Fabio Comolli wrote: > Burning CDs or blanking CD-RWs as root user gives no warnings; as > normal user always gives: > > cdrecord: Cannot allocate memory. WARNING: Cannot do mlockall(2). > cdrecord: WARNING: This causes a high risk for buffer underruns. > cdrecord: Operation not permitted. WARNING: Cannot set RR-scheduler > cdrecord: Permission denied. WARNING: Cannot set priority using setpriority(). > cdrecord: WARNING: This causes a high risk for buffer underruns. > > This happens either running cdrecord directly or through k3b. So far I > got no toasters: should I consider this warnings harmless? Depends. Do you have a drive with "Burn Free"? ("This may be called: Sanyo BURN-Proof, Ricoh Just-Link, Yamaha Lossless-Link or similar." -- the cdrecord man page.) If you do, then the drive should be able to recover from buffer under-runs anyway. You can check by running cdrecord -prcap | grep Buffer-Underrun-Free and looking for Does support Buffer-Underrun-Free recording This is assuming you still have the word "burnfree" in the default place in /etc/cdrecord.conf. If you haven't touched that file, then it should be there. If you don't have "Burn Free", then it depends on such things as how fast you're recording, how large an on-board buffer you have (= cache: dmesg | grep CD-R/RW should tell you), and how much else the system is doing. The basic problem is that if the CD recorder runs out of data, then it needs "burn free" to be able to pause a recording. So one without "burn free" *needs* to have data spooled to the drive constantly. For example, my DVD±RW has hdc: ATAPI 48X DVD-ROM DVD-R-RAM CD-R/RW drive, 2048kB Cache, UDMA(33) and a maximum write speed of 8467 kB/s, which implies that the cache is capable of handling delays of nearly a quarter of a second at top speed. Unless it's *very* heavily laden, of the time, a Linux box will respond faster than a quarter of a second (if it didn't, you'd notice it in X) and a recent one should be able to sustain 8 MB/s. So I don't really need burnfree. As it is, I certainly don't worry... The worst case scenario is that you'll get a dud CD, yes. As for what the error messages mean, mlockall is the application wanting to "lock" its virtual memory into fast real memory, so it doesn't get paged to slow disk, and wanting "real-time"-like priority, so it gets to run before all other processes. Only root is allowed to set such things, by default. Hope this helps, James. -- E-mail address: james | DON'T be put off by "horror stories" spread by @westexe.demon.co.uk | others. People who talk about death and serious | injury are very rarely the ones who have actually | suffered such things. -- Adrian Plass