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Accessing CD/DVD drive brings system to a crawl

Ubuntu 9.10 64 bit
Dell XPS 8000
i7-860 2.8 GHz quad core
8 GB RAM
150 GB 10K RPM SATA drive with / /home and swap
750 GB and 1 TB SATA drives for data
nVidia GeForce GT220 1 GB video card

I guess this is best asked as a hardware question so here goes...

When I place a blank CD or DVD in the drive and the machine attempts to recognize it, everything else seems to slow to a halt. For example Firefox or other programs which are running will sometimes gray out.

When I begin to burn a CD or DVD with Nero or Brasero the machine will bog down for several seconds as the process starts.

And, most annoying of all - if I have a bad CD or DVD which the machine cannot read - the entire machine slows to the point of being unusable for several minutes until it finally gives up trying to read the bad media. I have observed the operation of the machine with System Monitor during these slowdowns and I do not see any resource being used up.

I have plenty of CPU available
I have plenty of memory available

Why is the machine becoming unresponsive?

TIA,

Ken

Hi,

What happens when you open your burn application then place the media in the drive?

It sounds like a 'udev' & 'HAL' issue.

:hattip:

Same thing - some seconds of unresponsiveness while the media is being recognized.

Hi,

Do you get control back when you perform the action within the burn application?

:hattip:

Not sure what you mean onebuck. Regardless of how or when I insert the media the PC stalls as the media is recognized and, for a longer period, as the burn process begins.

Ken

I used to have this exact problem on my older machine, and from what I recall from the documentation at the time regarding the CDRW tools, it was normal. The docs, IIRC, said to "try not to do much with the machine while the burning was happening."
However, by current machine is more 'able' than my older one, and sometime between "then" and "now", this problem has gone away.
The OP's machine doesn't look like a slouch to me :) so I would think that it too should be able to burn a disc and still remain operational while doing so.

Two thoughts:

1) Ubuntu (or its burning tools) wouldn't be geared up to "suck up all the machine while burning", would they?

2) Is there a cache setting that affects CD/DVD write performance? There *is* a setting in the kernel for "number of write buffers", but IIRC it's only for UDF packet-writing. I'll look at my kernel config to see what I'm talking about :p and post back shortly.

Right, OK, so I've got my kernel xconfig dialog up here, and in:

Device Drivers --> Block devices --> Packet writing on CD/DVD media

there is the sub-option "(xxxx) Free buffers for data gathering".

I'm not sure what the default is, and I'm also not sure that this applies in any way to CD/DVD writing "in general" or just specifically to "packet-writing", but I have mine set to 1024 64k buffers.

Sorry if this doesn't help; not sure what else to consider :scratch:

Sasha

Can you let us see the output of: cat /etc/fstab and then: cat /etc/mtab

Also, although this may not work because Ubuntu 9.10 defaults to using UUID's for device names, but it may be worth a try - please post the output, if any, of:

sudo cat /var/log/messages | grep hdc

Quote:

ken@taylor12:~$ cat /etc/fstab
# /etc/fstab: static file system information.
#
# Use 'blkid -o value -s UUID' to print the universally unique identifier
# for a device; this may be used with UUID= as a more robust way to name
# devices that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point> <type> <options> <dump> <pass>
proc /proc proc defaults 0 0
/dev/sda1 / ext3 errors=remount-ro 0 1
/dev/sda3 /data ext3 defaults 0 2
/dev/sda5 /home ext3 defaults 0 2
/dev/sdb1 /quitelarge ext3 defaults 0 2
/dev/sdc1 /veryhuge ext3 defaults 0 2
/dev/sda6 none swap sw 0 0
/dev/scd0 /media/cdrom0 udf,iso9660 user,noauto,exec,utf8 0 0

ken@taylor12:~$ cat /etc/mtab
/dev/sda1 / ext3 rw,errors=remount-ro 0 0
proc /proc proc rw 0 0
none /sys sysfs rw,noexec,nosuid,nodev 0 0
none /sys/fs/fuse/connections fusectl rw 0 0
none /sys/kernel/debug debugfs rw 0 0
none /sys/kernel/security securityfs rw 0 0
udev /dev tmpfs rw,mode=0755 0 0
none /dev/pts devpts rw,noexec,nosuid,gid=5,mode=0620 0 0
none /dev/shm tmpfs rw,nosuid,nodev 0 0
none /var/run tmpfs rw,nosuid,mode=0755 0 0
none /var/lock tmpfs rw,noexec,nosuid,nodev 0 0
none /lib/init/rw tmpfs rw,nosuid,mode=0755 0 0
/dev/sdc1 /veryhuge ext3 rw 0 0
/dev/sda3 /data ext3 rw 0 0
/dev/sdb1 /quitelarge ext3 rw 0 0
/dev/sda5 /home ext3 rw 0 0
none /proc/fs/vmblock/mountPoint vmblock rw 0 0
binfmt_misc /proc/sys/fs/binfmt_misc binfmt_misc rw,noexec,nosuid,nodev 0 0
gvfs-fuse-daemon /home/ken/.gvfs fuse.gvfs-fuse-daemon rw,nosuid,nodev,user=ken 0 0
/dev/sdd1 /media/seagate320-2 ext3 rw,nosuid,nodev,uhelper=devkit 0 0

I do not find anything in messages.

Ken

Okay wrt the messages you might try grepping for 'scd0' rather than 'hdc' or alternatively look at about 2 to 5 seconds for the equivalent of my output:

Quote:

deb503:~# cat /var/log/messages | grep hdc
Jan 31 13:31:23 localhost kernel: [ 2.788109] hdc: MATSHITADVD-RAM UJ-835S, ATAPI CD/DVD-ROM drive
Jan 31 13:31:23 localhost kernel: [ 3.136305] hdc: UDMA/33 mode selected
Jan 31 13:31:23 localhost kernel: [ 4.003742] hdc: ATAPI 24X DVD-ROM DVD-R-RAM CD-R/RW drive, 2048kB Cache

Dependent upon the nature of the CD's and/or DVD's you expect to read, i.e. if they are FAT formatted data disks -RW, it might help to remove the 'utf8' which converts 16 bit Unicode characters on CD to UTF-8 on FAT file systems, according to my reading of the 'mount' man page, and remove the 'exec' option which allows the execution of binaries on the CD/DVD. Whilst I must admit that I doubt that removing these options will have little effect on a blank CD, I only mention them since I don't have them enabled on my machine which is working fine, although I must admit the I use k3b (and kde) and I only have to wait a couple of seconds for my drive to recognise blank media.

Cheers
Rich