx"     # the tape-changer glue script
tapedev "tape:/dev/nst0"   # the no-rewind tape device to be used
[...]
tapetype IBM-Ultrium3582
[...]
holdingdisk hd1 {
   comment "main holding disk"
   directory "/usr/local/backup/dumps"
   use 25Gb
   chunksize 2 Gb
}
[...]
define tapetype IBM-Ultrium3582 {
   comment "IBM Ultrium 3582 (hardware compression on)"
   length 200704 mbytes
   filemark 0 kbytes
   speed 32409 kps
}
[...]
define dumptype high-tar-span {
   root-tar
   program "GNUTAR"
   tape_splitsize 2 Gb
   comment "tape-spanning partitions dumped with tar"
   priority high
}
[...]
define interface local {
   comment "a local disk"
   use 8000 kbps
}

disklist:
127.0.0.1 /foo high-tar-span

Thanks in advance,

--
-Jamie L. Penman-Smithson <jpenman.smithson AT gmail DOT com>

--
"Genius might be described as a supreme capacity for getting its possessors
into trouble of all kinds."
-- Samuel Butler