The strange behavior of some /dev/sg* files
RHEL 6.4
Why only some fixed /dev/sg* file would randomly change with shift or lose with - for some unknown reason sometimes？
Notes: but the corresponding /dev/st* files themselves do not change or lose！And such problem must be resolved via reboot！
Normal：
# # # lsscsi -g ...... [1:0:7:0] tape HP Ultrium 6-SCSI J3KZ /dev/st28 /dev/sg37 [1:0:7:1] mediumx ADIC Scalar i6000 680Q /dev/sch4 /dev/sg41 [1:0:8:0] tape HP Ultrium 6-SCSI J3KZ /dev/st29 /dev/sg39 [1:0:9:0] tape HP Ultrium 6-SCSI J3KZ /dev/st30 /dev/sg40 [1:0:10:0] tape HP Ultrium 6-SCSI J53Z /dev/st31 /dev/sg38 [1:0:11:0] tape HP Ultrium 6-SCSI J3KZ /dev/st32 /dev/sg42 [1:0:12:0] tape HP Ultrium 6-SCSI J3LZ /dev/st33 /dev/sg43 [1:0:13:0] tape HP Ultrium 6-SCSI J5KZ /dev/st34 /dev/sg44 [1:0:14:0] tape HP Ultrium 6-SCSI J3KZ /dev/st35 /dev/sg45 # #
Abnormal：
# # # # lsscsi -g ...... [1:0:7:0] tape HP Ultrium 6-SCSI J3KZ /dev/st28 /dev/sg37 [1:0:7:1] mediumx ADIC Scalar i6000 680Q /dev/sch4 /dev/sg41 [1:0:8:0] tape HP Ultrium 6-SCSI J3KZ /dev/st29 /dev/sg39 [1:0:9:0] tape HP Ultrium 6-SCSI J3KZ /dev/st30 /dev/sg40 [1:0:10:0] tape HP Ultrium 6-SCSI J53Z /dev/st31 - [1:0:11:0] tape HP Ultrium 6-SCSI J3KZ /dev/st32 /dev/sg42 [1:0:12:0] tape HP Ultrium 6-SCSI J3LZ /dev/st33 /dev/sg43 [1:0:13:0] tape HP Ultrium 6-SCSI J5KZ /dev/st34 /dev/sg44 [1:0:14:0] tape HP Ultrium 6-SCSI J3KZ /dev/st35 /dev/sg45 # # # lsscsi -g|grep -i 1:0:10:0 [1:0:10:0] tape HP Ultrium 6-SCSI J53Z /dev/st31 - # # # # ls -l /sys/class/scsi_host/host1/scan --w------- 1 root root 4096 Oct 24 15:56 /sys/class/scsi_host/host1/scan # # # # lsscsi -g|grep -i 1:0:10:0 [1:0:10:0] tape HP Ultrium 6-SCSI J53Z /dev/st31 - # # # # echo 1 > /sys/class/scsi_device/1:0:10:0/device/delete # # # # lsscsi -g|grep -i 1:0:10:0 # # # # lsscsi -g|grep -i 1:0:10:0 # # # # ls -l /dev/st31 ls: cannot access /dev/st31: No such file or directory # # # # echo "- - -" > /sys/class/scsi_host/host1/scan # # # # lsscsi -g|grep -E "1:0:7:1|1:0:10:0" [1:0:7:1] mediumx ADIC Scalar i6000 680Q /dev/sch4 - [1:0:10:0] tape HP Ultrium 6-SCSI J53Z /dev/st31 /dev/sg41 # # # # # echo 1 > /sys/class/scsi_device/1:0:7:1/device/delete # # # # lsscsi -g|grep 1:0:7:1 # # # # echo "- - -" > /sys/class/scsi_host/host1/scan # # # # lsscsi -g|grep 1:0:7:1 [1:0:7:1] mediumx ADIC Scalar i6000 680Q /dev/sch4 /dev/sg41 # # # # lsscsi -g|grep -E "1:0:7:1|1:0:10:0" [1:0:7:1] mediumx ADIC Scalar i6000 680Q /dev/sch4 /dev/sg41 [1:0:10:0] tape HP Ultrium 6-SCSI J53Z /dev/st31 - # # # # echo 1 > /sys/class/scsi_device/1:0:7:1/device/delete # # # # echo 1 > /sys/class/scsi_device/1:0:10:0/device/delete # # # # lsscsi -g|grep -E "1:0:7:1|1:0:10:0" # # # # echo "- - -" > /sys/class/scsi_host/host1/scan # # # # lsscsi -g|grep -E "1:0:7:1|1:0:10:0" [1:0:7:1] mediumx ADIC Scalar i6000 680Q /dev/sch4 /dev/sg41 [1:0:10:0] tape HP Ultrium 6-SCSI J53Z /dev/st31 - # # # # echo 1 > /sys/class/scsi_device/1:0:10:0/device/delete # # # # lsscsi -g|grep -E "1:0:7:1|1:0:10:0" [1:0:7:1] mediumx ADIC Scalar i6000 680Q /dev/sch4 /dev/sg41 # # # # echo 1 > /sys/class/scsi_device/1:0:7:1/device/delete # # # # echo "- - -" > /sys/class/scsi_host/host1/scan # # # # lsscsi -g|grep -E "1:0:7:1|1:0:10:0" [1:0:7:1] mediumx ADIC Scalar i6000 680Q /dev/sch4 /dev/sg41 [1:0:10:0] tape HP Ultrium 6-SCSI J53Z /dev/st31 - # # # # echo 1 > /sys/class/scsi_device/1:0:10:0/device/delete # # # # lsscsi -g|grep -E "1:0:7:1|1:0:10:0" [1:0:7:1] mediumx ADIC Scalar i6000 680Q /dev/sch4 /dev/sg41 # # # # echo "- - -" > /sys/class/scsi_host/host1/scan # # # # lsscsi -g|grep -E "1:0:7:1|1:0:10:0" [1:0:7:1] mediumx ADIC Scalar i6000 680Q /dev/sch4 - [1:0:10:0] tape HP Ultrium 6-SCSI J53Z /dev/st31 /dev/sg41 # # # # lsscsi -g|grep -E "1:0:7:1|1:0:10:0" [1:0:7:1] mediumx ADIC Scalar i6000 680Q /dev/sch4 - [1:0:10:0] tape HP Ultrium 6-SCSI J53Z /dev/st31 /dev/sg41 # # #
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