Differences

This shows you the differences between two versions of the page.

Link to this comparison view

Last revision Both sides next revision
kernel_messages [2018/04/09 02:20]
beandog created
kernel_messages [2018/04/09 02:22]
beandog
Line 28: Line 28:
 Apr  9 02:19:36 tux kernel: blk_update_request:​ I/O error, dev sr0, sector 12887552 Apr  9 02:19:36 tux kernel: blk_update_request:​ I/O error, dev sr0, sector 12887552
 Apr  9 02:19:36 tux kernel: Buffer I/O error on dev sr0, logical block 1610944, async page read Apr  9 02:19:36 tux kernel: Buffer I/O error on dev sr0, logical block 1610944, async page read
 +</​code>​
 +
 +When you put a disc in the drive, there'​s a [[udev]] rule that runs [[cdrom_id]] to get the device variables (which is an ingenious program, I might add).
 +
 +You can see what udev is doing at ''/​lib64/​udev/​rules.d/​60-cdrom_id.rules''​
 +
 +It's tiny and mostly self-explanatory,​ so I'll post the whole thing here:
 +
 +<​code>​
 +# do not edit this file, it will be overwritten on update
 +
 +ACTION=="​remove",​ GOTO="​cdrom_end"​
 +SUBSYSTEM!="​block",​ GOTO="​cdrom_end"​
 +KERNEL!="​sr[0-9]*|xvd*",​ GOTO="​cdrom_end"​
 +ENV{DEVTYPE}!="​disk",​ GOTO="​cdrom_end"​
 +
 +# unconditionally tag device as CDROM
 +KERNEL=="​sr[0-9]*",​ ENV{ID_CDROM}="​1"​
 +
 +# media eject button pressed
 +ENV{DISK_EJECT_REQUEST}=="?​*",​ RUN+="​cdrom_id --eject-media $devnode",​ GOTO="​cdrom_end"​
 +
 +# import device and media properties and lock tray to
 +# enable the receiving of media eject button events
 +IMPORT{program}="​cdrom_id --lock-media $devnode"​
 +
 +# ejecting a CD does not remove the device node, so mark the systemd device
 +# unit as inactive while there is no medium; this automatically cleans up of
 +# stale mounts after ejecting
 +ENV{DISK_MEDIA_CHANGE}=="?​*",​ ENV{ID_CDROM_MEDIA}!="?​*",​ ENV{SYSTEMD_READY}="​0"​
 +
 +KERNEL=="​sr0",​ SYMLINK+="​cdrom",​ OPTIONS+="​link_priority=-100"​
 +
 +LABEL="​cdrom_end"​
 </​code>​ </​code>​

Navigation