On 24/10/14 08:30, Jean-Francois Malouin wrote:
> Stepping in, I miss the earlier comments so maybe this is not
> appropriate or OT, in which case just toss me in the dust bin.
>
> Your length and speed are way off.
>
> This is my tapetype for a HP Ultrium LTO-5
>
> define tapetype tape-lto5 {
> comment "Created by amtapetype; compression disabled"
> length 1480900608 kbytes
> filemark 3413 kbytes
> speed 107063 kps
> blocksize 2048 kbytes
> part-size 100gb
> part-cache-max-size 100gb
> part-cache-type disk
> part-cache-dir "/holddisk"
> }
>
> In this case, amtapetype disappointedly reported only ~100MBs (native
> speed per specs is 140MBs) but in my local setup I frequently see
> values up to 300MBs with 'averaged xfer rate' around the specs value,
> eg, see the attached munin graph of my holdding disk performance from
> last night run, the green line is data from the holdding disk to the
> tape. LTO-5 will stream from 40MBs (I think) to 150Mbs, lower than
> that you're shoe-shinning.
>
> If the data xfer from the holdding disk to the drive can sustain the max
> xfer data rate to the drive (140MBs) this suggest you have a dud or
> experiencing other hardware issues. I would test the hardware directly
> without amanda in the way using native OS tool, dd or whatever you
> fancy.
>Here are two files from the daily dump: 1021882368 Oct 22 21:02 slot4/00076.rook._data_data0.1 1094219252 Oct 17 20:32 slot7/00070.scion._home.1 Here's a tar directly to tape (run as amanda user): $ time tar cvf /dev/rmt/0b slot7/00070.scion._home.1 slot4/00076.rook._data_data0.1 slot7/00070.scion._home.1 slot4/00076.rook._data_data0.1 real 0m29.755s user 0m0.656s sys 0m5.063s $ echo '((1094219252+1021882368)/1000/1000)/29.755' | bc -l 71.11751369517728112922 Some speed tests with dd: $ dd if=/dev/zero of=/data/backup/amanda/file1 bs=1024k count=2048 2048+0 records in 2048+0 records out 2147483648 bytes (2.1 GB) copied, 1.34568 s, 1.6 GB/s $ time dd if=/data/backup/amanda/file1 of=/dev/rmt/0b bs=512k count=4000 4000+0 records in 4000+0 records out 2097152000 bytes (2.1 GB) copied, 13.4122 s, 156 MB/s real 0m13.427s user 0m0.015s sys 0m1.519s $ time dd if=/data/backup/amanda/file1 of=/dev/rmt/0b bs=512k count=4000 4000+0 records in 4000+0 records out 2097152000 bytes (2.1 GB) copied, 13.4404 s, 156 MB/s real 0m13.456s user 0m0.014s sys 0m1.471s $ time dd if=/dev/zero of=/dev/rmt/0b bs=512k count=4000 4000+0 records in 4000+0 records out 2097152000 bytes (2.1 GB) copied, 8.24686 s, 254 MB/s real 0m8.262s user 0m0.011s sys 0m0.297s $ time dd if=/dev/zero of=/dev/rmt/0b bs=512k count=4000 4000+0 records in 4000+0 records out 2097152000 bytes (2.1 GB) copied, 8.1345 s, 258 MB/s real 0m8.150s user 0m0.011s sys 0m0.299s Writing directly to tape with dd if much faster than reading from filesystem and writing to tape. In which case maybe I probably have a controller type issue?
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