scsidump performance

[hanshuebner]

Hi,

I'm using PiSCSI from the develop branch running on a RPi 3 using the 2.4 RaSCSI board. Target mode works fine and the performance is good. I have now tried to use initiator mode so that I can read and write real hard drives, but I have some issue with it. One problem is that more often than not, transfers to the disk fail, at arbitrary points in the operation, like this:

pdp-scsi 218_% sudo scsidump -t 2 -r -f rq0-ra81a-padded.hda
SCSI Target Emulator PiSCSI (Hard Disk Dump/Restore Utility)
Version 24.05 --DEVELOPMENT BUILD--  (May  3 2024 15:39:23)
Powered by XM6 TypeG Technology / Copyright (C) 2016-2020 GIMONS
Copyright (C) 2020-2024 Contributors to the PiSCSI project
[2024-05-05 09:28:58.307] [info] Detected Raspberry Pi 2/3
----------------------------------------
PiSCSI board ID is 7
----------------------------------------
Target device is 2:0
Vendor:      DEC
Product:     RZ25L    (C) DEC
Revision:    0008
Device Type: Direct Access
Removable:   No
Sectors:     1046205
Sector size: 512 bytes
Capacity:    510 MiB (535656960 bytes)
----------------------------------------

Starting restore
Restore file size: 535656960 bytes
0% (2048/1046205)
0% (4096/1046205)
0% (6144/1046205)
0% (8192/1046205)
0% (10240/1046205)
1% (12288/1046205)
1% (14336/1046205)
[...]
35% (366592/1046205)
35% (368640/1046205)
35% (370688/1046205)
Error: STATUS failed

With a couple of retries, I managed to completely write the image:

100% (1046205/1046205)
----------------------------------------
Transfered : 535656960 bytes [510MiB]
Total time: 1320 seconds (22 minutes
Average transfer rate: 50725 bytes per second (49 KiB per second)
----------------------------------------

The transfer speed, however, seems to be rather low.

Is this to be expected, or is there something wrong with my hardware?

Any help would be greatly appreciated. Thank you!
Hans