ZFS - Building, Testing, and Benchmarking
by Matt Breitbach on October 5, 2010 4:33 PM EST- Posted in
- IT Computing
- Linux
- NAS
- Nexenta
- ZFS
Other Cool ZFS Features
There are many items that we have not touched on in this article, and those are worthy of mentioning at this time simply because they are enterprise features that are available with OpenSolaris and with Nexenta. These are features that the Promise M610i cannot compete with in any way.
Block Level Deduplication - ZFS can employ block level deduplication, which is to say it can detect identical blocks, and simply keep one copy of the data. This can significantly reduce storage costs, and possibly improve performance when the circumstances allow. One group that recently deployed a Nexenta instance had originally configured the system for 2TB of storage. They were using 1.4TB at the time and wanted to have room to grow. By enabling deduplication they were able to shrink the actual used space on the drives to just under 800GB. This also has implications when randomly accessing data. If you have multiple copies of the same data spread out all over a hard drive, it has to seek to find that data. If it's actually only stored in one place, you can potentially reduce the number of seeks that your drives have to do to retrieve the data.
Compression - ZFS also offers native compression similar to gzip compression. This allows you to save space at the expense of CPU and memory usage. For a system that is simply used for archiving data, this could be a great money and space saver. For a system that is being actively used as a database server, compression may not be the best idea.
Snapshot Shipping - OpenSolaris and Nexenta also offer snapshot shipping. This allows you to snapshot the entire storage array and back it up via SSH to a remote server. Once you ship the initial snapshot, only incremental data changes are shipped, so you can conserve bandwidth while still replicating your data to a remote location. Keep in mind that this is not a block level replication, but a point in time snapshot, so as soon as the snapshot is taken, any new data is not shipped to the remote system.
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Penti - Wednesday, October 6, 2010 - link
And a viable alternative still isn't available how is Nexenta and the community suppose to get driver support and support for new hardware there, when Oracle has closed the development kernel (SXDE is closed source), meaning that they maybe just maybe can use the retail Solaris 11 kernel if it's released in a functioning form that can be piped in with existing software and distro. They aren't going to develop it themselves and the vendors have no reason giving the code/drivers to anybody but Oracle. Continuing the OpenSolaris kernel means creating a new operating system. It means you won't get the latest ZFS updates and tools any more, at least not till they are in the normal S11 release. Means you can't expect the latest driver updates and so on either. You can continue to use it on todays hardware, but tomorrow it might be useless, you might not find working configurations.It's not clear that Nexenta actually can develop their own operating system, rather then just a distro, it means they have to create their own OS with their own kernel eventually. With their own drivers and so on. And it's not clear how much code Oracle will let slip out. It's just clear that they will keep it under wraps till official releases. It's however clear that there won't be any distro for them to base it on and any and all forks would be totally dependent on what Nexenta (Illuminos) manage to do. It will quickly get outdated without updates flowing all the time, and they came from Sun.
andersenep - Wednesday, October 6, 2010 - link
OpenIndiana/Illumos runs the same latest and greatest pool/zfs versions as the most recent Solaris 10 update.Work continues on porting newer pool/ZFS versions to FreeBSD which has plenty of driver support (better than OpenSolaris ever did).
A stated goal of the Illumos project is to maintain 100% binary compatibility with Solaris. If Oracle decides the break that compatibility, intentionally or not, it will truly become a fork. Development will still continue.
Even if no further development is made on ZFS, it's still an absolutely phenomenal filesystem. How many years now has Apple been using HFS+? FAT is still around in everything. If all development on ZFS stopped today, it would still remain an absolutely viable filesystem for many years to come. There is nothing else currently out there that even comes close to its feature set.
I don't see how ZFS being under Oracle's control makes it any worse than any other open source filesystem. The source is still out there, and people are free to do what they want with it within the CDDL terms.
This idea that just because the OpenSolaris DISTRO has been discontinued, that everything that went into it is no longer viable is silly. It is like calling Linux dead because Mandriva is dead.
Guspaz - Wednesday, October 6, 2010 - link
Thanks for mentioning OpenIndiana. I've been eagerly awaiting IllumOS to be built into an actual distribution to give me an upgrade path for my home OpenSolaris file server, and I look forward to upgrading to the first stable build of OpenIndiana.I'm currently running a dev build of OpenSolaris since the realtek network driver was broken in the latest stable build of OpenSolaris (for my chipset, at least).
Mattbreitbach - Wednesday, October 6, 2010 - link
I believe all of the current Hypervisors support this. Hyper-V does, as does XenServer. I have not done extensive testing with ESXi, but I would imagine that it supports it also.joeribl - Wednesday, October 6, 2010 - link
"Nexenta is to OpenSolaris what OpenFiler or FreeNAS is to Linux."FreeNAS has always been FreeBSD based, not Linux. It does however provide ZFS support.
Mattbreitbach - Wednesday, October 6, 2010 - link
I should have caught that - thanks for the info. I've edited the article to reflect as such.vermaden - Wednesday, October 6, 2010 - link
... with deduplication and other features, here You can grab an ISO build or a VirtualBox apliance here: http://blog.vx.sk/archives/9-Pomozte-testovat-ZFS-...It would be great to see how FreeBSD performs (8.1 and 9-CURRENT) on that hardware, I can help You configure FreeBSD for these tests if You would like to, for example, by default FreeBSD does not enables AHCI mode for SATA drives which increases random performance a lot.
Anyway, great article about ZFS performance on nice piece of hardware.
Mattbreitbach - Wednesday, October 6, 2010 - link
In Hyper-V it is called a Differencing disk - you have a parent disk that you build, and do not modify. You then create a "differencing disk". That disk uses the parent disk as it's source, and writes any changes out to the differencing disk. This way you can maintain all core OS files in one image, and write any changes out to child disks. This allows the storage system to cache any core OS components once, and any access to those core components comes directly from the cache.I believe that Xen calls it a differencing disk also, but I do not currently have a Xen Hypervisor running anywhere that I can check quickly.
gea - Wednesday, October 6, 2010 - link
new: Version 0.323napp-it ZFS appliance with Web-UI and online-installer for NexentaCore and Openindiana
Napp-it, a project to build a free "ready to run" ZFS- Web und NAS-Appliance with Web-UI and Online-Installer now supports NexentaCore and OpenIndiana (free successor of OpenSolaris) up from Version 0.323. With its online Installer, you will have your ZFS-Server running with all services and tools within minutes.
Features
NAS Fileserver with AFP (incl. Time Maschine and Zero Config), SMB with ACLs, AD-Support and User/ Groups
SAN Server with iSCSI (Comstar) and NFS forr XEN or Vmware esxi
Web-Server, FTP
Database-Server
Backup-Server
newest ZFS-Features (highest security with parity and Copy On Write, Deduplication, Raid-Z3, unlimited Snapshots via Windows previous Version, working ACLs, Online Pooltest with Datarefresh, Hybridpools, expandable Datapools=simply add Controller or Disks,............)
included Tools:
bonnie Pool-Performancetest
iperf Net-Performancetest
midnight commander
ndmpcopy Backup
rsync
smartmontools
socat
unzip
Management:
remote via Web-UI and Browser
Howto with NexentaCore:
1. insert NexentaCore CD and install
2. login as root and enter:
wget -O - www.napp-it.org/nappit | perl
During First-Installation you have to enter a mySQL Passwort angeben and select Apache with space-key
Howto with OpenIndiana (free successor of OpenSolaris):
1. Insert OpenIndiana CD and install
2. login as admin, open a terminal and enter su to get root permissions and enter:
wget -O - www.napp-it.org/nappit | perl
AFP-Server is currently installed only on Nexenta.
thats all, no step 3!
You can now remotely manage this Mac/PC NAS appliance via Browser
Details
www.napp-it.org
running Installation
www.napp-it.org/pop_en.html
Mattbreitbach - Wednesday, October 6, 2010 - link
Very neat - I am installing OpenIndiana on our hardware right now and will test out the Napp-it application.