Hello,
I have Red Hat 5.7 running on HP hardware box. All file systems (except root) are in LVM. I have to create a new file-system and Storage team allocated 8 luns to this server. I scanned them on OS level with below command
for x in {0..9}; do echo '- - -' > /sys/class/scsi_host/host$x/scan; done
When I checked in inq, I can only see sd device, it means OS is able to see new devices. But dm devices are not created
[root@plsas_fin ~]# inq -nodots | egrep -i "0FBB|0FBC|0FBD|0FBE|0FBF|0FC0|0FC1|0FC2"
/dev/sdac :EMC :SYMMETRIX :5874 :0800fbb000 : 9144000
/dev/sdad :EMC :SYMMETRIX :5874 :0800fbc000 : 9144000
/dev/sdae :EMC :SYMMETRIX :5874 :0800fbd000 : 9144000
/dev/sdaf :EMC :SYMMETRIX :5874 :0800fbe000 : 9144000
/dev/sdag :EMC :SYMMETRIX :5874 :0800fbf000 : 9144000
/dev/sdah :EMC :SYMMETRIX :5874 :0800fc0000 : 9144000
/dev/sdai :EMC :SYMMETRIX :5874 :0800fc1000 : 9144000
/dev/sdaj :EMC :SYMMETRIX :5874 :0800fc2000 : 9144000
/dev/sdak :EMC :SYMMETRIX :5874 :0800fbb000 : 9144000
/dev/sdal :EMC :SYMMETRIX :5874 :0800fbc000 : 9144000
/dev/sdam :EMC :SYMMETRIX :5874 :0800fbd000 : 9144000
/dev/sdan :EMC :SYMMETRIX :5874 :0800fbe000 : 9144000
/dev/sdao :EMC :SYMMETRIX :5874 :0800fbf000 : 9144000
/dev/sdap :EMC :SYMMETRIX :5874 :0800fc0000 : 9144000
/dev/sdaq :EMC :SYMMETRIX :5874 :0800fc1000 : 9144000
/dev/sdar :EMC :SYMMETRIX :5874 :0800fc2000 : 9144000
When I scan devices, I see below errors in /var/adm/messages
Mar 18 22:35:40 plsas_fin kernel: ata1: hard resetting link
Mar 18 22:35:41 plsas_fin kernel: ata1: SATA link up 1.5 Gbps (SStatus 113 SControl 300)
Mar 18 22:35:41 plsas_fin kernel: ata1.00: configured for UDMA/100
Mar 18 22:35:41 plsas_fin kernel: ata1: EH complete
Mar 18 22:35:41 plsas_fin kernel: ata2: hard resetting link
Mar 18 22:35:41 plsas_fin kernel: ata2: SATA link down (SStatus 4 SControl 300)
Mar 18 22:35:41 plsas_fin kernel: ata2: EH complete
I can not see new devices in "multipath -ll". Did anybody faced this kind of issue or anybody can give some pointer ? It is production box, so reboot is not a option with me, unless that is last resort.
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Seems like somebody removed few devices improperly and that left some unusable entries in /dev. I had to run multipath -F and that flushes and fixed the issue.