disksetup
Describes the disksetup
command that formats disks for use by HPE Ezmeral Data Fabric
storage.
Description
disksetup
command must be run as root
.
disksetup
command formats specified disks for use by HPE Ezmeral Data Fabric storage, and adds those disks to the disktab file. You do not need to set up Redundant Array of Independent Disks (RAID) on disks used by
the file system. HPE Ezmeral Data Fabric uses disksetup
to set up storage pools. In most cases, you should let HPE Ezmeral Data Fabric calculate
storage pools using the default stripe width of two or three
disks. If you anticipate a high volume of random-access I/O, you can use the
-W
option to specify larger storage pools of up to 8 disks each.
See Setting Up Disks for Data Fabric for more information about when and how
to use disksetup
.
/usr/bin/python
to /usr/bin/python3
. The disksetup
command fails if /usr/bin/python
is not found.
sudo alternatives --set python /usr/bin/python3
Syntax
/opt/mapr/server/disksetup
[-F]
[-G]
[-X]
[-M]
[-W <stripe_width>]
<disk list file>
Options
Option |
Description |
---|---|
|
Forces formatting of all specified disks. Disks that are already
formatted for HPE Ezmeral Data Fabric are not
reformatted by |
|
Generates the |
-X |
Fixes disktab contents from
/proc/partitions , but does not format disks. Use this
option if there is a change in the names of the disk devices referenced by
disktab , but the disks themselves are still usable. For example, if /dev/sdb
has been renamed to /dev/sdf but the device itself has the same GUID, only
the disktab contents need to be updated to point to /dev/sdf . |
|
Uses the maximum available number of disks per storage pool. |
|
Specifies the number of disks per storage pool. |
Examples
Setting up disks specified in the file /tmp/disks.txt:/opt/mapr/server/disksetup -F /tmp/disks.txt
Reformatting
all disksTo reformat all disks, remove the disktab
file and
issue the disksetup -F
command to format the
disk:
/opt/mapr/server/disksetup -F
To reformat a particular
disk from the disktab
, use the maprcli disk remove
and maprcli disk add
commands. For more information, see Setting Up Disks for HPE Ezmeral Data Fabric.
To specify the disks to be formatted for use by the HPE Ezmeral Data Fabric cluster, create a text file /tmp/disks.txt
listing the disks and partitions for use by HPE Ezmeral Data Fabric on the node. Each line lists
either a single disk, or all applicable partitions on a single disk. When listing
multiple partitions on a line, separate each partition by spaces. For
example:
/dev/sdb
/dev/sdc1 /dev/sdc2 /dev/sdc4
/dev/sdd
Later,
when you run disksetup
to format the disks, specify the
disks.txt
file. For
example:
/opt/mapr/server/disksetup -F /tmp/disks.txt
The disksetup
command removes all data from the specified disks.
Ensure that you specify the disks correctly, and that you have backed up any data
that you wish to keep.
If you are re-using a node that was used previously in another cluster, be sure to format the disks to remove any traces of data from the old cluster.
Test Purposes Only: Using a Flat File for StorageWhen
setting up a small cluster for evaluation purposes, if a particular node does not have
physical disks or partitions available to dedicate to the cluster, you can use a flat
file on an existing disk partition as the node's storage. Create at least a 16GB file,
and include a path to the file in the disk list file for the
disksetup
script.
The following example creates a 20 GB flat file
(bs=1G
specifies 1 gigabyte blocks, multiplied by
count=20
) at
/root/storagefile
:
dd if=/dev/zero of=/root/storagefile bs=1G count=20
Next,
add the following entry to the disk list file /tmp/disks.txt
to be used
by disksetup
:
/root/storagefile