Extend or Increase root File System Size on Exadata

When Exadata database machine is installed by Oracle ACS the root file system size is set to 30GB. This space may not be sufficient for storing large files, logfiles, patches and so on and it can be filled very quickly. So you must consider increasing the root file system to avoid space issues. The root file system is built on volume group which makes it easy to resize the logical volume on which the root file system is mounted.

Root file system is created on two system partitions LVDbSys1 and LVDbSys2 and both system partitions must be size equally at the same time. Only one system partition is active at any time and other is inactive.

In this article, we will demonstrate how you can extend/increase the root file system size on Exadata Compute node. This activity can be done online without any downtime if the file system feature supports it.

Steps to extend/increase the root file system on Exadata Compute node

Step 1: Get the current root file system size and utilization. Here we can see that the root file system was expanded early to 60GB and currently it is 100% used.

[root@dm01db01 /]# df -h /
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VGExaDb-LVDbSys1
                       59G   57G     0 100% /

Step 2: Get the logical volumne details

[root@dm01db01 /]# lvs -o lv_name,lv_path,vg_name,lv_size
  LV                 Path                            VG      LSize
  LVDbOra1           /dev/VGExaDb/LVDbOra1           VGExaDb 200.00g
  LVDbSwap1          /dev/VGExaDb/LVDbSwap1          VGExaDb  24.00g
  LVDbSys1           /dev/VGExaDb/LVDbSys1           VGExaDb  60.00g
  LVDbSys2           /dev/VGExaDb/LVDbSys2           VGExaDb  60.00g
  LVDoNotRemoveOrUse /dev/VGExaDb/LVDoNotRemoveOrUse VGExaDb   1.00g

Step 3: Check to make sure that root file system can be resized online. Execute the following to determine it. If you get an output the file system can be resized online

[root@dm01db01 /]# tune2fs -l /dev/mapper/VGExaDb-LVDbSys1 | grep resize_inode
Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize

[root@dm01db01 /]# dcli -g ~/dbs_group -l root 'tune2fs -l /dev/mapper/VGExaDb-LVDbSys1 | grep resize_inode'
dm01db01: Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
dm01db02: Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
dm01db03: Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
dm01db04: Filesystem features:      has_journal ext_attr resize_inode dir_index filetype needs_recovery extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize

Step 4: Get the current active partition information. Here the current active partition is LVDbSys1

[root@dm01db01 ~]# imageinfo

Kernel version: 4.1.12-94.7.8.el6uek.x86_64 #2 SMP Thu Jan 11 20:41:01 PST 2018 x86_64
Image kernel version: 4.1.12-94.7.8.el6uek
Image version: 12.2.1.1.6.180125.1
Image activated: 2018-04-13 22:11:49 -0500
Image status: success
System partition on device: /dev/mapper/VGExaDb-LVDbSys1


Step 5: Get the free space available in the Volume Group. Currently we have around 1.3TB free space available. So we can easily increase the root file system.

[root@dm01db01 /]# vgdisplay -s
  "VGExaDb" 1.63 TiB  [345.00 GiB used / 1.30 TiB free]

Step 6: Using lvextend command increase the both logical volumes. In our case, we are increasing the root file system by 30GB to make 90GB total size.

[root@dm01db01 /]# lvextend -L +30G /dev/VGExaDb/LVDbSys1
  Size of logical volume VGExaDb/LVDbSys1 changed from 60.00 GiB (15360 extents) to 90.00 GiB (23040 extents).
  Logical volume LVDbSys1 successfully resized.

[root@dm01db01 /]# lvextend -L +30G /dev/VGExaDb/LVDbSys2
  Size of logical volume VGExaDb/LVDbSys2 changed from 60.00 GiB (15360 extents) to 90.00 GiB (23040 extents).
  Logical volume LVDbSys2 successfully resized.

Step 7: Using resize2fs command resize the file system as follows

[root@dm01db01 /]# resize2fs /dev/VGExaDb/LVDbSys1
resize2fs 1.43-WIP (20-Jun-2013)
Filesystem at /dev/VGExaDb/LVDbSys1 is mounted on /; on-line resizing required
old_desc_blocks = 4, new_desc_blocks = 6
The filesystem on /dev/VGExaDb/LVDbSys1 is now 23592960 blocks long.

[root@dm01db01 /]# e2fsck -f /dev/VGExaDb/LVDbSys1
e2fsck 1.43-WIP (20-Jun-2013)
/dev/VGExaDb/LVDbSys1 is mounted.
e2fsck: Cannot continue, aborting.


[root@dm01db01 /]# resize2fs /dev/VGExaDb/LVDbSys2
resize2fs 1.43-WIP (20-Jun-2013)
Please run 'e2fsck -f /dev/VGExaDb/LVDbSys2' first.

[root@dm01db01 /]# e2fsck -f /dev/VGExaDb/LVDbSys2
e2fsck 1.43-WIP (20-Jun-2013)
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
/dev/VGExaDb/LVDbSys2: 167407/3932160 files (0.1% non-contiguous), 4710754/15728640 blocks

[root@dm01db01 /]# resize2fs /dev/VGExaDb/LVDbSys2
resize2fs 1.43-WIP (20-Jun-2013)
Resizing the filesystem on /dev/VGExaDb/LVDbSys2 to 23592960 (4k) blocks.
The filesystem on /dev/VGExaDb/LVDbSys2 is now 23592960 blocks long.

Note: You can't run the e2fsck for the active paritition LVDbSys1. You run the e2fsck for inactive partition LVDbSys2 first before resizing it.

Step 8: Verify the new file system size

[root@dm01db01 /]# df -h /
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/VGExaDb-LVDbSys1
                       89G   57G   29G  67% /

Repeat the steps above on all the compute nodes in the Exadata Rack.


Conclusion

In this article we have learned how to extend/increase the root file system on Exadata Compute node online without any outage. Root file system is created on two system partitions LVDbSys1 and LVDbSys2 and both system partitions must be size equally at the same time. Only one system partition is active at any time and other is inactive.