[lug] writeable CD curiosity

[David Anselmi]

D. Stimits wrote:
[...]
> Another possibility that I wonder about only for curiosity, and not 
> necessarily for logging, is the concept of a RAID 1 where the partitions 
> being mirrored are (a) a ram-based filesystem and (b) a rewriteable CD 
> system...if power fails and ram is flushed, then the CD is used for 
> rebuilding the array; or while power runs, the CD could be ejected and 
> saved, a new CD added, and have it automatically rebuild the array via 
> copy from ram to CD-RW. What are the hardware limitations to this?

If you're going to write to the CD-RW as though it were a hard drive, 
why not use a hard drive?  What you describe seems to add nothing but 
poor performance and (relatively) short media life.

OTOH, if you log to a ramdisk it would be easy to hook cdrecord into 
your logrotate jobs so that current logs are kept on disk and old logs 
on CD.  Then use CD-R instead of CD-RW and they won't be erasable.

But do you really want to lose the most recent X minutes of logs when 
your machine crashes?

I think that what you want is a UDF filesystem.  There is some support 
for this in Linux, perhaps even more in the 2.6 kernel.  It probably 
doesn't work like you've described but it might be close enough.

Dave