Native ZFS for Linux
zfsonlinux.org
zfsonlinux.org
From the FAQ:
1.3 How do I mount the file system?
You can’t… at least not today. While we have ported the majority of the ZFS code to the Linux kernel that does not yet include the ZFS posix layer. The only interface currently available from user space is the ZVOL virtual block device.
Though you could get similar functionality by using membase at the expense of being limited to get/set operations (it's a K/V store).
That's some hard won knowledge there. :-)
(You can choose to cache assets meta-data only, but that tuning has major downsides itself and while it may protect your db, it's also likely to render your caches very under-utilized. Basically it isn't a silver bullet and it's still important to think of volumes and work-loads in terms of what "spindles" they're on.
So this is a port and therefor CDDL licesned and no able to be merged into the mainline Linux Kernel, right?
Is ZFS still a hot commodity with BTRfs just around the corner?
But even after a port, the underlying FS will have many more years of production use than brtfs. You might find bugs in the interface between the kernel and ZFS, but hopefully they wouldn't mess with any of the core fs code.
For instance, creating raid sets - by default it works with whole disks, which is exactly what you want 99% of the time (but you can specify a partition if you really want to).
Want to check whether there is a data corruption error?
"zpool scrub poolname" and it will go through all the disks on that pool, using the built-in ECC to verify that the data on the disks is OK. If not, it will try to fix it.
"zpool status -v" lists all the disks, which mirrors or RAID sets each is part of, and when the last scrub was performed, along with errors or ECC problems.
The one suggestion I would make for the btrfs guys is to really work on making the CLI commands simple and intuitive.
Also, since ZFS doesn't dedupe (just don't use it) or compress at rest, a scrub is the practical way to apply changes to those settings to the existing blocks already on disk.
[1]: http://www.linux-foundation.org/weblogs/amanda/2009/06/22/a-...
The other concern in that realm is that when you're centralizing storage concerns to lower costs, boost performance and increase reliability you don't want software issues or corruption to take down your entire business.
ZFS can be a painful enough learning curve when it comes to that environment. I wouldn't trust btrfs until it's been stable for a couple years there. And outside of that environment, there are plenty of good stable alternatives for the DAS space. While ZFS is nice there, and I'm sure btrfs would be as well, that's not the bread and butter for these systems.
ZFS has been around 4-5 years, yet in the last few months we hit a severe data loss bug (ZIL corruption) and a service affecting ZFS cache performance bug (ARC cache maintenance routine with math error).
I'd assume that btrfs will have similar teething pains.
Edit: I notice that a lot of people think ZFS is a cluster/distributed filesystem. I don't understand where they get this idea.
There is a problem on Amazon EC2, that you can mount EBS (Elastic Block Storage) only to one EC2 instance at a time.
I was told by several people (including some from Sun), that the only way to mount the same EBS instance to multiple EC2 instances is to use OpenSolaris and ZFS. I don't think this solution involves NFS.
Anyway now when ZFS almost ported to Linux, it would be great to check this issue again (requires ZPL).
What might work if you wanted to do this is to mount the EBS volume to an instance and then expose the volume using a network block device to multiple instances. Seems convoluted. Being able to attach EBS to multiple instances may be something Amazon will add if there is enough interest.
ZFS does make it easy to mirror multiple LUNs for redundancy though, so if you have a timeout or permanent disconnect from the device you remain operational. In addition detaching the device and moving it to another machine is trivial with zfs export/import commands.
Are web-hosting or shared-hosting providers using Ubuntu?
What do you thing Amazon or RackSpace are using?
RPM based distros generally have a tough standing since Ubuntu began to eclipse everything else in terms of popularity.
This search results showing that there are a lot of Linux home users who're using Ubuntu because it is most popular Desktop distro. Its popularity in a large extend due to money Canonical spent on promotion. (Remember free shipping of CD's and other actions)
But if you're considering a server segment, there are traditionally CentOS, RHEL or Fedora. Or even that stupid Unbreakable Linux. Why it is so? (Because it got that way!)
First, because most of really important key developers, like mr. Ulrich Drepper, works for RedHat or with Redhat. Redhat also actively supported by IBM, that's why RHEL is a such huge success.
Second, since RHEL4, when they made that stupid decision to maintain all the patches by themselves (RHEL4's kernel source rpm had up to 300 patches in it, but I'm not quite sure you know what it is all about.)
Now, they work with a mainstream kernel developers, so all their code got a most extensive testing possible. This is what Google's Linux engineers still cannot understand - the best testing and bug hunting is in primary linux source tree.
So, what about Ubuntu? Compared to Fedora it is outdated, very conservative, desktop-oriented distro for an average mediocre user. I don't want to go deeper and try to compare source packages of key components, such as kernel, glibc and related, but I'm pretty sure there are different set of patches. One can compare common packages like perl, python, erlang, gcc, php by themselves.
Conclusion? OK, 3-5 years ago using Ubuntu or Debian as a server instead of Fedora-derived distros was a sign of non-professionalism, if not a fanboyism or even ignorance. What changed today? Almost nothing. Ubuntu is following the same conservative policies. There are some so-called server editions of Ubuntu, but it is rather a marketing movement.
And, you might be surprised, but key kernel developers are using Fedora. =)
Funny. In my circles it's considered a sign of masochism to run a RPM based distro in this day & age. To each their own, let's keep the evangelism off HN.
I'm trolling because I was around when FreeBSD 2.0 was considered as too modern, when there were no RedHat, let alone Ubuntu. I survived migrations from libc5 to glibc, from LinuxThreads to NTPL, from 2.4 to 2.6 kernels. I made a specialized distros for corporate usage from RH's and then RHEL4's srpms long before CentOS was here. I did a migration of Informix-based products from SCO Open Server to Linux in 1999 as a solution for so-called problem 2000.
Now, when any newfag without any understanding of what depends of what and why it is so, can do yum install or apr-get install php* what should I do?
I'm still unable to comprehend what mc is or what nautilus is for. I'm still using only 5 programs - vi, emacs, mit-scheme, chromium and mplayer, and have an addiction for rebuilding anything with clang.
So, seems like I'm a troll. In this case yes, I'm trolling.