FreeNAS

[The_Unnamed]

Decided to make a quick post in the dark side of the linux forums that i hardly ever visit.
Getting my folks a WDTV Live media player and need some suggestions.

I was going to run FreeNAS on an old PC but i need to know if i will be able to run SABNZBD and Couchpotato with it also?
I did find a thing of 2 after a google search but i was wondering if anyone here had success with that combination?

[bin3]

In my view, Linux + LVM >> FreeNAS, but that's just my view.

[Have run FreeNAS for about 2 years, since moved over to OpenSUSE with Samba & LVM.

[Gnome]

The best way to sum it up is:

Linux offers RAID (classical RAID)
FreeNAS (FreeBSD not Linux) offers ZFS (Oracle/Sun Microsystem's solution for enterprise storage)

ZFS > RAID 5/6 in every which way, performance, data integrity, recovery, creation. The list continues, RAID 5/6 is just a mess.
ZFS Mirror > RAID 1 when it comes to data integrity, but RAID 1 has a slight performance advantage of ZFS Mirror.

ZFS is becoming increasingly popular in the enterprise space. The link above is a article by Anandtech where they compare a ZFS NAS to an enterprise hardware RAID system (in the R100K price tag range).

Then comes the second part.

Setup of Linux = Mission + hours of Googling, everything is tedious.
Setup of FreeNAS = Web-interface, everything is point & click, takes minutes if you use the tutorial as a guide.

To setup S.M.A.R.T monitoring of all your drives with error reports VIA email on Linux is a lot of work. On FreeNAS you click a few options.
To setup emailing if your software RAID is having problems in FreeNAS means filling out the email information, once again in Linux a mission.

The last part is sabNZBd. FreeNAS 8.2 is slated for release THIS month. The mayor change in FreeNAS 8.2 is plugin support.

Currently the 3 plug-ins available on the beta is sabNZBd, SickBeard & CouchPotato So you can bet that once the release is made end this month, it should have sabNZBd.

Lastly, running FreeNAS on an old PC:
You need a lot of RAM for FreeNAS (4GB minimum, 8GB recommended). CPU usage is not that critical but older PCs do tend to use a lot of power, so you might benefit by getting something like a HP Proliant Microserver which is low power.

If you have less than 4GB RAM, then give it a skip and go for Linux. FreeNAS won't even boot without 2GB and it'll be unstable with less than 4GB.

[The_Unnamed]

The best way to sum it up is:

Linux offers RAID (classical RAID)
FreeNAS (FreeBSD not Linux) offers ZFS (Oracle/Sun Microsystem's solution for enterprise storage)

ZFS > RAID 5/6 in every which way, performance, data integrity, recovery, creation. The list continues, RAID 5/6 is just a mess.
ZFS Mirror > RAID 1 when it comes to data integrity, but RAID 1 has a slight performance advantage of ZFS Mirror.

ZFS is becoming increasingly popular in the enterprise space. The link above is a article by Anandtech where they compare a ZFS NAS to an enterprise hardware RAID system (in the R100K price tag range).

Then comes the second part.

Setup of Linux = Mission + hours of Googling, everything is tedious.
Setup of FreeNAS = Web-interface, everything is point & click, takes minutes if you use the tutorial as a guide.

To setup S.M.A.R.T monitoring of all your drives with error reports VIA email on Linux is a lot of work. On FreeNAS you click a few options.
To setup emailing if your software RAID is having problems in FreeNAS means filling out the email information, once again in Linux a mission.

The last part is sabNZBd. FreeNAS 8.2 is slated for release THIS month. The mayor change in FreeNAS 8.2 is plugin support.

Currently the 3 plug-ins available on the beta is sabNZBd, SickBeard & CouchPotato So you can bet that once the release is made end this month, it should have sabNZBd.

Lastly, running FreeNAS on an old PC:
You need a lot of RAM for FreeNAS (4GB minimum, 8GB recommended). CPU usage is not that critical but older PCs do tend to use a lot of power, so you might benefit by getting something like a HP Proliant Microserver which is low power.

If you have less than 4GB RAM, then give it a skip and go for Linux. FreeNAS won't even boot without 2GB and it'll be unstable with less than 4GB.

Fantastic! Great post, thank you.
The PC is currently rocking 4gb of ram. I will pick up another 4 this weekend and wait for the FreeNAS 8.2 release.

[wezhira]

i think 4gb ram is alot hey i have fairly old pc athlon 2gb ram 2tb hdd run opensuse 11.4 transmission for torrents mediatomb for upnp /dlna , nfs ,samba i am happy

[Gnome]

i think 4gb ram is alot hey i have fairly old pc athlon 2gb ram 2tb hdd run opensuse 11.4 transmission for torrents mediatomb for upnp /dlna , nfs ,samba i am happy

Nothing is free, the cost of ZFS is, it loves memory (although at R200 for 4GB of RAM I don't think much of the cost). CPU power can also become a factor if you have seriously fast disks (SSDs) in large arrays (eg. 16 disks).

You sacrifice memory for the fact that you want a highly available, reliable and high speed file system. The file system wasn't made with cheap asses in mind

My NAS is running 16GB of RAM and most of the data is cached into the main memory when I start reading a file. The result is that I can actually read a file over multiple gigabit Ethernet interfaces (for testing I put 2 extra Intel Pro/1000 Network Adapters).

Had no problem copying the file to 3 different PCs at ~105MBytes/s for all 3. Writes are also cached to memory, so if I copy a file that is less than 16GB it is transferred to the cache until the disks become available (generally the 2TB disks I have are fast enough that a single copy operation need not be cached but multiple copy/read operations at the same time can cause the cache to get hit).

In a large company (eg. Data centre/ISP) the cost of buying a single NAS with 128GB RAM (for huge memory cache) that can saturate multiple 10 Gigabit Ethernet links is actually very low VS. multiple SANs.

[DrJohnZoidberg]

I wish btrfs would get a move on. Don't want to use it yet until its been through its paces, but looks very promising. Running software RAID5 with ext4 is too damn stressful.

Found a nice little article: http://www.phoronix.com/scan.php?pag...tem&px=MTA4Mzc

[Gnome]

brtfs IMHO is based on ZFS, the feature list for the final version of brtfs (whenever it will be released) will be the same as ZFS.

ZFS is just about 5 years ahead of brtfs. Only downside (of ZFS) is it isn't available on Linux because of Licensing issues (CDDL license of ZFS is not compatible with GNU licensing required for Linux kernel modules).

The irony is both ZFS and BRTFS is owned by Oracle. ZFS was originally developed by Sun Microsystems that was recently acquired by Oracle.

EDIT: Seems Wikipedia agrees:

In 2009, Btrfs was expected to offer a feature set comparable to ZFS, developed by Sun Microsystems.[8] After Oracle's acquisition of Sun in 2009, Mason still planned to develop Btrfs.

[ghoti]

The best way to sum it up is:

Linux offers RAID (classical RAID)
FreeNAS (FreeBSD not Linux) offers ZFS (Oracle/Sun Microsystem's solution for enterprise storage)

ZFS > RAID 5/6 in every which way, performance, data integrity, recovery, creation. The list continues, RAID 5/6 is just a mess.
ZFS Mirror > RAID 1 when it comes to data integrity, but RAID 1 has a slight performance advantage of ZFS Mirror.

ZFS is becoming increasingly popular in the enterprise space. The link above is a article by Anandtech where they compare a ZFS NAS to an enterprise hardware RAID system (in the R100K price tag range).

Then comes the second part.

Setup of Linux = Mission + hours of Googling, everything is tedious.
Setup of FreeNAS = Web-interface, everything is point & click, takes minutes if you use the tutorial as a guide.

To setup S.M.A.R.T monitoring of all your drives with error reports VIA email on Linux is a lot of work. On FreeNAS you click a few options.
To setup emailing if your software RAID is having problems in FreeNAS means filling out the email information, once again in Linux a mission.

The last part is sabNZBd. FreeNAS 8.2 is slated for release THIS month. The mayor change in FreeNAS 8.2 is plugin support.

Currently the 3 plug-ins available on the beta is sabNZBd, SickBeard & CouchPotato So you can bet that once the release is made end this month, it should have sabNZBd.

Lastly, running FreeNAS on an old PC:
You need a lot of RAM for FreeNAS (4GB minimum, 8GB recommended). CPU usage is not that critical but older PCs do tend to use a lot of power, so you might benefit by getting something like a HP Proliant Microserver which is low power.

If you have less than 4GB RAM, then give it a skip and go for Linux. FreeNAS won't even boot without 2GB and it'll be unstable with less than 4GB.

So I think I have fallen in love with ZFS

I am pretty used to running storage servers on extx with raid 1 & raid 5. I have endless issues with raid 5 it seems :/

Ive installed a 6TB raid array and it runs so quickly. Im loving the smart monitoring and easy to use cifs. They suggest using raid-z. From what I understand this is a better version of raid 5? Was hoping you could let me know a bit about that.

Im also curious about how the snapshots work. I assume theyre something like images? If I have 9 TB worth of data is the initial snapshot 9TB in size or is it compressed?

The short SMART self test that can be set to run hourly. Does that take the disks offline?

[Gnome]

Ive installed a 6TB raid array and it runs so quickly. Im loving the smart monitoring and easy to use cifs. They suggest using raid-z. From what I understand this is a better version of raid 5? Was hoping you could let me know a bit about that.

So I'll try keep this as simple as possible.

ZFS is a file system which also offers features that weren't usually handled by file systems (eg. redundancy, error checking, backup, etc.)

Each file in ZFS has a checksum (there is a lot of theory here but that checksum can virtually never clash unless the data is correct). So ZFS will always know if a file is damaged, regardless if you have redundancy setup.

ZFS has two types of redundancy, RAID-Z and Mirror. Mirror offers the same redundancy as RAID-1 but it is implemented completely and entirely different from RAID-1.

RAID-Z offers 3 levels. RAID-z1, RAID-z2, RAID-z3. Each level indicates the failure tolerance. Eg. z1 = single drive failure redundancy, z2 = double failure redundancy, vice versa.

Once again, RAID-Z is no way like RAID-5/6 in how it is implemented. Don't even think they are comparable, they aren't. RAID-z is superior in many ways with none of the weaknesses of RAID-5/6. There is a lot of theory around what is better and why and it would take pages to explain it so I won't go into that now. Suffice to say that RAID-5/6 CAN and WILL have data corruption, even the most expensive kind. It was in fact CERN that published a lot of research showing how much *silent* data corruption they suffered from their RAID-5 systems.

Apart from that Sun Microsystems recognized that RAID is not cheap and the controllers are falling behind development in the CPU & Memory fields. Even modern smart phones now rival some of the most expensive RAID controllers in processing power and memory bandwidth.

Currently there is no RAID-5/6 controller that could come even close to offering what you get with ZFS in terms of performance, price or any kind of measurement I can think of. Once again a lot of theory. If anyone thinks I'm wrong on this, I'll happily elaborate why you are wrong (yes I'm that confident ).

So you get the redundancy of RAID-5 (z1) or RAID-6 (z2) but at a much lower price and it also happens to have much lower chance of data loss or corruption.

Im also curious about how the snapshots work. I assume theyre something like images? If I have 9 TB worth of data is the initial snapshot 9TB in size or is it compressed?

ZFS doesn't compress a Snapshot.

ZFS does offer various forms of compression for the file system, and you should be turning it on. Disk IO is the slowest part of a NAS, so the higher your compression the better your throughput, that is if the CPU can keep up. I have compression enabled (the default compression) and my highest CPU usage is around 40% while maxing out a gigabit Ethernet connection.

So snapshots are very technical to explain but I'll try my best:

Essentially ZFS NEVER allows data to be overwritten. Instead data is written in a new place and the file system table is updated with the new location of a file. This is called Copy-On-Write. This also means if you have absolutely 0bytes left on your file system, you can no longer delete because it cannot modify data in place and you are screwed (so never let it get to 0bytes free). FreeNAS does offer you the option of reserving some disk space, I suggest you use that if you think you are going to use up all your space till you have 0 left.

Ok so a snapshot: It takes the file system table, makes a copy.

Any files that are deleted are still being kept track of by the file system table so it is not really removed from disk, until you remove that snapshot.

Essentially unless you delete a snapshot will take 0bytes of space or near 0 (if you just move files around).

It is very technical but if you are a programmer, it is like a linked list. And you make a copy of a link list and keep it around somewhere. A GC wouldn't collect the objects linked to that list until you get rid of that list. But essentially that list isn't costing you much memory because it just has references to objects.

Hope that explains it somewhat. If you are unsure about anything I have written ask away. And I welcome any hardcore I Love Hardware RAID guys to debate about why ZFS is better than hardware RAID in every way and why software RAID *will* replace hardware RAID (and is already doing so).

[Gnome]

The short SMART self test that can be set to run hourly. Does that take the disks offline?

Nope. Neither a short or long SMART test takes the disk offline.

In fact, it is pretty damned hard to take the array offline. My downtime is pretty much restricted to restarts during upgrade. During disk failures I've never had downtime (didn't even need to turn off the system to replace the disks, although it is recommended!).

Degraded or rebuilding I was still able to get 105megabytes/s over Ethernet (essentially max for gigabit) from and to my NAS (9x2TB RAID-z). The CPU usage however was around 70% while it was rebuilding the array. During the degraded state I noticed no difference in performance and CPU usage seemed the same.

What is more, I had 1 disk fail and another disk with bad sectors on my RAID-z1 (9x2TB) array.
Some of my files were lost but ZFS just warned me that about 3 MP3 files couldn't be completely recovered and probably contain errors.

RAID 5 would have failed there and stopped the rebuild because it needs all the blocks to complete a rebuild.

ZFS actually duplicates data. RAID takes all your data and creates a party (checksum). Therefore RAID is an all or nothing situation if a disk fails. RAID-z can have multi disk failure and then you will likely still be able to recover large amounts of data.