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Disk-Based Recording

We now have two separate Xraid systems as Hobart, located in rack 6. They are labelled as A (lower Xraid) and B (upper Xraid) respectively. The arrays will be mounted now as /exports/xraid/Al_1, /exports/xraid/Ar_1, /exports/xraid/Bl_1 and /exports/xraid/Br_1. The right hand side of the B xraid is currently unusable for recording to. It may be ok for reading from with e-transfers but this hasn’t been tested. If you need to check on the health of the arrays, you can use the RAID Administration tool (as root on hovsi). This is described in more detail in the next section. The lower Xraid (A) is called Xserve-Xraid with IP 131.217.63.143 and the upper Xraid (B) is called HOXRAID2 with IP 131.217.63.144.

Changing Xraid disks

To change Xraid sets, you have to power down the entire Xraid. First, make sure that there are no recordings using disks on the Xraid to be shut down. With older version of recorder_server, it was necessary to stop it before unmounting drives. Happily, this is no longer required. Next, log into hovsi as root and check for any processes which are using the disks - you can check for these with
fuser -m /exports/xraid/Ar_1
This will report a list of process numbers which can be killed with kill −9 12345* where 12345 is the process number. Repeat for the other disk (fuser -m /exports/xraid/Al_1).

Once there are no processes using the disks, you can then use the command ./unmount_xraids_new.A.pl in the /root/ directory. Check that it has worked with
df -h
It should not show any mounted xraid drives on /exports/xraid/A*. Now you can turn off the Xraid unit itself by pressing and holding the glowing white power button that is located on the back of the unit. Hold it down until the green lights on the back start to flash, and then release. It takes a few seconds to shut down and once it is powered off (no lights on the front panel and the power light should be slowly pulsing), the drives can be removed by pressing the front panels and then sliding out the drives. If the Xraid does not shut down properly (so that it still shows green lights on the front or flashing lights do not stop) try waking it up up with one short pres of the power button, waiting 30 seconds or so and then trying again.

Pack the drives in their correct order in their aluminium case. Get a fresh set of disks and place them in the slots of the Xraid rack, in their correct order with 1 to the left and 7 on the right. If the disks are out of order, the Xraid system will be marked as faulty which can destroy data and take the set out of use for a day or more while the array is rebuilt. Make sure the disks are fully inserted also - the covers should be flush with the front of the array. Once the disks are loaded, the unit can be turned on by pressing the power button. Wait a minute or so while watching the LEDs on the front panel. There should be 4 green lights above each array and green lights lit on each drive when it is finally ready. To check that everything’s ok, load the RAID array manager on hovsi to check the disk. You can do this as root by
cd /root/RAID\ Admin\ 1.5.1/
and then
java -jar RAID_Admin.jar
. Select the Xraid by clicking on it and then check each of the arrays and individual disks by clicking on them (from the “Arrays and Drives” tab). The Raid Status should be “Online” and each drive should be labeled “Ok”. If everything is correct, exit the RAID managed and mount the xraids with the command
./mount_xraids_xfs.A.sh
in /root/ on hovsi. If you only want to mount one side, then use ./mount_xraids_xfs.Al.sh or ./mount_xraids_xfs.Ar.sh . As Br_1 is currently no good, you should only use ./mount_xraids_xfs.Bl.sh when mounting from the B bank.

This script will load the disk set on the left side of the A Xraid as \exports\xraid\Al_1 (and \exports\xraid\Al_2 if it is partitioned into two slices) and the one on the right as \exports\xraid\Ar_1. Test that they are correctly mounted by issuing these commands as vlbi
cd /exports/xraid/Ar_1/

vsib_record -t 30s
The recorded files can be deleted afterward.

All going well, cDisko should recognise the new drives as ready for use. This might take a minute or so while cDisko updates it info, and can display incorrect label assignments, etc, while it is settling.

Now, all that remains is to label the disks. Get the device id’s of the disksets using df -h The output should show something like
/dev/sde1 2.7T 100M 2.7T 0% /exports/xraid/r_1
which means that the right-hand disk disk set of the Xraids is device /dev/sde1, has 2.7 TB capacity and is mounted as /exports/xraid/r_1 . The disks need a file system label. Check if it is already set by typing (as root)
e2label /dev/sde1/
That should return the same string as the labels on the front of the disk. If it isn’t set, or is incorrect you can set the label (as root) by
e2label /dev/sde1/ “ATNF_V006A”.

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Page last modified on March 24, 2011, at 12:57 AM