Crying “FUD” doesn’t always mean you’re right

…and it sure doesn’t grant you instant vindication.

It appears that DaveM (Linux networking and SPARC port guru) has gotten seriously wound up in response to a blog post by Jeff Bonwick (Sun’s storage and kernel guru.)

As one can see in Jeff’s post, the suject he wrote about was within the greater context of using Solaris as a storage appliance OS (something I have an interest in) and why Solaris/OpenSolaris can and would excel when it comes to being the kernel of a storage OS.

I’m a storage guy. In the course of my work I have to not only work with Solaris hosts on my SAN, but also Windows and Linux (and soon, AIX). So I have a front-row seat when it comes to witnessing and dealing with how these various OSes deal with storage, from the filesystem to multipathing, to the HBA… and let me tell you, Linux is quite not the joy in this specific area as most people think it is on a general, all-encompassing level.

And that’s what Jeff’s angle was.

Now on to Dave’s rebuttle.

“The implication is that Linux is not rock-solid and that it does break and corrupt people’s data. Whereas on the other hand Solaris, unlike the rest of the software in this world, is without any bugs and therefore won’t ever break or corrupt your data.”

No OS comes without fault, but some OSes have faults that are more glaring than others in their analogous areas. Staying within the storage context of this discussion, I have to say, again, Linux is no shining star here.

ReiserFS is arguably the most advanced fs in terms of features when it comes to the portfolio of Linux file systems, but its issues with stability are such that you’re really walking on eggshells whenever you employ it. I have been personally told too many first-hand accounts and read plenty more on the Internets regarding its tendency to be fine and then fail spectacularly. It has been likened to a time-delayed /dev/null of sorts, and the future of it is in doubt with the legal troubles of its designer and Namesys limbo. Is any version of ReiserFS a viable Linux storage technology for a production environment? I say No. That’s sad because I dare say at one point ReiserFS had some promise.

EXT2 and 3… tried and true. Very stable and moderately fast for most tasks. But it’s an “old guard” file system. As such, it’s not very flexible, and any flexibility it gets comes from using a volume manager underneath of it. In the days where the notion of handing a server a 1TB LUN is nothing to blink at, this inflexibility can be suffocating in a dynamic environment. These “old guard” file systems (yes, Solaris’s UFS is one of them, too) are more like mere utility file systems than practical ones for today’s mass storage needs. It’s good for holding a machine’s OS and that’s about it.

XFS… Of all the file systems in the Linux file system portfolio, this one gets the gold star. Stable, fast, and decently scalable with the large amount of data you can stuff in it… but it still suffers the same problems EXT[23] and other “old guard” file systems do in terms of flexibility. In other words, it’s just a file system. Keep in mind that this critique is coming from a guy who worked with XFS on IRIX often and absolutely loved XLV… back in its the day.

As it stands now, the mainline Linux kernel doesn’t offer anything which embodies the file system triple play: being stable && fast && flexible. Solaris’s ZFS has this. I’ve so far entrusted 30TB of spinning rust to it, and it has yet to let me down. Sure, there are projects here and there that have the eventual goal endowing Linux with a ZFS analog, but as of right now they’re nothing production quality and are definitely not something a admin can call RedHat to get support for.

There are plenty of other aspects to the storage context… the fibre channel stack, for one, and other things such as multipath IO implementations and volume manager and management layers (which Linux has a host of… not necessarily a good thing… LVM, LVM2, MPIO, RDAC… it makes your head spin.)

But as far as this storage-oriented discussion goes, file systems are indeed the make or break aspect. This is why Jeff said what he said. Linux has no ZFS. Windows has no ZFS. It is not that Linux or Windows need ZFS itself in order to compete, it’s that they need to develop and employ the concepts that ZFS implements and do so as clearly and concisely as ZFS has.

Anyway, enough about storage. Now, why is it that the Linux community (let alone a prominent member of it) has to react so violently to any questioning of its perceived superiority? Is it misplaced or excess pride? Have they not tried things other than Linux recently and they’re just flying with blinders on? Is it just the social culture which prevails within it? What ever it is, seeing posts like Dave’s makes my toes curl with embarrassed amazement.

A friendly message to Dave: Chill the ad hominems, mkay? Crying “FUD!” at the mere sight of someone who you perceive as poo-poo’ing an aspect of your interest doen’t typically translate into a well thought-out rebuttle. You took the low road and tried to convey Jeff as being some instrument of some nefarious, Mr. Burns-like person at Sun. Is vilifying instead of cool-headed technical discourse really your desired style? Has anyone come biting at you saying “oh, he’s a Linux kernel developer, so he has an agenda”?

2 Replies to “Crying “FUD” doesn’t always mean you’re right”

  1. That’s “rebuttal”.

    Your captcha is insufficiently intelligent. It didn’t recognize “Eleven” as an answer to “please add 5 and 6”. Ah well, I knew what it meant.

  2. This is 100% correct. I said it once on the ZFS list as well. If Linux or other OSes can’t seem to get ZFS due to licensing or other stupid reasons, there is no reason why the same concepts can’t be employed (besides possible oddball patent stuff.) At least the integrity checking and self-healing functions should be open for implementation, and I don’t see why things like COW and inline checksumming couldn’t be implemented at least to ensure data correctness. The whole pooled storage model is cool too, but the first step would definately be a welcome option. I use XFS myself, it has crashed a couple times (but recovered…) BTRFS for Linux looks promising…

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