Extend Storage

[Zainudin]

Hello All,


I have a DELL R540 server with RAID5 configuration with 6 disks and I installed the FreeNas OS for our office data storage, currently the hard drive has reached 80% capacity of existing capacity. I want to add a hard drive to the server. My question is when I add a hard drive from the Hardware RAID controller side, can it be read directly by the system or can it cause data to be lost?

 

[sretalla]

You should probably post your full system details as per the Red Forum Rules at the top of the page here...

Jumping to a conclusion based on what you have already said...

It seems you're using a RAID card to make a RAID5 volume and presenting that as a single disk to FreeNAS.

You have completely misunderstood how ZFS works and the correct way to use FreeNAS.

Please read this post:

What's all the noise about HBA's, and why can't I use a RAID controller?

This is relevant to FreeNAS and TrueNAS CORE. Some parts of it might also be relevant to Scale, but I don't really know how reliable the Linux drivers are. 1) An HBA is a Host Bus Adapter. This is a controller that allows SAS and SATA devices to be attached to, and communicate directly with...

www.truenas.com

You should prepare to:
1. Replace the RAID controller with an HBA card.
2. Backup, rebuild and restore the contents of your pool (after correctly building it with disks directly attached to the HBA and presented as individual disks for FreeNAS to perform the RAID functions with).

or

3. Stop using FreeNAS to store any data you don't want to lose.

 

[Arwen]

@Zainudin As @sretalla said, if you are using hardware RAID-5, that can be a problem.

You can, (and many people have), loose your data since hardware RAID cards re-order their writes, cache data, and will acknowledge writes before the data is on stable media. This is partly because ZFS will copy on write metadata, which if it becomes corrupt, it's possible that corruption is un-repairable, (beyond loosing what data that metadata pointed to).

If you are using hardware RAID-5, do not add a new disk to the RAID-5 set. Their is a chance to loose all your data. In essence, you are in rarely traveled area.

 

[RegularJoe]

you can add the disk to the PERC RAID set and use OCE to increase the size of the LUN, after that you have to reboot your FreeNAS box or poke the system to get it to re-read the new disk geomety. Then you have to tell ZFS to use the extra block space. I so something similar to this when I run FreeNAS as a VM on VMwarew and take the virtual disk from 100gb to 200gb...

What you really want is to read the docs and use a HBA, but since your down this road all you can do is use the Dell Perc OCE.