Bill Davidsen <davidsen@xxxxxxx> writes: > Ferenc Wagner wrote: > >> I use an FC SAN, which provides multiple pathes to multiple LUNs. >> These all come up as different sd* devices, exhausting single letter >> names. I mean they are a LOT. Using the md mulitpath driver >> everything works perfectly, no problems there. However, during boot, >> the kernel tries to read the partition table from each device, >> spitting out hundreds of lines of error messages: most of the devices >> aren't even readable, and those which are, don't contain a valid >> partition table. They never will. So I'd like to disable partition >> detection, because these messages overflow the kernel message buffer, >> depriving syslog of gathering any useful boot messages, and also >> needlessly lengthening the boot process. (Of course the noise alone >> is disturbing enough when one tries to troubleshoot a boot problem.) >> However, looking at the kernel sources didn't give me any hint. Is >> this possible to disable at all? >> >> (Please Cc me, I'm not on the list.) > > After reading some code, I didn't see any boot or module load options > you can use to prevent that, I think you may want to increase buffer > size to hold the messages and use "grep -v" to create a sanitized > dmesg. If you can give an example of the error message you see I can > look again. > > Don't forget to copy the list... Thanks for looking into this. As an illustration, a reboot looks like this in the syslog: Mar 3 17:20:55 mach kernel: Kernel logging (proc) stopped. Mar 3 17:20:55 mach kernel: Kernel log daemon terminating. Mar 3 17:20:56 mach exiting on signal 15 Mar 3 17:27:00 mach syslogd 1.4.1#18: restart. Mar 3 17:27:00 mach kernel: klogd 1.4.1#18, log source = /proc/kmsg started. [boot messages should have been inserted here.] Mar 3 17:27:00 mach kernel: Enabled Mar 3 17:27:00 mach kernel: sdd:<6>sd 0:0:0:3: [sdd] Device not ready: <6>: Sense Key : Not Ready [current] Mar 3 17:27:00 mach kernel: : Add. Sense: Logical unit not ready, manual intervention required Mar 3 17:27:00 mach kernel: end_request: I/O error, dev sdd, sector 0 Mar 3 17:27:00 mach kernel: sd 0:0:0:3: [sdd] Device not ready: <6>: Sense Key : Not Ready [current] Mar 3 17:27:00 mach kernel: : Add. Sense: Logical unit not ready, manual intervention required Mar 3 17:27:00 mach kernel: end_request: I/O error, dev sdd, sector 0 [the above 3 lines 7 more times] Mar 3 17:27:00 mach kernel: Dev sdd: unable to read RDB block 0 [those 3 lines 2 more times] Mar 3 17:27:00 mach kernel: sd 0:0:0:3: [sdd] Device not ready: <6>: Sense Key : Not Ready [current] Mar 3 17:27:00 mach kernel: : Add. Sense: Logical unit not ready, manual intervention required Mar 3 17:27:00 mach kernel: end_request: I/O error, dev sdd, sector 24 Mar 3 17:27:00 mach kernel: printk: 29 messages suppressed. Mar 3 17:27:00 mach kernel: sd 0:0:0:3: [sdd] Device not ready: <6>: Sense Key : Not Ready [current] Mar 3 17:27:00 mach kernel: : Add. Sense: Logical unit not ready, manual intervention required Mar 3 17:27:00 mach kernel: end_request: I/O error, dev sdd, sector 24 Mar 3 17:27:00 mach kernel: sd 0:0:0:3: [sdd] Device not ready: <6>: Sense Key : Not Ready [current] Mar 3 17:27:00 mach kernel: : Add. Sense: Logical unit not ready, manual intervention required Mar 3 17:27:00 mach kernel: end_request: I/O error, dev sdd, sector 0 Mar 3 17:27:00 mach kernel: unable to read partition table Mar 3 17:27:00 mach kernel: sd 0:0:0:3: [sdd] Attached SCSI disk Mar 3 17:27:00 mach kernel: sd 0:0:1:0: [sde] 10485760 512-byte hardware sectors (5369 MB) Mar 3 17:27:00 mach kernel: sd 0:0:1:0: [sde] Write Protect is off Mar 3 17:27:00 mach kernel: sd 0:0:1:0: [sde] Cache data unavailable Mar 3 17:27:00 mach kernel: sd 0:0:1:0: [sde] 10485760 512-byte hardware sectors (5369 MB) Mar 3 17:27:00 mach kernel: sd 0:0:1:0: [sde] Write Protect is off Mar 3 17:27:00 mach kernel: sd 0:0:1:0: [sde] Cache data unavailable Mar 3 17:27:00 mach kernel: sde: unknown partition table Mar 3 17:27:00 mach kernel: sd 0:0:1:0: [sde] Attached SCSI disk Mar 3 17:27:00 mach kernel: sd 0:0:1:1: [sdf] 419430400 512-byte hardware sectors (214748 MB) Mar 3 17:27:00 mach kernel: sd 0:0:1:1: [sdf] Test WP failed, assume Write Enabled Mar 3 17:27:00 mach kernel: sd 0:0:1:1: [sdf] 419430400 512-byte hardware sectors (214748 MB) Mar 3 17:27:00 mach kernel: sd 0:0:1:1: [sdf] Test WP failed, assume Write Enabled Mar 3 17:27:00 mach kernel: sdf:<6>sd 0:0:1:1: [sdf] Device not ready: <6>: Sense Key : Not Ready [current] Mar 3 17:27:00 mach kernel: : Add. Sense: Logical unit not ready, manual intervention required Mar 3 17:27:00 mach kernel: end_request: I/O error, dev sdf, sector 0 Mar 3 17:27:00 mach kernel: sd 0:0:1:1: [sdf] Device not ready: <6>: Sense Key : Not Ready [current] Mar 3 17:27:00 mach kernel: : Add. Sense: Logical unit not ready, manual intervention required Mar 3 17:27:00 mach kernel: end_request: I/O error, dev sdf, sector 0 [and so on] It would be possible to grep out the offending lines, but I'd rather fight the cause than the symptom. Doing my research I realized I'm not alone with this problem. Looks like a recompilation is necessary, so I'm turning this into a feature request: how could selective partition check be added to the Linux kernel? I'm willing to give it a shot under some expert guidance. -- Thanks, Feri. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
