I have a Blade Center H and a DS4700 SAN. Today we detected one problem in the mail service in one of the blades. It can't see a particular volume available in the SAN. All other blades can see SAN disks from
sdj , but this one sees only
sdi. The volume that is
sdd in all other blades is lost in this one and replaced by the next one.
I can mount
sdd1 in every other blade, so
sdd1 is working and has content. All servers are running CentOS 5.8. I'm totally lost here.
What thing can hide a disk from that system?
Edit: More info:
The HBAs are Emulex:
> lspci | grep -i emulex 03:05.0 Fibre Channel: Emulex Corporation Helios-X LightPulse Fibre Channel Host Adapter (rev 01) 03:05.1 Fibre Channel: Emulex Corporation Helios-X LightPulse Fibre Channel Host Adapter (rev 01)
The switch is an IBM TotalStorage SAN 16B-2. It was configured by the IBM personnel and it hasn't been touched by me.
The multipath is managed by the Linux RDAC multipath drivers for IBM SystemStorage provided by IBM personnel during the original installation.
> lsmod|egrep 'mpp|lpfc' mppVhba 165888 11 lpfc 515109 18 scsi_transport_fc 83145 1 lpfc mppUpper 165532 1 mppVhba scsi_mod 199001 18 be2iscsi,ib_iser,iscsi_tcp,bnx2i,cxgb3i,libiscsi2,scsi_transport_iscsi2,scsi_dh,mppVhba,usb_storage,lpfc,scsi_transport_fc,mptsas,mptscsih,scsi_transport_sas,mppUpper,sg,sd_mod
This is /proc/scsi
> ls /proc/scsi/ device_info mpp/ mptsas/ scsi sg/ > ls /proc/scsi/mpp/ 3
In some machines there is a /proc/scsi/lpfc folder too.