Linked by John Finigan on Mon 21st Apr 2008 19:00 UTC
Oracle and SUN When it comes to dealing with storage, Solaris 10 provides admins with more choices than any other operating system. Right out of the box, it offers two filesystems, two volume managers, an iscsi target and initiator, and, naturally, an NFS server. Add a couple of Sun packages and you have volume replication, a cluster filesystem, and a hierarchical storage manager. Trust your data to the still-in-development features found in OpenSolaris, and you can have a fibre channel target and an in-kernel CIFS server, among other things. True, some of these features can be found in any enterprise-ready UNIX OS. But Solaris 10 integrates all of them into one well-tested package. Editor's note: This is the first of our published submissions for the 2008 Article Contest.
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RE: Comment by agrouf
by sbergman27 on Tue 22nd Apr 2008 15:49 UTC in reply to "Comment by agrouf"
sbergman27
Member since:
2005-07-24

ZFS is good, but layered ZFS would be better, for many reasons. Can ZFS do reiserfs over LVM over RAID over NFS, SMB and gmailfs? You would be surprised how some people use the technology sometimes.

It's not just that. It's maintainability. When features get added to the wrong layer, it means code redundancy, wasted developer effort, wasted memory, messy interfaces, and bugs that get fixed in one filesystem, but remain in the others.

It does make a difference just how many filesystems you care about supporting. The Linux philosophy is to have one that is considered standard, but to support many. If Sun is planning for ZFS to be the "be all and end all" filesystem for *Solaris, it is easy to see them coming to a different determination regarding proper layering. Neither determination is wrong. They just have different consequences.

Perhaps btrfs will someday implement all of ZFS's goodness in the Linux Way. I confess to being a bit impatient with the state of Linux filesystems today. But not enough to switch to Solaris. I guess one can't expect to have everything.

Reply Parent Score: 3

RE[2]: Comment by agrouf
by jwwf on Tue 22nd Apr 2008 16:31 in reply to "RE: Comment by agrouf"
jwwf Member since:
2006-01-19

It's not just that. It's maintainability. When features get added to the wrong layer, it means code redundancy, wasted developer effort, wasted memory, messy interfaces, and bugs that get fixed in one filesystem, but remain in the others.

It does make a difference just how many filesystems you care about supporting. The Linux philosophy is to have one that is considered standard, but to support many. If Sun is planning for ZFS to be the "be all and end all" filesystem for *Solaris, it is easy to see them coming to a different determination regarding proper layering. Neither determination is wrong. They just have different consequences.

Perhaps btrfs will someday implement all of ZFS's goodness in the Linux Way. I confess to being a bit impatient with the state of Linux filesystems today. But not enough to switch to Solaris. I guess one can't expect to have everything.


This is a good, balanced explanation. I think the question is whether the features provided by ZFS are best implemented in a rethought storage stack. In my opinion, the naming of ZFS is a marketing weakness. I would prefer to see something like "ZSM", expanding to "meaningless letter storage manager". Calling it a FS makes it easy for people to understand, but usually to understand incorrectly.

I see ZFS as a third generation storage manager, following partitioned disks and regular LVMs. Now, if the ZFS feature set can be implemented on a second generation stack, I say, more power to the implementors. But the burden of proof is on them, and so far it has not happened.

I too am impatient with the state of Linux storage management. For better or worse, I just don't think it is a priority for the mainline kernel development crew, or Red Hat, which, like it or not, is all that matters in the commercial space. I think ext3 is a stable, well-tuned filesystem, but I find LVM and MD to be clumsy and fragile. Once ext4 is decently stable, I would love to see work on a Real Volume Manager (tm).

Reply Parent Score: 4

RE[3]: Comment by agrouf
by DirtyHarry on Tue 22nd Apr 2008 19:27 in reply to "RE[2]: Comment by agrouf"
DirtyHarry Member since:
2006-01-31

[q]I too am impatient with the state of Linux storage management. For better or worse, I just don't think it is a priority for the mainline kernel development crew, or Red Hat, which, like it or not, is all that matters in the commercial space. I think ext3 is a stable, well-tuned filesystem, but I find LVM and MD to be clumsy and fragile. Once ext4 is decently stable, I would love to see work on a Real Volume Manager (tm).


I think you wrong here. I do think the Linux kernel community is aware of the desperate need of a 'kick-ass-enterprise-ready-filesystem-like-ZFS'. A lot of people where waiting for the arrival of Reiser4, but we all know how that ended :-)

Ext4 is just a 'let's be pragmatic' solution: we need something better than Ext3.

ZFS for Linux is (besides license issues) a 'no-go' because of the (VFS) layering stuff.

But I think that there's hope: BTRFS. It doesn't sound as sexy as ZFS, but it has a lot to offer when it becomes stable and available. I'm following the development closely, and I get the idea that Chris Mason makes sure to not fall into the 'reiser trap' by communicating in a constructive matter with the rest of the kernel community.

Although not ready in the near future (read 2008), I personally have high expectations of BTRFS. And I believe it will become the default filesystem for many distributions when it arrives.

Regards Harry

Reply Parent Score: 1

RE[3]: Comment by agrouf
by segedunum on Tue 22nd Apr 2008 23:05 in reply to "RE[2]: Comment by agrouf"
segedunum Member since:
2005-07-06

I too am impatient with the state of Linux storage management.

I don't see many people sharing your impatience in all honesty. The software RAID subsystem within Linux is pretty good, and has been tested exceptionally well over and over again over a number of years. You need to have spent a reasonable amount of money on a pretty decent hardware RAID set up if you really want something better. That extends to ZFS as well, as software RAID by itself can only take you so far.

The only perceived problem is that you don't get volume management, RAID and other storage management features for free in one codebase. If distributions started partitioning by using LVM by default, created userspace tools that had a consistent command line interface, as well as GUI tools that made LVM and software RAID much more visible and usable, then you'd see them more widely used on a wider variety of systems.

...but I find LVM and MD to be clumsy and fragile.

You're going to have to qualify that one, because LVM and MD software RAID were stable and being used before ZFS was even a glint in Bonwick's eye. Indeed, ZFS has yet to be proven in the same way.

I would love to see work on a Real Volume Manager (tm).

You'll probably see one come about when it becomes a requirement to do storage management on running desktop systems and other appliances. Until that day arrives those who require the features of ZFS are already using hardware RAID and some form of volume management, and beyond that, something like the Veritas Storage System.

That's part of the fallacy I see in some of the hype surrounding ZFS. It's useful and a nice thing to have, especially when compared with what you got in Solaris before, but its significance is overplayed. Most of what's in there is only really useful to people with some pretty large storage arrays, and if you have something that matters to you then you'll already be running hardware RAID of some description and volume management, and if you have money riding on it then you'll use Veritas as they have the tools that make the thing really useful, and it's very well proven having been around for the best part of two decades.

When we do get to a stage where desktop systems and various appliances need these storage capabilities (real home entertainment systems, whenever they actually happen) we'll have far better and affordable solid state or holographic storage, and the vast majority of what ZFS provides that is useful will have been transparently rolled into the hardware and not even software and kernel developers will need to worry about it.

To conclude, ultimately, when it comes to storage management today, we are limited by the hardware and the storage mediums that we have. You can't polish a turd by slapping ZFS on it, no matter how much self-healing goes on.

Reply Parent Score: 2