Category Archives: NAS O/S

FreeNAS, Openfiler, Microsoft iSCSI performance shootout

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freenas-ixsystems-new-logo

agrikk has taken a look at the performance capabilities of three free iSCSI Target software platforms: FreeNAS, Openfiler, and Microsoft iSCSI Target.

“The purpose of his test was to find the best performing iSCSI target with all other things being equal. Under this criteria alone, it would be a split decision between Openfiler and Microsoft.

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However, the Microsoft solution requires the purchase of a licensed copy of Windows 2008 R2 server to run its filer software so it isn’t exactly free. In addition, Openfiler can be run from a USB key, leaving all disks available for storage, where Microsoft cannot easily be run from anything other than a hard drive, taking up storage space for the OS.

With this added criteria, Openfiler emerges as the iSCSI champ.”

Have a look at the results here (warning: loads of graphs and screenshot): FreeNAS / Openfiler / Microsoft iSCSI performance shootout.

FreeNAS 8.3.1-RELEASE available

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freenas-ixsystems-new-logoThe FreeNAS development team has announced the availability of FreeNAS 8.3.1-RELEASE.

FreeNAS 8.3.1 is based on FreeBSD 8.3 with version 28 of the ZFS filesystem, and features volume based encryption for ZFS.

Release information, images and plugins can be downloaded from the Release Page. The Press Release with more details can be read here: iXsystems debuts exclusive ZFS Encryption Feature in FreeNAS 8.3.1

 

unRAID vs FlexRAID vs SnapRAID

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There is an interesting thread over on the AVS forums discussing the pros and cons of unRAID, FlexRAID and SnapRAID. They all have their advantages and disadvantages, and the following post bullet points them nicely.

Realtime protection:

  • unRAID and FlexRAID offer real-time parity
  • both only offer a single parity drive solution at this stage (both have plans for dual parity setups in real-time but who gets there first is anyone’s guess)
  • FlexRAID real-time is not as stable as unRAID for realtime parity (it does not handle anything that does not pre-allocate, and it hates Teracopy – author is aware of this issue)
  • Only unRAID offers simulated drive failures — all other solutions won’t offer up your lost files until you do a full repair

Drive pooling

  • FlexRAID and unRAID again both offer this functionality (optional in flexraid, but mandatory for realtime raid)
  • unRAID allows you to both view and operate on the individual drives that comprise the array without impacting realtime parity. Others only allow this functionality in Snapshot mode.

Shares

  • FlexRAID and unRAID handle sharing via their interfaces
  • SnapRAID etc. does sharing via the underlying OS

Performance

  • FlexRAID is the fastest for realtime
  • unRAID can incorporate a cache drive
  • I’m not sure of what the speed is like comparing snapshot parity between FlexRAID and SnapRAID (but am perfectly fine with the performance of SnapRAID)

Support

  • unRAID wins this by a country mile, the community is the most active and very helpful
  • SnapRAID and FlexRAID are also helpful, but suffer from lack of community participation

SnapShot protection

  • FlexRAID has no limit on how many parity drives you can employ
  • SnapRAID is limited to 2, but have plans for 3 drives in the future (probably distant future)

File integrity

  • unRAID does not have this feature
  • SnapRAID does checks on the block level
  • FlexRAID does checks on the file level

Thanks to hdkhang for summarising.

A first look at NZFS and replacing unRAID with NZFS’s Transparent RAID (tRAID)

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Brahim has added a blog post explaining  NZFS (Next-Generation Zion File System) and going into the the typical data storage problem: Optimal Capacity vs Optimal Performance vs Optimal Protection

NZFS can deal with the above limitations and “NZFS is implemented as a two part series:

  • A completely independent RAID system that works with any file system (use your favorite file system on top of it)
  • An optional File System designed to take greater advantage of the RAID system and provide advanced features such dedup, copy-on-write, checksuming, self-healing, etc. The file system component is optional because there are existing file systems such ReFS that provide some of the features the NZFS file system provides or the user might just not need those extra features. NZFS does not try to put you into a box unlike ZFS with its RAIDz system.”

The RAID system in NZFS has been designed in such a way that it can implement all standard RAIDs and many non-standard RAIDs, and on top of this, it supports Transparent RAID (tRAID). Transparent RAID is a better version of unRAID that runs on any modern version of Windows and Linux.

Brahim has also included a clear diagram showing how NZFS supercedes unRAID.

nzfs_traid_features

 

Read the whole post here: A first look at NZFS and replacing unRAID with NZFS’s Transparent RAID (tRAID)