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Reiser4 Benchmarks
unmadindu writes "Hans Reiser has benchmarked Reiser4 against ext3 and Reiserfs 3. Reiser4 turns out to be way faster than V3, and for ext3, why don't you check out the results yourself ? Hans Reiser states, "these benchmarks mean to me that our performance is now good enough to ship V4 to users", and he will be probably sending in a patch within the next couple of weeks to be included in the 2.6/2.5 kernel."
My one concern is reliability and recovery from failure; I've had a few cases where my belief in ReiserFS has been questioned; however I can't get Ext3 to build on larger than 500GB arrays.
At this point I'd happily choose based on reliability/recoverability/stability not raw speed.
Does anyone know if there will be a conversion utility available - i.e, to convert ReiserFS v3 partitions to v4?
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hey, I can live with an unstable gnome or Kicq, but a beta filesystem?? no thanks dude!
After reiser4, what filesystems are actually decent competition for it? It'd be nice for OSS to claim not only the best web server (apache), best kernel, and best filesystem.
Slashdot: Where people pretend to be twice as smart as they really are by behaving like children.
I am curious as to whether there are any projects to port Reiser4 to *BSD, particularly FreeBSD 5.x. Does anyone have any thoughts on how difficult a port might be? Can somone more versed in filesystems on *nix enlighten me as to the implimentation differences?
**AA: a bunch of mindless jerks who'll be the first against the wall when the revolution comes
In case anybody cares, "strelka" means "arrow", and "belca" means "squirrel"
Wonder what naming system they're using. I use names from Alice in Wonderland.
The statistics on that page are measured in seconds, no? So larger numbers are worse.
The comparisons are done with [foreign filesystem] divided by reiser4.
One would think that numbers greater than one, where the foreign filesystem has a long running time and reiser4 a short one, would be the ones that benefit reiser4.
Yet the numbers *less* than one are green, where Hans says reiser4 is considered better.
What's going on?
(Incidently, after having a friend lose a filesystem to buggy reiser code, I'm a bit inclined to wait until people have *seriously* hammered on this).
May we never see th
While great, this announcement/benchmark/statement does not mean that ReiserFS V4 is ready for production use, just that it is fast. It needs a lot more bug testing before then, so don't rush out and mass-convert to V4 just yet! See here for the full thread, rather than just the first post...
* Several monkeys are here, playing banjos and wearing small hats.
You'll probably have to compile it in yourself for now.
RH probably will include it in the future, but probably won't give you the option to install on it without jumping thru major hoops.
RH seems to suffer from a big case of "not-invented-here-itis", and RH users sometimes suffer for it. Not having ReiserFS is one way in which they do.
I realise that it is a bit early to adopt V4, but stable issues aside, which filesystem would YOU choose to for database volumes for fx. Oracle or MySQL?
my sig
Like "Three Dogs Playing Poker" to the Mona Lisa.
How does it compare against everyone's favorite, XFS?
Prescriptive grammar:linguistics
So he's submitting it to 2.6, but what are the chances it'll get submitted? Isn't this what caused all of Reiser's bitching a couple of years ago? He waited to long to get RFS into the kernel and ran into the feature freeze, and then pitched a hissy fit.
.
I'm not sure about the exact reasons why they don't support various other filesystems. The default bootup sequence of a RH system uses an initial ramdisk, and actually scans each partition available to find out where they should be mounted (they created nash, NAno SHell, which is just simple support for shell commands as well as fs label scanning). That's why you see the LABEL=/ in your /etc/fstab on a RH system. ResiserFS didn't support filesystem labels until 3.6, so using this setup could mess things up (with 3.5 or older), and justifies your point about having to "jump through hoops" to get reiserfs working. The simplest way I found to move to reiserfs was to change all the LABEL=??? specifications to actual device files, boot from a recovery disk, move everything around while reformatting the partitions as another filesystem, then finally rebooting.
Anybody know what, if any, features are being added for the laptop user? Last time a checked, journaled filesystems, like ext3, were generally a no-no if you wanted you battery to last.
Maybe a filesystem just for laptop/tablet pc users?
DELETE (time in secs to perform action)
:(
40.13(R4) 0.797 (ext3 journal) 0.837 (ext3)
woo-hoo! now it corrupts my data even quicker
http://milkshake.dexy.org
I know a lot of people will pull their hair out when they hear this, but: Speed is my primary concern. On long compiles of new programs or kernels for example the speed difference on a good FS can be important. I'm not saying that I'm willing to have a FS that corrupts every last file and directory, only that given two FSs which both have seemingly similar stability I would prefer the speed boost.
I have tried one or two of the FSs but I haven't used them for any length of time to be able to compare one against another.
The columns marked B/A and C/A are the performance ratios of ext3 data journaling and ext3 to reiserV4 respectively. A ratio greater than 1 means more time was needed for the operation than reiserV4 while a ratio less than 1 means faster performance.
I attended Hans' presentation at Linuxtag.
Basically, reiser4 is optimized for the case where you unpack a large tarball, say the Linux kernel, and have enough memory to hold it all in cache, which is true for most of us these days. reiser4 will then choose the optimal disk layout for these files and flush them to disk.
Hans also has aspects of a log structured file system in reiser4, which means you don't write to the file, you write to a log file which basically encompasses the whole disk. The up side is that you mostly write linearly, the down side is that the files get badly fragmented if they are updated at all. Most files are not updated, just written once at installation of the package. The files that are updated frequently tend to be source code from CVS, which are small enough to fit in memory completely and have reiser4 choose an optimal disk layout again.
The case where this model completely sucks is the case where you update many portions of a large file. For example, running an SQL database with files on a reiser4 file system as backend, or maybe a DNS server with DDNS, or a berkeley db backend for Postfix or qmail to keep the SMTP AUTH users or something. Also, log files will probably be badly fragmented.
Hans proposes to have something like a transparent defragmenter running in the background, which he calls "repacker". This would run in the kernel space, as part of the file system, and defragment badly fragmented files that are accessed frequently. This would solve most of the down sides of his approach, but this repacker is not finished yet.
My personal view of reiser4 is: it looks like it is optimized to perform well in benchmarks. It tries to be fastest for updating databases, but buys the performance by being slower when reading the data afterwards. The critical question is whether the repacker can alleviate these concerns, and as long as it is not finished, reiser4 is basically out of the question except for a little testing here and there. I reckon reiser4 would be a great filesystem for keeping your mozilla and gcc CVS checkout handy. But until the repacker is done, I will not even use it for testing, because the repacker really is the crucial component that makes or breaks this.
By the way: my previous experiences with reiserfs were less than stellar. Some people call it shredderfs instead. The main complaint with reiserfs is and always was that the fsck is not nearly as trustworthy or stable as the one from ext2/ext3. So even if I use reiserfs at all, it's only for data I can afford to lose completely, like my CVS checkouts or the squid cache directories or something like that.
The benchmarks do look good though, and I am glad that at least someone is still trying major innovations in this area. Since most Unix vendors or divisions are no longer profit centers, file system innovations have largely stalled or moved to specialized companies who regard them as proprietary (Veritas) instead of releasing them as free software like IBM and SGI did.
I know ext2 isn't a journal fs, but it would still be interesting to see a direct comparison again reiser4.
Marge, get me your address book, 4 beers, and my conversation hat.
It's still not time to swap it for ext3 for general use.
The first table with the mixed file sizes is the most compelling. The fact that reiser4's Create and Copy times are less than a third of the ext3s in real_time is impressive.
But the fact that the CPU consumption on Read is double that for R4 as it is for ext3 is a serious problem. On a 1.3 Ghz machine saturating a generic UDMA 100 60G bus on RH 9.0 it's about 10% of the CPU, so the home user might not care. For a system capable of delivering serious data (like a 4 drive, 15k rpm SCSI RAID array @~3 times the read throughput) going from 30% CPU to 60% CPU usage is a definite problem. Even with a 2.6 Ghz cpu it would still move from chewing up 15% to 30%. I know these numbers don't scale exactly, but they could in fact scale ugly depending on how much CPU is dedicated to communicating with the hardware and how much is in fiddling with the filesystem. My production boxes spend > 80% of their disk activity reading, so I'm not yet inspired to go out and spend the time running benchmarks on highperf. systems just yet.
Nevertheless, I always admire it when a new version of software comes out and it's noticeably faster than the old
That would be interesting.
that may be true for existing systems, but in the case of running an install from cd, instead of taking the default, add either "reiserfs" or "reiser" (don't remember which - think the "fs" one) to the boot options at the prompt when booting from the cd. it then adds reiserfs to the list of filesysems you can choose to format new filesystems with in the partitioning tool. pre-existing reiser filesystems will be handled correctly if you don't format them.
rh supports reiser just fine - they simply hide the option, probably because they feel ext3 is a safer choice.
Apple benchmarked their new G6 processor against the latest 10 GHz Pentium V. They say that despite its lower clock speed, it runs their suite of PhotoShop 8 filters almost four time faster than the Pentium.
Seriously, Hans Reiser is benchmarking his own file system, and he's using benchmarks that make his system look good. Like the SpriteLFS, his filesystem has a log structure for sequential writing, which makes it look really good in tests like he performed where you write the files once.
Compare a database load, where you write small chunks of big files all the time. Without the repacker (like the cleaner in LFS), the disk becomes horribly fragmented. With the repacker, you have to include the slowdown of this background process defragging your hard disk. Ick.
I'll trust his benchmarks when he presents a final, stable release, with the repacker on, and tests it under workloads such as would be encountered on a server. I might use it on my homebox even if it sucks on a server, but it would be nice to know that he considers his structure's impact on other workloads.
I hereby place the above post in the public domain.
> > they would just hit the reset button
>
> I've found users doing that to my servers before now. I find
> that hitting them on the nose with a rolled up newspaper and
> shouting "No! Bad monkey!" in a stern voice tends to stop this
> behaviour...
Even better: configure the services that the users use so that
they don't start up at system start. Write a short script that
starts them all, and whenever you restart the server ssh in and
run it. That way, if users cold-reset the server, nothing will
work until you fix it anyway, so you might be able to break them
of that habbit then. (Otherwise, they'll just do it behind your
back and not tell you; this way, they HAVE to come to you.) The
only internet service that needs to start at system start in such
a setup is sshd, and with that you can start up everything else
from anywhere easily.
If you have any coworkers (or underlings) clueful enough to handle
a shell prompt, you can train them to ssh in and do a _proper_
restart, and tell them how to start up all the services by running
your start-services script.
One more option: you can disconnect the reset switch. However,
that won't stop them from just unplugging it, which I've found
myself doing to Win9x systems when the reset switch does nothing,
or on some Linux systems when shutdown -h doesn't turn off the
power when it's finished, if there's no real power switch other
than the on-only kind a lot of newer cases sport.
So, just fix it so that doing Bad Things (like power-cycling)
doesn't achieve perceived positive results.
Cut that out, or I will ship you to Norilsk in a box.
That was V3. V4 is an atomic filesystem, which means that every filesystem operation is performed as a fully atomic transaction. This is more secure than the guarantees of data journaling, as data journaling doesn't necessarily guarantee that the write will complete.
The reason we are able to do this in V4 but not in V3 is that V4 uses what I call wandering logs. With wandering logs, instead of copying data first to the journal, and then after commit copying it from the journal to the rest of the filesystem, (thereby writing the data twice), we just change our definition of where the journal is. I don't think that data journaling is worth going half-speed for most users. With V4, we not only don't go half-speed, we go faster than V3 ever went.
For more details, please take a look at http:www.namesys.com/v4/v4.html
The first thing that popped into my head when I read that was "uh... feature freeze two weeks ago." I'm sure Reiser's going to have another of his babyish hissy fits. I see another slashdot story in the near future.
<Reiser> Oh, what about my sponsors! Why are you all playa hat'n on me?
<EveryoneNotOnTheReiserCheerleadingSquad> You don't get special treatment. You waited too long, and we're not putting your untested code into a frozen code base.
<Reiser> You're oppressing me! The GPLv3 will fix you all!
<SomeoneFromFSF> Please shut up, Reiser. You still don't know what the fuck you're talking about.
<Reiser> Wahh!! My sponsors!
<Everyone> SHUT UP REISER.
I'm as mimsy as the next borogove but your mome raths are completely outgrabe.
It is important that you use a distro that bases their kernel on 2.4.18, or later, when using ReiserFS. There exists a distro that bases their enterprise server kernel on 2.4.9, and intentionally declines to add any reiserfs bugfixes since then. (This is the same distro that once shipped their kernel with the ReiserFS debugging code turned on so that we would go slow.) Do NOT use their kernel with ReiserFS. Generally when someone reports that they are having really bad experiences with ReiserFS, it turns out they are using that kernel.
I generally recommend using the latest official kernel from Marcelo, and not any distro kernels, but the SuSE kernels tend to have effective ReiserFS support also, and not everyone out there shares my non-technical preference for a common community developed kernel.
Root is a prime candidate for a small (100MB should do it) ext2 system mounted "sync". You don't need decent write performance on root; in fact, many sysadmins make it read-only. Journalling is pointless if you're only writing to the filesystem once every 6 months to add a new user.
On the contrary, that's exactly the case where you should always journal, and with full data journalling. You don't care about write performance, since you hardly ever do it, but you do care at lot about keeping your root filesystem consistent.
Have you got your LWN subscription yet?
It's nice to have your log files mostly intact after a hard reboot, too.
I like the UFS2 FS for FreeBSD. Its stable but a little sluggish. I think it would be cool to have internal competition but the MS GPL == viral crap has made a dent into the BSD developers. They fear linking to anything gpl would make their kernel gpl as well.
Anyway this is just a pretty please with a cherry on top. Especially since you are being paid for by grants from DARPA who use Solaris, Linux, FreeBSD, and every Unix os under the sun.
http://saveie6.com/
I get reports (not verified by me) that ReiserFS V3 is an order of magnitude faster when used as a backend for an XML database than relational databases that were tried. So, if your data happens to have a hierarchical structure, or, you can put it into one, then you are likely to get a performance gain. If your data does not have a hierarchical structure, then you need to wait for V6 where we plan to expand the semantics.
If you want to be able to "cat filenameX/..owner" to see who owns "filenameX", you need to use V4.
I'm interested.
Are there features other than attributes provided by ext[23] which ReiserFS can't provide?
Regarding the attributes, ReiserFS can't do the following "useful" things:
- Excluding a single file from access-time logging.
- Append-only would be useful in certain cases.
- 'c' (compress file contents) -- Ext[23] doesn't do this yet, and ReiserFS doesn't either, but they both will support it later.
- 'D' (dirsync) attribute -- Other than ensuring that filesystem metadata operations are completed successfully before proceeding, I can't imagine a beneficial use of this attribute. ReiserFS already journals all metadata, and V4 journals everything (and does it faster).
- 'd' (do not back up using dump) -- AFAIK you can't use dump to back up a ReiserFS partition anyways, but tar still exists, and I'm sure there are wrapper scripts for the die-hard dump users.
- 'E' (error in compression) doesn't seem to apply to general (current) use of ext[23], and doesn't have an analogue in ReiserFS.
- 'I' (hash-indexed directory) -- ReiserFS' directory algorithms are much (much!) faster than ext[23]. ReiserFS will eventually support directory plugins, which allow one to set a per-directory hashing scheme. I note that ext[23] doesn't allow modification of this attribute, so I'm not sure if/how it allows you to choose a hashing scheme.
- Immutable ('i') bit -- This might be useful in some circumstances, such as a setuid binary. Not supported by ReiserFS.
- The 'j' option is meant to get around the fact that ext[23] only journals metadata unless mounted with "data=journal". As mentioned elsewhere, ReiserFS' long-term goal is to provide fully atomic file operations, which provides the benefits of data journalling with none of the burdens. Thus, ReiserFS V3 doesn't support this attribute, as the time spent in adding this feature would have been better spent working on V4. Note that with V4 all operations are atomic, which has the effect of turning this flag on for every file.
- 's' (zero file contents upon delete) -- ReiserFS doesn't support this.
- 'S' (write file synchronously) is likely used in cases where preserving file integrity is important. ReiserFS' journalling (especially in V4) provides this "for free".
- 'T' (top of directory heirarchy) is used to get around an ext[23] weakness. I don't recall details, but I believe it's something related to preventing fragmentation and grouping similar files together for enhanced performance. ReiserFS (especially V4) is already quite fast, and with code-level optimizations will likely get faster.
- 't' (don't merge tails) does not apply to current ext3 code, as tails aren't yet merged anyways. This will be used as a flag to write the file to disk in such a way as to be compatible with LILO and other boot loaders. At present I'm not aware of any special issues with ReiserFS' tail packing (which does exist, by the way) with respect to LILO. Note that a ReiserFS partition can be mounted with the "notail" option if you want, which is feature-wise equal to ext[23], which don't seem to provide tail packing at all right now (and if they do, someone needs to update the chattr man page).
- 'u' (back up upon deletion) -- ReiserFS doesn't support this.
- 'X' and 'Z' relate to compression, and do not apply to ext[23] or ReiserFS at the moment. ReiserFS will eventually support compression plugins, as well as encryption plugins.
So of the attributes, the only ones which might actually be of some use in the context of ReiserFS would be exclusion from atime logging, append-only, the immutable bit, zero-contents-upon-delete (although future crypto plugins will destroy the need for this feature), and back up upon deletion.
Anything I've missed?
Somebody get that guy an ambulance!