Installation guide

Scanning Storage Interconnects
131
local fcoe_disks=($(egrep 'by-path\/fc-.*_netdev' /etc/fstab | cut -d ' ' -f1))
test -z $fcoe_disks && return 0
echo -n "Waiting for fcoe disks . "
while [ $timeout -gt 0 ]; do
for disk in ${fcoe_disks[*]}; do
if ! test -b $disk; then
done=0
break
fi
done
test $done -eq 1 && break;
sleep 1
echo -n ". "
done=1
let timeout--
done
if test $timeout -eq 0; then
echo "timeout!"
else
echo "done!"
fi
# mount any newly discovered disk
mount -a 2>/dev/null
}
The mount_fcoe_disks_from_fstab function should be invoked after the fcoe service script
starts the fcoemon daemon. This will mount FCoE disks specified by the following paths in /etc/
fstab:
/dev/disk/by-path/fc-0xXX:0xXX /mnt/fcoe-disk1 ext3 defaults,_netdev 0 0
/dev/disk/by-path/fc-0xYY:0xYY /mnt/fcoe-disk2 ext3 defaults,_netdev 0 0
Entries with fc- and _netdev sub-strings enable the mount_fcoe_disks_from_fstab function
to identify FCoE disk mount entries. For more information on /etc/fstab entries, refer to man 5
fstab.
Note
The fcoe service does not implement a timeout for FCoE disk discovery. As such, the FCoE
mounting code should implement its own timeout period.
21.9. Scanning Storage Interconnects
There are several commands available that allow you to reset and/or scan one or more interconnects,
potentially adding and removing multiple devices in one operation. This type of scan can be disruptive,
as it can cause delays while I/O operations timeout, and remove devices unexpectedly. As such,
Red Hat recommends that this type of scan be used only when necessary. In addition, the following
restrictions must be observed when scanning storage interconnects:
1. All I/O on the effected interconnects must be paused and flushed before executing the procedure,
and the results of the scan checked before I/O is resumed.
2. As with removing a device, interconnect scanning is not recommended when the system is under
memory pressure. To determine the level of memory pressure, run the command vmstat 1 100;