Sanity check my setup...

[Matthew Kent]

I'm setting up a FreeNAS box that will eventually store BackupExec backups in a production environment. I've built my hardware and all seems to be working nicely.

I have 24TB of available disk space as a ZFS volume, which I want to split into an 18Tb and a 6Tb file extent to access through iSCSI.

Having read some other posts on the forum some users suggest creating the file extents manually using 'dd' so that the file extents won't be over-provisioned and run into problems if they fill up - does this sound sensible?

Also should I leave some 'whitespace' on the ZFS volume for FeeNAS to be happy, or can I just provision the whole lot?

Thanks,
Matt

 

[cyberjock]

I didn't make the file extent via dd, but I'm not having problems that I can identify.

As for the white space, pools shouldn't be filled to more than 80% or so.

 

[Matthew Kent]

Thanks, I'm having trouble creating the file extent (being a n00b). I tried
dd if=/mnt/Data of=backup_data bs= 20684562497536 count=1
but I get a filesystem is read-only error, any ideas?

 

[cyberjock]

Last I checked "Data" is not a pool name you should use as its reserved for other functions.

Also, you can't do a block size of that size(I got a BIG laugh on that one because I've never seen someone try to do that). What you will need to do is choose a bs of 1 megabyte(or at least something small) and then do a count of however many megabytes you want.

 

[Matthew Kent]

Great, thanks for the clarification, busy doing a dd from /dev/zero to my file extent. We'll see how long 20TB takes :)

 

[cyberjock]

My understanding of the dd command when you are doing writes is the block size determine the amount of RAM for stored data. So the block is filled in RAM, then flushed to disk. In your case, a system with 20TB of RAM would be necessary. That's why I got a good laugh.