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'''<big>Setup an SME Server with 2 SSD’s in a RAID1 setup with Over Provisioning</big>'''

'''<big>Setup an SME Server with 2 SSD’s in a RAID1 setup with Over Provisioning</big>'''

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'''Write Amplification'''

'''Write Amplification'''

This manual describes how to setup an SME Server with 2 Solid State Drives (SSD’s) in a RAID1 setup with Over Provisioning to prevent Write Amplification.

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Also SSD’s in RAID5 is discouraged as it also vastly increases Write Amplification.

Because this is a manual on how to setup an SME Server with 2 SSD’s in a RAID1 setup with Over Provisioning to prevent Write Amplification, and not on What Write Amplification is exactly, I will not go into that any further.

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For more information on that, this is a good place to start:

For more information on that, this is a good place to start: http://en.wikipedia.org/wiki/Write_amplification

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http://en.wikipedia.org/wiki/Write_amplification

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'''Over Provisioning'''

'''Over Provisioning'''

Over Provisioning is a fancy term for partitioning xx% less than the full capacity of the disk.

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'''Setup an SME Server with 2 SSD’s in a RAID1 setup with Over Provisioning'''

'''Setup an SME Server with 2 SSD’s in a RAID1 setup with Over Provisioning'''

In the Boot Menu select Advanced installation options.

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In this example we choose English.

[[File:pic04.gif|589px|frameless|none|Picture 4]]

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Click next.

Click next.

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Select your keyboard layout.

Select your keyboard layout.

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In this example we choose U.S. English.

In this example we choose U.S. English.

[[File:pic05.gif|587px|frameless|none|Picture 5]]

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Click next.

Click next.

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Select Basic Storage Devices.

Select Basic Storage Devices.

[[File:pic06.gif|588px|frameless|none|Picture 6]]

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Click next.

Click next.

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Select Yes, discard any data.

Select Yes, discard any data.

[[File:pic07.gif|590px|frameless|none|Picture 7]]

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Click next.

Click next.

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Select your timezone.

Select your timezone.

[[File:pic08.gif|589px|frameless|none|Picture 8]]

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Click next.

Click next.

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Select Create Custom Layout.

Select Create Custom Layout.

[[File:pic09.gif|589px|frameless|none|Picture 9]]

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Click next.

Click next.

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You are given a default RAID1 layout which uses the full disk capacity.

You are given a default RAID1 layout which uses the full disk capacity.

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This is where we start costomizing the partition layout.

This is where we start costomizing the partition layout.

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For the example I have two 40GByte SSD disks.

For the example I have two 40GByte SSD disks.

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Both disks have a 250MB system partition (sda1 and sdb1) and a larger partition for the rest of the data (sda2 and sdb2).

Both disks have a 250MB system partition (sda1 and sdb1) and a larger partition for the rest of the data (sda2 and sdb2).

[[File:pic10.gif|590px|frameless|none|Picture 10]]

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Click next.

Click next.

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Remove all partitions by selecting sda and sdb and selection delete with both.

Remove all partitions by selecting sda and sdb and selection delete with both.

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After that you have a 2 partition free SSD’s like shown below.

After that you have a 2 partition free SSD’s like shown below.

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You can see the disk is 40959 MB in size.

You can see the disk is 40959 MB in size.

[[File:pic11.gif|590px|frameless|none|Picture 11]]

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Now, Over Provisioning usually is set somewhere between 5% and 25% and like said before, there is no right value to set for Over Provisioning.

Now, Over Provisioning usually is set somewhere between 5% and 25% and like said before, there is no right value to set for Over Provisioning.

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Usually people set it at 10% and that is what most SSD tools advise. Setting it lower than that will age your SSD disk faster and will compromise your SSD’s performance.

Usually people set it at 10% and that is what most SSD tools advise. Setting it lower than that will age your SSD disk faster and will compromise your SSD’s performance.

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If you are rather safe that sorry and the diskcapacity of your RAID1 set is not an issue you could set it to 15% or 20%.

If you are rather safe that sorry and the diskcapacity of your RAID1 set is not an issue you could set it to 15% or 20%.

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Setting it higher seems like overkill to me.

Setting it higher seems like overkill to me.

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In our example we will use 10% Over Provisioning.

In our example we will use 10% Over Provisioning.

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The system (250MB) and swap (4064MB) partitions will be the same size as in the default setting.

The system (250MB) and swap (4064MB) partitions will be the same size as in the default setting.

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That will make the size of the larger data partition: 40959MB x 0,9 = 36863MB – 250MB = 36613MB.

That will make the size of the larger data partition: 40959MB x 0,9 = 36863MB – 250MB = 36613MB.

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We will start bij partitioning disk sda.

We will start bij partitioning disk sda.

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Select sda and click create.

Select sda and click create.

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Select RAID Partition and click create.

Select RAID Partition and click create.

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Set all options like shown in the folowing screen and select OK:

Set all options like shown in the folowing screen and select OK:

[[File:pic12.gif|293px|frameless|none|Picture 12]]

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The size of the partition (250MB) will be the same whatever size SSD you will be using.

The size of the partition (250MB) will be the same whatever size SSD you will be using.

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Under sda select the Free space and click create.

Under sda select the Free space and click create.

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Select RAID Partition and click create.

Select RAID Partition and click create.

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Set all options like shown in the folowing screen and select OK:

Set all options like shown in the folowing screen and select OK:

[[File:pic13.gif|295px|frameless|none|Picture 13]]

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The size of the partition will be 90% of the SSD size - 250MB.

The size of the partition will be 90% of the SSD size - 250MB.

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So this size will depend on the size SSD you are using and using 10% Over Provisioning.

So this size will depend on the size SSD you are using and using 10% Over Provisioning.

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Now we will do the same for the disk sdb.

Now we will do the same for the disk sdb.

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Select sdb and click create.

Select sdb and click create.

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Select RAID Partition and click create.

Select RAID Partition and click create.

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Set all options like shown in the folowing screen and select OK:

Set all options like shown in the folowing screen and select OK:

[[File:pic14.gif|295px|frameless|none|Picture 14]]

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The size of the partition (250MB) will be the same whatever size SSD you will be using.

The size of the partition (250MB) will be the same whatever size SSD you will be using.

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Under sda select the Free space and click create.

Under sda select the Free space and click create.

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Select RAID Partition and click create.

Select RAID Partition and click create.

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Set all options like shown in the folowing screen and select OK:

Set all options like shown in the folowing screen and select OK:

[[File:pic15.gif|294px|frameless|none|Picture 15]]

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The size of the partition will be 90% of the SSD size - 250MB.

The size of the partition will be 90% of the SSD size - 250MB.

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So this size will depend on the size SSD you are using and using 10% Over Provisioning.

So this size will depend on the size SSD you are using and using 10% Over Provisioning.

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Select Hard Drives and select create.

Select Hard Drives and select create.

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Select RAID Device and click create.

Select RAID Device and click create.

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Set all options like shown in the folowing screen and select OK:

Set all options like shown in the folowing screen and select OK:

[[File:pic16.gif|239px|frameless|none|Picture 16]]

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Make sure you select both system partitions sda1 and sdb1 witch both are 250MB.

Make sure you select both system partitions sda1 and sdb1 witch both are 250MB.

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Select Hard Drives and select create.

Select Hard Drives and select create.

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Select RAID Device and click create.

Select RAID Device and click create.

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Set all options like shown in the folowing screen and select OK:

Set all options like shown in the folowing screen and select OK:

[[File:pic17.gif|240px|frameless|none|Picture 17]]

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Make sure you select both system partitions sda2 and sdb2.

Make sure you select both system partitions sda2 and sdb2.

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Under RAID Devices select md1 and click create.

Under RAID Devices select md1 and click create.

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Select LVM Volume Group and click create.

Select LVM Volume Group and click create.

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Select Add and set all options like shown in the folowing screen and select OK:

Select Add and set all options like shown in the folowing screen and select OK:

[[File:pic18.gif|323px|frameless|none|Picture 18]]

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Set the swap size the same as the default setting that was presented to you earlier.

Set the swap size the same as the default setting that was presented to you earlier.

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Select Add again and set all options like shown in the folowing screen and select OK:

Select Add again and set all options like shown in the folowing screen and select OK:

[[File:pic19.gif|323px|frameless|none|Picture 19]]

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Set the size the same as the maximum size shown in the same window.

Set the size the same as the maximum size shown in the same window.

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Select OK again in this window to start the installation.

Select OK again in this window to start the installation.

[[File:pic20.gif|323px|frameless|none|Picture 20]]

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The RAID1 set you just created is shown now.

The RAID1 set you just created is shown now.

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Notice that both sda and sdb have 10% of free space now.

Notice that both sda and sdb have 10% of free space now.

[[File:pic21.gif|592px|frameless|none|Picture 21]]

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Click next.

Click next.

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Select Write changes to disk.

Select Write changes to disk.

[[File:pic22.gif|235px|frameless|none|Picture 22]]

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After the partitioning/formatting has finished you will see the screen below:

After the partitioning/formatting has finished you will see the screen below:

[[File:pic23.gif|593px|frameless|none|Picture 23]]

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Click next.

Click next.

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The packages will now be installed.

The packages will now be installed.

[[File:pic24.gif|594px|frameless|none|Picture 24]]

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After some time your installation will be completed and you are asked to reboot:

After some time your installation will be completed and you are asked to reboot:

[[File:pic25.gif|592px|frameless|none|Picture 25]]

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Click Reboot.

Click Reboot.

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After reboot, finish your SME configuration as you are used to, set an admin password, IP-settings and so on…

After reboot, finish your SME configuration as you are used to, set an admin password, IP-settings and so on…

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Login to your server with user root and use the command cat /proc/mdstat to check if your RAID1 set is synchronising:

[[File:pic26.gif|591px|frameless|none|Picture 26]]

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After the synchronisation finished the command cat /proc/mdstat output should look something like this:

After the synchronisation finished the command cat /proc/mdstat output should look something like this:

[[File:pic27.gif|340px|frameless|none|Picture 27]]

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'''Tip:'''

'''Tip:'''

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Do not use the admin account to add an SSD disk to a RAID1 set that is custum partitioned to use less than 100% of the disk space from the menu (Option 5. Manage disk redundancy) because the script behind this option will not check how the disk that needs to be cloned is partitioned.

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The script will add the disk but will partition it using 100% of the disk space even when the first SSD disk in the RAID1 set is partitioned using less than 100% of the disk space.

The script will add the disk but will partition it using 100% of the disk space even when the first SSD disk in the RAID1 set is partitioned using less than 100% of the disk space.

Mike

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Retrieved from "https://wiki.koozali.org/Special:MobileDiff/25166"

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User:Mike (view source)

Revision as of 00:00, 17 September 2014

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