I have a Knoppix 4.0 DVD that came bundled with a computer magazine. The DVD seems to run fine. Nevertheless I wanted to check data integrity by entering "testcd" at boot. The computer began checking files, but after a while the DVD drive was spinning down and the screen turned dark. When I pressed a key, the screen came back, and I could see that the computer was testing the KNOPPIX2 file when it got stuck. I tried testcd with two different computers and never got beyond the KNOPPIX2 file.
Can anybody confirm this issue? Is "testcd" supported by the DVD versions of Knoppix?
Dell PowerEdge R630 Server 2x E5-2680 V4 = 28 Cores S130 32GB RAM NEW 480GB SSD
$197.99
Dell PowerEdge R630 Server 2x E5-2640v3 2.60Ghz 16-Core 64GB H330
$182.65
Dell Poweredge R630 Server 2x E5-2620 V4 =16 Cores | S130 | 32GB RAM | 2x trays
$159.99
Dell PowerEdge R720xd 26HDD 300gb 2.5-inch E5-2697 X 2CPU 384RAM 7.2 Tb HDD 
$180.00
Dell Poweredge R730xd 12 Bay LFF 2x SFF 2x E5-2680v3 2.5ghz H730p No Ram No HDD
$219.99
Dell Poweredge R730xd LFF 14-Bay 2U Server | Choose Your CPU & RAM Config
$489.99
Dell PowerEdge M620 Blade Server 2 x Xeon e5 2665 8 x 16 GB(128) RAM - No HD
$44.99
DELL PowerEdge R430 8SFF 2x E5-2680v4 2.4GHz =28 Cores 32GB H730 4xRJ45
$226.00
DELL PowerEdge R730XD Server 2x E5-2680v3 2.5GHz =24 Cores 32GB H730 4xRJ45
$267.00
DELL PowerEdge R630 8SFF Server 2x E5-2697v3 2.6GHz =28 Cores 128GB H730 4xRJ45
$352.00