Linked by John Finigan on Mon 21st Apr 2008 19:00 UTC
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Are you, sir, suggesting that I lack real world experience? Well I never...!!
But seriously, there are a few points here which are worth responding to; a careful eye picks out some of the things I could have talked about, but cut to avoid the problem of too many themes in one article:
* There is an important difference between ZFS in Solaris and ZFS in OpenSolaris. OpenSolaris has all the latest and greatest ZFS features, Solaris not yet.
This is true, but frankly I find it unimportant in the last year or so since most of the ZFS features I consider important are in mainline Solaris, since, say, U4. A lot of the dev stuff is either icing, like gzip compression, or far-off alpha stuff, like on-disk encryption.
Sun does support Solaris, but does not offer support for the OpenSolaris builds. My opinion is that with regard to the risk of hitting bugs that the OpenSolaris developer edition builds can be compared to Linux kernel release candidates.
Sure. I, personally, would never recommend that anyone runs a dev version of an OS in a commercial setting. It's rarely worth the hassle.
If there are four filesystems to choose from, this means not every filesystem is suited for every workload. The article does not mention e.g. that when using a single disk, UFS performs better for database workloads than ZFS. This is not a coincidence but is due to the fundamental characteristics of these filesystems (see also Margo Seltzer e.a., File System Logging Versus Clustering: A Performance Comparison, USENIX 1995, http://www.eecs.harvard.edu/~margo/usenix.195).
I did allude to this. But I am not sure that that Seltzer paper is an applicable reference because I don't think that the designs of ZFS and LFS are close enough, ie, ZFS is not a pure-play log structured FS and requires no cleaner. I am not even sure the FFS comparison stands because journaling changes a lot, performance wise.
Still, the kernel of the argument is probably that ZFS and LFS both often change sequential IO to random and vice-versa, and this can cause weird performance characteristics. I think that this is true. However, experience (!) has taught me that single disk performance is rarely important, for the simple reason that almost any modern FS can max out a single disk on sequential and random. Putting it another way, if you require performance, you probably need more disks.
RE[2]: Background articles
by Abacus_ on Tue 22nd Apr 2008 16:26
in reply to "RE: Background articles"
* Sun does support Solaris, but does not offer support for the OpenSolaris builds. My opinion is that with regard to the risk of hitting bugs that the OpenSolaris developer edition builds can be compared to Linux kernel release candidates.
What does this mean then? http://developers.sun.com/sxde/support.jsp
Indiana is going to be named OpenSolaris (before that, OpenSolaris was just a code base). The developer edition (SXDE: "Solaris Express Developer Edition" built from OpenSolaris) is supported. The developer preview (aka Indiana) is just a preview.
Following up with your wording,SXDE is an OpenSolaris build.
I got what you meant, but the wording is incorrect.
RE[2]: Background articles
by Abacus_ on Tue 22nd Apr 2008 16:28
in reply to "RE: Background articles"
"* Sun does support Solaris, but does not offer support for the OpenSolaris builds. My opinion is that with regard to the risk of hitting bugs that the OpenSolaris developer edition builds can be compared to Linux kernel release candidates.
What does this mean then? http://developers.sun.com/sxde/support.jsp "
I was referring to end-user support, not to support for those who want to write OpenSolaris kernel or userland code.





Member since:
2006-12-08
Will we see more background articles on OSnews in the future ? These would be welcome. And it would be even better if such articles would be written by people with real-life experience. Although the article about Solaris filesystems is well written, some important facts are missing. A few examples:
* There is an important difference between ZFS in Solaris and ZFS in OpenSolaris. OpenSolaris has all the latest and greatest ZFS features, Solaris not yet.
* Sun does support Solaris, but does not offer support for the OpenSolaris builds. My opinion is that with regard to the risk of hitting bugs that the OpenSolaris developer edition builds can be compared to Linux kernel release candidates.
* If there are four filesystems to choose from, this means not every filesystem is suited for every workload. The article does not mention e.g. that when using a single disk, UFS performs better for database workloads than ZFS. This is not a coincidence but is due to the fundamental characteristics of these filesystems (see also Margo Seltzer e.a., File System Logging Versus Clustering: A Performance Comparison, USENIX 1995, http://www.eecs.harvard.edu/~margo/usenix.195).