hi Alan: >> > E.g. issue an sg_read for one sector to the device every 4m: >> > >> > */4 * * * * sg_read count=1 if=/dev/<disk> >> Since my target platform arm embedded system, >> does that mean I should include sg_read in my Busybox >> or >> cross-compile sg_read from sg3_utils? > > An alternative is to write a positive value, such as 240000, to > > /sys/block/sdX/events_poll_msecs > > where X is replaced with the proper drive letter. (240000 ms = 240 s = > 4 m.) I'm not sure this will work, but it's worth a try. I cannot find events_poll_msecs you mentioned in my system. Is this capability related to kernel version? ( my kernel version is 2.6.38.8 ) Sincerely appreciate all yours kind help, PS: below is result of /sys/block/sdb/ /sys/block/sdb# ls -lht total 0 -r--r--r-- 1 root root 4.0K 2014-07-08 00:08 alignment_offset lrwxrwxrwx 1 root root 0 2014-07-08 00:08 bdi -> ../../../../../../../../../../virtual/bdi/8:16 -r--r--r-- 1 root root 4.0K 2014-07-08 00:08 capability -r--r--r-- 1 root root 4.0K 2014-07-08 00:08 dev lrwxrwxrwx 1 root root 0 2014-07-08 00:08 device -> ../../../3:0:0:0 -r--r--r-- 1 root root 4.0K 2014-07-08 00:08 discard_alignment -r--r--r-- 1 root root 4.0K 2014-07-08 00:08 ext_range -r--r--r-- 1 root root 4.0K 2014-07-08 00:08 inflight drwxr-xr-x 2 root root 0 2014-07-08 00:08 power -r--r--r-- 1 root root 4.0K 2014-07-08 00:08 stat drwxr-xr-x 2 root root 0 2014-07-08 00:08 trace drwxr-xr-x 2 root root 0 2014-07-08 00:05 holders drwxr-xr-x 3 root root 0 2014-07-08 00:05 queue -r--r--r-- 1 root root 4.0K 2014-07-08 00:05 range -r--r--r-- 1 root root 4.0K 2014-07-08 00:05 ro drwxr-xr-x 5 root root 0 2014-07-08 00:05 sdb1 -r--r--r-- 1 root root 4.0K 2014-07-08 00:05 size drwxr-xr-x 2 root root 0 2014-07-08 00:05 slaves -r--r--r-- 1 root root 4.0K 2014-07-08 00:05 removable lrwxrwxrwx 1 root root 0 2014-07-08 00:05 subsystem -> ../../../../../../../../../../../class/block -rw-r--r-- 1 root root 4.0K 2014-07-08 00:05 uevent /sys/block/sdb# -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
