Local Storage¶
Local Sysdisk¶
After the PXE installation, the OS drive should be split into 5 partitions (with Ubuntu 18.04 LTS).
The last partition corresponds to the additional storage not used for OS, swap or var, and should be mounted on /local_sysdisk.
This is usually handled by the post-install script, under the function setup_local_automounts which updates the file /etc/fstab with the following line:
/dev/sda5 /local_sysdisk ext4 defaults 0 0
However, it can happend that the OS disk is given a different name than sda, in which case the system is left misconfigured and boot into emergency mode.
In that case, the file /etc/fstab needs to be updated manually with the correct disk name (check with lsblk for example).
RAID array¶
If the machine is used as a scratch space, it should be configured with either a Hardware of Software RAID array.
Software RAID¶
After PXE install, you can check if the software RAID is recognized with cat /proc/mdstat or mdadm --detail.
The softare RAID might be in auto-read-only mode by default after the first boot, in which case you need to run mdadm --readwrite /dev/mdX.
Once you have an operational software RAID device /dev/mdX, you need to mount it under /local_scratch.
To do so, add the following line to /etc/fstab if it is not there already:
/dev/mdX /local_scratch auto defaults 0 0
Then you can mount it with mount -a.
Hardware RAID¶
You can check that an Hardware RAID device is present with lspci | grep -i raid.
If so, check the name of the device with lshw -C disk (let’s say /dev/sdb), and add the following line to /etc/fstab:
/dev/sdb /local_scratch auto defaults 0 0
You can repeat this process if there are several HW RAID arrays and mount the second one under /local_scratch2.
Then you can mount it with mount -a.
Note
On clear, the file /etc/fstab is a bit different
/dev/sdb /local_scratch xfs inode64,nobarrier,noatime 0 0
Some optimization can be done in the choice of the filesystem and the mount options when creating a hardware RAID.