Forum Discussion
For so long time, I almost forget to post the good answer that I eventually found from the OS layer!
1) /usr/include/asm-generic/errno-base.h:
#define EINTR 4 /* Interrupted system call */
#define EMFILE 24 /* Too many open files */
2) /usr/include/scsi/sg.h:
/* Use negative values to flag difference from original sg_header structure. */
#define SG_DXFER_NONE -1 /* e.g. a SCSI Test Unit Ready command */
#define SG_DXFER_TO_DEV -2 /* e.g. a SCSI WRITE command */
#define SG_DXFER_FROM_DEV -3 /* e.g. a SCSI READ command */
Well done finding that information.
20:07:59.674 [17491] <3> send_command: TLD(1) [17491] unable to read ack from tldcd, Interrupted system call (4), stat = -2
From the error, and your findings it suggets that the interuppted system call hapens when we try and send somrthing to the robot, as opposed to reading some response ... eg. scsi mode sense, if scsi move_medium
So, it is interesting, but not groundbreaking in terms of what is wrong.
Is the issue intermittant, or happeneing 100% of the time.
- liuyl6 years agoLevel 6
I think that there should indeed be many tldcd child processes for the same robot opened by the corresponding media servers' requests during the robot inaction period, which also meanwhile result in the sending command failures of those tldcd child processes !
- mph9996 years agoLevel 6
No, there should only be tldcd process for one media server, that is the robot control host. Other media servers should not be zoned/ have visability of the robot.
Any media server that has drives in a robot, even if controlled by a different machine will have tldd process
The robot control host only, should have tldcd process. If the RCH also has drives, it will also have a tldd process.
- liuyl6 years agoLevel 6
My meaning might be misunderstood!
Surely one tldcd process for one media server, but when many bptm requests come from remote media servers to the same robot during a shorter time interval, that would result in many corresponding tldcd child processes on the RCH!
Notes: refer to my another post "The working mechanism about tldd/tldcd".
And If this robot was also at inaction status for some reason in the meantime, thus the above problem with EINTR/EMFI LE/SG_DXFER_TO_DEV would take place!
Related Content
- 6 years ago
- 2 years ago