# Question on adding additional capacity



## dpalme (Apr 7, 2014)

I'm curious about something, I still have two caddies in the dell 2950 I'm using to add additional space.  I have a spare 1.5TB drive I'd like to put to use right now.  If I add that drive and the run GROWFS to expand the file system and then later decide I want to replace the drive with say a 2tb drive will that present a problem? 

I"m running a full raid 5 so I'm not as concerned with the drive replacement but being able to pick up the additional .5tb later on?


----------



## SirDice (Apr 7, 2014)

dpalme said:
			
		

> I'm curious about something, I still have two caddies in the dell 2950 I'm using to add additional space.  I have a spare 1.5TB drive I'd like to put to use right now.  If I add that drive and the run GROWFS to expand the file system and then later decide I want to replace the drive with say a 2tb drive will that present a problem?


As far as I know you can only use growfs(8) to expand an existing partition, you cannot use it to _add_ another disk. 



> I"m running a full raid 5 so I'm not as concerned with the drive replacement but being able to pick up the additional .5tb later on?


I've done that recently with a ZFS RAID-Z pool and it worked like a charm. Swapped out each 2 TB drive for a 3 TB one, let it resilver, then replaced the next one. Once all the drives were replaced the additional space became available.


----------



## dpalme (Apr 7, 2014)

So you're saying that there is no way to increase disk capacity with FreeBSD? 

That makes no sense.


----------



## wblock@ (Apr 7, 2014)

dpalme said:
			
		

> So you're saying that there is no way to increase disk capacity with FreeBSD?



No, that is not what he said.  growfs(8) is for enlarging UFS filesystems.  If your RAID has available space, that might work.  But a normal RAID5 will not give more space by replacing only one drive.


----------



## SirDice (Apr 8, 2014)

wblock@ said:
			
		

> But a normal RAID5 will not give more space by replacing only one drive.


Or by adding one drive.


----------



## Jimmy (Apr 8, 2014)

ZFS could really do with raid4 support for this scenario and the ability to rebuild the stripes+parity.


----------



## SirDice (Apr 8, 2014)

Jimmy said:
			
		

> ZFS could really do with raid4 support for this scenario and the ability to rebuild the stripes+parity.


It's not as easy as you might think. 

https://blogs.oracle.com/ahl/entry/expa ... tic_raid_z


----------

