MLM Server Virtual Machine Disk Volume Shrink?

[m_chethan]

Hi Everyone,

I am working on a use case where a customer has two MLM Log Servers deployed as virtual machines. The customer now wants to reduce the storage allocated to these servers, as they believe the current allocation is significantly over‑provisioned.

The storage has already been mapped and allocated to the existing log and current partitions, and both servers are currently in production.

My understanding is that it is not possible to shrink an existing logical volume/filesystem in this scenario once it has been allocated and is in use.

However, I would like to validate this with a broader audience:

• Is there a native and supported method to reduce the allocated storage on an existing server?
• Or is the only practical approach to rebuild the servers with the desired storage allocation and migrate the logs/database to the newly deployed servers?

I would appreciate any guidance or recommendations based on similar deployments or experiences.

sk95566 - Managing partition sizes through the LVM manager on Gaia OS

Regards,

Chethan

[Lesley]

The problem is that the host of the storage for example VMware is not aware what part of the storage is used and what is not used. That is why it can only add and not remove. Assuming customer used the recommend way: thickprovisioning. Most safe way is new machine and export and import. 

[Bob_Zimmerman · Accepted solution]

XFS (the filesystem used by all new Check Point installations since R80.30) can be expanded in-place, but cannot be contracted in-place. Once the storage has been allocated to lv_log or lv_current, you're done. The only option to shrink the system is rebuilding.

If the space you want to reclaim is in the pv but hasn't been allocated to an lv yet, you can use pvresize(8) to shrink the pv, then fdisk(8) to shrink the partition. Shrink the pv further than you plan to shrink the partition, then after the partition work, expand the pv to the full partition. That might allow the hypervisor to reclaim some physical storage it has provisioned for the VM. More often, though, this will also involve rebuilding.

[m_chethan]

Thank you! That makes total sense.