What factors should I consider before installing BIG-IQ software?

Before you install a BIG-IQ® system you should make sure of a couple things about the virtual disk on which your BIG-IQ system resides, so that all goes as planned when you install your software.

Questions to ask before you install

Determining the correct volume sizes for your new BIG-IQ installation

When you install BIG-IQ® VE, you need to know how big the volumes should be to handle the amount of data you intend to store. The volume size requirements can vary significantly, depending on how you use the BIG-IQ system.

If you are installing a BIG-IQ system, the volume sizes you need also depend on how you plan to manage your BIG-IP® devices and how many you plan to manage.

• The /var volume is used to store BIG-IQ local databases. In a typical system managing 600 BIG-IP devices, you can expect about 20 GB total disk space used. This size can vary greatly depending on the services discovered and type of objects being managed. Snapshots are stored in this volume, so if you schedule a lot of snapshots, your requirements will increase. For our scale testing, we found that 50GB was sufficient. If you schedule a large number of snapshots, that need could increase to 100GB.
• The /shared volume is used to store the backups; both for the BIG-IP devices you manage and the BIG-IQ itself. Larger amounts of disk space can be needed here, depending on how many devices you manage, how often they are backed up, and how many of these backups you opt to retain. You can specify how many backups you want to keep for each managed device. The storage auto-purges older backups if that number is exceeded. This feature can help prevent you from accidentally exhausting the available disk space. For our scale testing, we found that 300GB was sufficient for managing 600 BIG-IP devices. 100GB was sufficient for managing 200 BIG-IP devices or less. To err on the side of caution, 300GB is a good guideline.

If you are installing a DCD, the volume sizes you need depend on the number of BIG-IP devices you are collecting data for, as well as the number of DCDs in your cluster. Refer to the F5 BIG-IQ Centralized Management DCD Sizing Guide for additional detail.

Download disk size tools

F5 has created several scripts that are useful if you need to resize your disk volumes as part of the upgrade process. On a BIG-IQ® system or DCD with version 5.4.0 installed, these scripts are available in the /usr/bin folder. Because this folder is already in your path definition, you can use these scripts directly. To use these scripts with BIG-IQ systems or DCDs running versions prior to version 5.4.0, you must first download them.

1. Log in to downloads.f5.com.

2. Navigate to BIG-IQ Centralized Management, v5.4.0, and click I Accept to accept the EULA.

3. Click F5_Networks_Disk_Size_Tools.zip.

   After a brief pause, the Download Locations screen opens.

4. Click a download location to start the download.

5. When the download completes, unzip the file.

   Three files will extract to the folder you designate:

   • addvol
   • imageplan
   • resizevol

Before you can run these scripts, you need to copy them to the device you are resizing.

Create correctly sized volumes

Before you create correctly sized volumes you need to:

• Download the resizevol script from F5.downloads.com. For details on downloading this script, refer to Downloading disk size tools on support.f5.com.
• Know the volume names that you want to extend, and the size that you want to extend them to.

If you need to increase the volume size of a disk volume, you can use the resizevol script.

1. Use SSH to log in to your DCD as root.

2. Use the resizevol script to increase size of the volume on the new installation slot to the required size.

   The volume sizes required depend on a number of factors. See What volume sizes should I use? on support.f5.com for details.

   Here is an example of the resizevol script being used to resize the /var volume to 30 GB.

   Copy

   
   # `./resizevol /var 30000000`
   Requested size 30000000k is less than current size 30003200.00k on /dev/vg-db-sda/set.1._var, skipping
   Resizing logical volumes. OK (y/n)? y
   Requested size 30000000k is less than current size 30003200.00k, skipping
   e2fsck 1.41.12 (17-May-2010)
   Pass 1: Checking inodes, blocks, and sizes
   Pass 2: Checking directory structure
   Pass 3: Checking directory connectivity
   Pass 4: Checking reference counts
   Pass 5: Checking group summary information
   set.2./var: 11/655360 files (0.0% non-contiguous), 79696/2621440 blocks
     Rounding size to boundary between physical extents: 28.61 GiB
     Extending logical volume set.2._var to 28.61 GiB
     Logical volume set.2._var successfully resized
   resize2fs 1.41.12 (17-May-2010)
   Resizing the filesystem on /dev/vg-db-sda/set.2._var to 7500800 (4k) blocks.
   The filesystem on /dev/vg-db-sda/set.2._var is now 7500800 blocks long.
   # lvs --unit=k
     LV            VG        Attr      LSize        Pool Origin Data%  Move Log Cpy%Sync Convert
     dat.log.1     vg-db-sda -wi-ao---  7168000.00k
     dat.maint.1   vg-db-sda -wi-a----   307200.00k
     dat.share.1   vg-db-sda -wi-ao--- 10240000.00k
     dat.swapvol.1 vg-db-sda -wi-ao---  1048576.00k
     set.1._config vg-db-sda -wi-ao---   503808.00k
     set.1._usr    vg-db-sda -wi-ao---  3452928.00k
     set.1._var    vg-db-sda -wi-ao--- 30003200.00k
     set.1.root    vg-db-sda -wi-ao---   450560.00k
     set.2._config vg-db-sda -wi-a----  3321856.00k
     set.2._usr    vg-db-sda -wi-a----  3452928.00k
     set.2._var    vg-db-sda -wi-a---- 30003200.00k
     set.2.root    vg-db-sda -wi-a----   450560.00k        

   The script extends the size of the volume you identify (/var in this example) to the size you enter (30GB in this example).