Yamaha CDR400t Specifications download pdf (Page 24)

4.1 How sensitive is the burning process?

Test it. Use the option −dummy to do an empty run of cdrecord. Do everything you would do otherwise and

watch if the burning process survives.

If you feed cdrecord directly from mkisofs, then disk intensive processes such as updating the locate database

lower the maximum flow rate and may corrupt the CD. You better check such processes are not started via

cron, at or anacron while you burn CD−Rs on older machines.

4.2 Has file fragmentation a bad impact on the throughput?

Fragmentation of files is usually so low that its impact isn't noticed. However, you can easily construct

pathological cases of fragmentation, which lower the throughput of your hard disks under 100 kbytes/second.

So don't do that. :−) Yes, files on a hard disk get fragmented over the years. The faster, the fuller the

filesystem is. Always leave 10% or 20% free space, and you should run fine with respect to writing CD−Rs.

If you're uncertain then look at the messages printed while booting. The percentage of fragmentation is

reported while checking the filesystems. You can check for this value with the very dangerous command

shell> e2fsck −n /dev/sda5 # '−n' is important!

[stuff deleted −− ignore any errors]

/dev/sda5: 73/12288 files (12.3% non−contiguous)

In this example the fragmentation seems to be very high −− but there are only 73 very small files on the

filesystem. So the value is not alarming.

There is an experimental utility called e2defrag to defragment extended−2 filesystems. The current version

does not work reliable enough to use it even for private environments. If you really want to defragment your

filesystem, make a backup copy (better: two copies), practice restoring the data, then create a new filesystem

(that will destroy the old) and restore the data. This sketch is currently the safest technique.

4.3 Is it possible to store the CD−image on an

UMSDOS−filesystem?

Yes. The only filesystem that isn't reliable and fast enough for writing CD−ROMs from is the network

filesystem (NFS). I used UMSDOS myself to share the disk−space between Linux and DOS/Win on a PC

(486/66) dedicated for writing CD−ROMs.

CD−Writing HOWTO

4.1 How sensitive is the burning process? 21

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Yamaha CDR400t Specifications Page 24