[mikepatt77]

I installed XBMC on Ubuntu on my old machine but I had a bit of an odd issue due to an external monitor and the resolution I had it set at. So I decided I should try again.

I originally had my external drive hooked up to the machine but this meant that the media center had to be pretty stationary. This is where FreeNAS comes in. I saw the below post on it and I thought what if I installed FreeNas on the old machine and hooked up my external drives to that and combine it with an XBMC on Ubuntu installed to a flash drive. This would mean I could carry around my media center and use it where ever there's a decent computer.

So after all that, my questions come down to: Is it possible for the XBMC application on Ubuntu to access the files through FreeNAS?

http://lifehacker.com/5822590/turn-an-ol...th-freenas

[TheSwissKnife]

I have been doing just that for a long time. FreeNAS/RAID-Z over 9 disks, the only issues I have had are 1) ZFS writes can starve the reads, so I have tuned done write performance to alleviate the affect that copying data onto it has when playing streams from it. 2) disk spin up from standby takes too long across that many disks as it is done in sequence so disks must be set not to power down.

[mikepatt77]

Thank you, TheSwissKnife. I'm a bit new to this though, so I'm a bit confused by number 1 in your post. From what I know, RAID-Z is a kind of a storage and ZFS is a file system. Why are you using those? How do you tune write performance? And do I need to do any of that?

[TheSwissKnife]

RAID-Z is one way to implement ZFS. ZFS a filesystem that makes it quite simple to deal with the physical storage to be presented as filesystems...importantly it offers a layer of data integrity not present in virtually any other filesystem so that data corruption caused by various possible methods can be detected and corrected. RAID-Z option is an option to give data redundancy so that simplistically put allows a single disk failure to not cause the loss of all data nor access. ZFS uses a data writing method that essentially makes all writes become essentially sequential in nature regardless of where the old copy of the data being written resided on the disks. The trouble with data structure used with RAID-Z is that the read performance becomes more or less like that of single disk, and additionally the writes like to be buffered up into very big ones...the combination of the two effects means that when copying data onto the filesystem data being read off can be relatively slow.

Will you have similar issues?...I don't know! When planning a NAS it helps to understand what you want to achieve first...ie what will you use it for, what performance level is required, do you care about losing the data if a disk fails, do you care about getting data corruption even if relatively unlikely and infrequent, will you need to add disks and grow the filesystem with ease in the future, can you have manage with separate filesystems, do you need to do backups and how often...

Not until you have some idea of these and other questions will you be able to choose your NAS solution properly. However most people don't and just pick one and get on with it...dealing with any frailties if they become an issue. All I can say is the FrreeNAS is a very good option if you want ZFS...the only reasonable alternatives being opensolaris based and these when I last looked lack such a friendly GUI and seemed less compatible with hardware (SATA support for each different type of controller was always a pain, or specific network interface support).