Re: [zfs-discuss] utf8only-property
So, I set utf8only=on and try to create a file with a filename that is a byte array that can't be decoded to text using UTF-8. What's supposed to happen? Should fopen(), or whatever syscall 'touch' uses, fail? Should the syscall somehow escape utf8-incompatible bytes, or maybe replace them with ?s or somesuch? Or should it automatically convert the filename from the active locale's fs-encoding (LC_CTYPE?) to UTF-8? First, utf8only can AFAIK only be set when a filesystem is created. Second, use the source, Luke: http://src.opensolaris.org/source/search?q=defs=refs=z_utf8path=%2Fonnv%2Fonnv-gate%2Fusr%2Fsrc%2Futs%2Fcommon%2Ffs%2Fzfs%2Fzfs_vnops.chist=project=%2Fonnv Looks to me like lookups, file create, directory create, creating symlinks, and creating hard links will all fail with error EILSEQ (Illegal byte sequence) if utf8only is enabled and they are presented with a name that is not valid UTF-8. Thus, on a filesystem where it is enabled (since creation), no such names can be created or would ever be there to be found anyway. So in that case, the system is refusing non UTF-8 compatible byte strings and there's no need to escape anything. Further, your last sentence suggests that you might hold the incorrect idea that the kernel knows or cares what locale an application is running in: it does not. Nor indeed does the kernel know about environment variables at all, except as the third argument passed to execve(2); it doesn't interpret them, or even validate that they are of the usual name=value form, they're typically handled pretty much the same as the command line args, and the only illusion of magic is that with the more widely used variants of exec that don't explicitly pass the environment, they internally call execve(2) with the external variable environ as the last arg, thus passing the environment automatically. There have been Unix-like OSs that make the environment available to additional system calls (give or take what's a true system call in the example I'm thinking of, namely variant links (symlinks with embedded environment variable references) in the now defunct Apollo Domain/OS), but AFAIK, that's not the case in those that are part of the historical Unix source lineage. (I have no idea off the top of my head whether or not Linux, or oddballs like OSF/1 might make environment variables implicitly available to syscalls other than execve(2).) This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Performance with Sun StorageTek 2540
On Wed, 27 Feb 2008, Cyril Plisko wrote: http://www.simplesystems.org/users/bfriesen/zfs-discuss/2540-zfs-performance.pdf Nov 26, 2008 ??? May I borrow your time machine ? ;-) Are there any stock prices you would like to know about? Perhaps you are interested in the outcome of the elections? No need for a time machine, the US presidential election outcome is already known: http://www.theonion.com/content/video/diebold_accidentally_leaks Paul ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] zpool core dumped
S10U4 SPARC on V890 + patches, StorageTek 6140 + CSM200 Generic_127111-09 The same issue, still don't patched ? If I set NOINUSE_CHECK=1 pool is created succesfully Regards -- Piotr (DrFugazi) Tarnowski This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Can ZFS be event-driven or not?
[i]Consider this to be your life's mission.[/i] Bob, I can do without this. Richard, [i]Actually I use several browsers every day. Each browser has a cache located somewhere in my home directory and the cache is managed so that it won't grow very large. With CDP, I would fill my disk in a week or less, just by caching everything on the internet that I pass by.[/i] if you RTFT, you'd find that nobody ever was interested in temp files. [i]In Uwe's use cases thus far, it seems that he is interested in only the simple single user style applications, if I'm not mistaken, so he's not considering the consequences of what it *really* means to have CDP in the way he wishes. Uwe - am I close here?[/i] Nathan, you are not. Again, there's nothing that I wanted. I was only thinking. And I am a server person. Now, if I switch from the /export/home/userfoo/Documents (for Richard, who might be happier with UZFS-CDP than with the shots of TimeMachine), to a file server, do the arguments still hold, that 1. The application (NFS - sftp) does not know about the state of writing? 2. Obviously nobody sees anything in having access to all versions of a file stored there? In any case, my presentation at that enterprise-security related conference is done, the 'history' of backups presented (not exactly my topic). I introduced the idea of versioning, and the (possible) advantages of having all versions, including the (possible) disadvantages (storage space, mentioned despite my doubts). I also pointed out the currently available software for near-CDP, and mentioned the discussion we have in here; started for one and only reason (see Subject): to confirm if ZFS can be instructed to produce a copy of each version of a file, initiated by some event instead of a scheduler. Somewhat to my surprise, my presentation was a good success, and QA was focused on the event-driven backups, what the technical problems were, etc. A good handful of people approached me later, being curious and fascinated by the idea to replace the backup scheduler with an event-driven creation of the versions. Therefore, to me the case is closed; my presentation done, on the successful side. Thanks to everyone who cared to answer, help, contribute in one way or another, Uwe This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS vs. Novell NSS
Alan Perry wrote: Alan Perry wrote: I gave a talk on ZFS at a local user group meeting this evening. What I didn't know going in was that the meeting was hosted at a Novell consulting shop. I got asked a lot of what does ZFS do that NSS doesn't do questions that I could not answer (mostly because I know almost nothing about Novell). Is there some white paper or something on the topic? I googled for Novell NSS and went straight to the Overview: http://www.novell.com/documentation/nw65/nss_enu/data/hut0i3h5.html#hut0i3h5 NSS abstracts up to four physical NetWare partitions to make them appear as contiguous free space ZFS can abstract many more than four of anything to make them appear as continguous free space. ZFS can be used on Solaris for SPARC, Solaris for X86, and soon to be on the Mac, and anywhere else where people decide to port ZFS. You can choose space from at least four devices of up to 2 TB each to create a pool with a maximum pool size of 8 TB. [and more stuff describing limitations of NSS right off the bat] You can make ZFS pool of any nymber of device, the max file size of ZFS is in exabytes, max pool size is some ridiculously big number. Checksumed, open and free, yada yada. How about that to start? CT ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Can ZFS be event-driven or not?
A good handful of people approached me later, being curious and fascinated by the idea to replace the backup scheduler with an event-driven creation of the versions. Uwe, I'm still struggling to decide if ADM is what you're looking for. When you make comments like the one quoted above, I think ADM is a very practical choice for you. Even if it isn't, the issues discussed here are what lead people to an ADM-like solution. Let me attempt to summarize the dilemmas as I see them, and point out the practicality of an ADM-like solution... * Application agnostic CDP cannot know when the file state is sane. For true CDP this essentially requires preserving the entire write stream, which is an enormous burden (in both storage capacity and system bandwidth). Presumably this burden is unacceptable except in niche cases. Basically: it works, but it hurts. * Application aware/driven CDP solves the file sanity challenge by being explicitly told by the app. But this will have an inherently limited market because it relies on application support. Basically: it works, but requires coordination rarely found outside monopoly owned stacks. * Traditional backup leaves exposure windows and doesn't address the file sanity issue (unless there is a backup window, or specific assumptions) Basically: its easy because it overlooks so much. Unless you have a large budget, some compromises need to be made. IMO, ADM is a reasonable compromise for many. With ADM, backing up files is typically initiated at a specified time after file modification. For this discussion, think of it as: “make a new backup anytime file data is stable for X amount of time”. There can be many policies for files with different usage patterns in a file system. These should be tailored to business value, anticipated modification frequency, etc. Here's a few examples of policies one might set up: - Never backup files with /firefox/cache/ in the path. - Backup (to disk) the CEO's Star-Office docs when they're stable for 1 minute. - Backup (to disk) other user's Star-Office docs when they're stable for 5 minutes. - Backup (to disk) all other files when stable for 5 hours. - Make a second backup (to tape) of all files when they're stable for 24 hours. Note how the file data stability time can ignorantly handle the file consistency issue. Pauses in file modification should generally occur when the data is consistent. If not, we'll back it up again anyway after the next round of modifications. The overhead introduced by ADM is less than you might imagine... ADM/DMAPI can enable specific event types on a per-filesystem-object basis, so the versatility of the policies above does not come at the expense of excess chatter. ADM's evaluation of a file is triggered by a change or close event. So we look when there is reason to be believe we have work to do. ADM has several benefits relevant to this discussion: - Automated management of the thousands/millions of backups. How many to keep, should they be migrated from disk to tape, etc. - Automated reclaiming reuse of media used for backups. - No burden of maintaining entire write stream - No requirement for application support - For most file access patterns, we should make good guesses on when the data is consistent. If you're willing to give up the “last mile” requirement of CDP ADM is a fairly cheap way to give you a lot of what you want. Thoughts? (in ADM we use the term “archive” but here I'm using the term “backup” since that's what you're using) -Joe This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Can ZFS be event-driven or not?
On Thu, 28 Feb 2008, Uwe Dippel wrote: 1. The application (NFS - sftp) does not know about the state of writing? Sometimes applications know about the state of writing and sometimes they do not. Sometimes they don't even know they are writing. 2. Obviously nobody sees anything in having access to all versions of a file stored there? First it is necessary to determine what version means when it comes to a file. At the application level, the system presents a different view than what is actually stored on disk since the system uses several levels of write caching to improve performance. The only time that these should necessarily be the same is if the application uses a file descriptor to access the file (no memory mapping) and invokes fsync(). If memory mapping is used, the equivalent is msync() with the MS_SYNC option. Using fsync() or msync(MS_SYNC) blocks the application until the I/O is done. If a file is updated via memory mapping, then the data sent to the underlying file is based on the system's virtual memory system so the actually data sent to disk may not be coherent at all. Bob == Bob Friesenhahn [EMAIL PROTECTED], http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer,http://www.GraphicsMagick.org/ ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Can ZFS be event-driven or not?
On Thu, Feb 28, 2008 at 07:55:45AM -0800, Joe Blount wrote: * Application aware/driven CDP solves the file sanity challenge by being explicitly told by the app. But this will have an inherently limited market because it relies on application support. Basically: it works, but requires coordination rarely found outside monopoly owned stacks. I challenge the assumption that this has an inherently limited market -- if you get momentum for something like this then who knows, it might take off. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Can ZFS be event-driven or not?
On Wed, 2008-02-27 at 13:43 -0500, Kyle McDonald wrote: How was it MVFS could do this without any changes to the shells or any other programs? I ClearCase could 'grep FOO /dir1/dir2/file@@/main/*' to see which version of 'file' added FOO. (I think @@ was the special hidden key. It might have been something else though.) When I last used clearcase (on the order of 12 years ago) foo@@/ only worked within clearcase mvfs filesystems. It behaved as if the filesystem created a foo@@ virtual directory for each real foo directory entry, but then filtered those names out of directory listings. Doing the same as an alternate view on snapshot space would be a simple matter of programming within ZFS, though the magic token/suffix to get you into version/snapshot space would likely not be POSIX compliant.. - Bill ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] path-name encodings
Bart Smaalders [EMAIL PROTECTED] wrote: I'm unable to find more info about this. E.g., what does reject file names mean in practice? E.g., if a program tries to create a file using an utf8-incompatible filename, what happens? Does the fopen() fail? Would this normally be a problem? E.g., do tar and similar programs convert utf8-incompatible filenames to utf8 upon extraction if my locale (or wherever the fs encoding is taken from) is set to use utf-8? If they don't, then what happens with archives containing utf8-incompatible filenames? Note that the normal ZFS behavior is exactly what you'd expect: you get the filenames you wanted; the same ones back you put in. OK, thanks. I still haven't got any answer to my original question, though. I.e., is there some way to know what text the filename is, or do I have to make a more or less wild guess what encoding the program that created the file used? OK, if I use utf8only then I know that all filenames can be interpreted as UTF-8. However, that's completely unacceptable for me, since I'd much rather have an important file with an incomprehensible filename than not have that important file at all. Also, what about non-UTF-8 encodings? E.g., is it possible to know whether 0xe4 is ä (as in iso-8859-1) or ф (as in iso-8859-5)? The trick is that in order to support such things as casesensitivity=false for CIFS, the OS needs to know what characters are uppercase vs lowercase, which means it needs to know about encodings, and reject codepoints which cannot be classified as uppercase vs lowercase. I don't see why the OS would care about that. Isn't that the job of the CIFS daemon? As a matter of fact I don't see why the OS would need to know how to decode any filename-bytes to text. However, I firmly believe that user applications should have that opportunity. If the encoding of filenames is not known (explicitly or implicitly) then applications don't have that opportunity. - Marcus ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS vs. Novell NSS
On 2/28/08, Christine Tran [EMAIL PROTECTED] wrote: Alan Perry wrote: Alan Perry wrote: I gave a talk on ZFS at a local user group meeting this evening. What I didn't know going in was that the meeting was hosted at a Novell consulting shop. I got asked a lot of what does ZFS do that NSS doesn't do questions that I could not answer (mostly because I know almost nothing about Novell). Is there some white paper or something on the topic? I googled for Novell NSS and went straight to the Overview: http://www.novell.com/documentation/nw65/nss_enu/data/hut0i3h5.html#hut0i3h5 NSS abstracts up to four physical NetWare partitions to make them appear as contiguous free space ZFS can abstract many more than four of anything to make them appear as continguous free space. ZFS can be used on Solaris for SPARC, Solaris for X86, and soon to be on the Mac, and anywhere else where people decide to port ZFS. You can choose space from at least four devices of up to 2 TB each to create a pool with a maximum pool size of 8 TB. [and more stuff describing limitations of NSS right off the bat] You can make ZFS pool of any nymber of device, the max file size of ZFS is in exabytes, max pool size is some ridiculously big number. Checksumed, open and free, yada yada. How about that to start? CT ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss Don't forget, ZFS is open source, and can be ported to any other number of platforms as well. It's also currently supported on FreeBSD 7.0, and is basically production ready on that platform. The open source is HUGE in my mind, you aren't tied to Solaris. Granted, that is where the main development is taking place right now, but if Sun were to fold up shop, or kill off solaris *cough*netware*cough*, zfs isn't going anywhere, and your data should be portable. I'm going to be blunt, and probably will rile up a few trolls if there are any on this mailing list: If you're talking to anyone still on netware, they're a netware zealot, and nothing you can say is going to change that. If they haven't found a reason to throw netware under the bus yet, they aren't going to. No reasonable argument as to why ZFS is superior to NSS will be heard, there will always be some caveat (ITS NOT SUPPORTED BY NOVELL!!!11), as to why it's just not a good enough reason to switch. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Can ZFS be event-driven or not?
Bill Sommerfeld wrote: On Wed, 2008-02-27 at 13:43 -0500, Kyle McDonald wrote: How was it MVFS could do this without any changes to the shells or any other programs? I ClearCase could 'grep FOO /dir1/dir2/file@@/main/*' to see which version of 'file' added FOO. (I think @@ was the special hidden key. It might have been something else though.) When I last used clearcase (on the order of 12 years ago) foo@@/ only worked within clearcase mvfs filesystems. It behaved as if the filesystem created a foo@@ virtual directory for each real foo directory entry, but then filtered those names out of directory listings. Doing the same as an alternate view on snapshot space would be a simple matter of programming within ZFS, though the magic token/suffix to get you into version/snapshot space would likely not be POSIX compliant.. Ahh. I suspected it should be 'possible' to code it into ZFS. The reason it's been left to runat instead seems to be POSIX compliance then? Maybe a FS level parameter could turn that processing on or off, and even allow the admin to redefine the '@@' to anything they wish? (VMS fans might like to set it to ';' I suppose, but even then it wouldn't be the same. ;) ) -Kyle - Bill ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Cause for data corruption?
So I scrubbed the whole pool and it found a lot more corrupted files. My condolences :) General questions and comments about ZFS and data corruption: I thought RAIDZ would correct data errors automatically with the parity data. How wrong am I on that? Perhaps a parity correction was already tried, and there was too much corruption to be successful, implying a very significant amount of data corruption? Assuming the errors are being generated by bad hardware somewhere between the disk and the CPU (inclusively), how could ZFS be configured to handle these errors automatically? Set data copies to equal 2, I think. Anything else? This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Can ZFS be event-driven or not?
Kyle McDonald wrote: Bill Sommerfeld wrote: On Wed, 2008-02-27 at 13:43 -0500, Kyle McDonald wrote: How was it MVFS could do this without any changes to the shells or any other programs? I ClearCase could 'grep FOO /dir1/dir2/file@@/main/*' to see which version of 'file' added FOO. (I think @@ was the special hidden key. It might have been something else though.) When I last used clearcase (on the order of 12 years ago) foo@@/ only worked within clearcase mvfs filesystems. It behaved as if the filesystem created a foo@@ virtual directory for each real foo directory entry, but then filtered those names out of directory listings. Doing the same as an alternate view on snapshot space would be a simple matter of programming within ZFS, though the magic token/suffix to get you into version/snapshot space would likely not be POSIX compliant.. Ahh. I suspected it should be 'possible' to code it into ZFS. The reason it's been left to runat instead seems to be POSIX compliance then? Yes, we have runat for POSIX compliance. An earlier prototype of Solaris extended attributes utilized a /@/ syntax to enter enter xattr space. For example: /data/file1/@/ /data/file1/@/attr.1 ... or /data/dir1/@/ A readdir of /data/dir1 wouldn't show the @ directory, but you could always request to enter it. This violated posix in a couple of ways. One we took away the @ filename and two you can't have a directory on a file. It was a really nice model, and I still kind of wish we could have integrated it that way. -Mark ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Can ZFS be event-driven or not?
Mark Shellenbaum wrote: Kyle McDonald wrote: Bill Sommerfeld wrote: On Wed, 2008-02-27 at 13:43 -0500, Kyle McDonald wrote: How was it MVFS could do this without any changes to the shells or any other programs? I ClearCase could 'grep FOO /dir1/dir2/file@@/main/*' to see which version of 'file' added FOO. (I think @@ was the special hidden key. It might have been something else though.) When I last used clearcase (on the order of 12 years ago) foo@@/ only worked within clearcase mvfs filesystems. It behaved as if the filesystem created a foo@@ virtual directory for each real foo directory entry, but then filtered those names out of directory listings. Doing the same as an alternate view on snapshot space would be a simple matter of programming within ZFS, though the magic token/suffix to get you into version/snapshot space would likely not be POSIX compliant.. Ahh. I suspected it should be 'possible' to code it into ZFS. The reason it's been left to runat instead seems to be POSIX compliance then? Yes, we have runat for POSIX compliance. An earlier prototype of Solaris extended attributes utilized a /@/ syntax to enter enter xattr space. For example: /data/file1/@/ /data/file1/@/attr.1 ... or /data/dir1/@/ A readdir of /data/dir1 wouldn't show the @ directory, but you could always request to enter it. This violated posix in a couple of ways. One we took away the @ filename and two you can't have a directory on a file. It was a really nice model, and I still kind of wish we could have integrated it that way. Why not resurrect the behavior, but default it to off, and leave it to the user to enable with a ZFS filesystem or pool attribute? -Kyle -Mark ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Can ZFS be event-driven or not?
Bill Sommerfeld wrote: Doing the same as an alternate view on snapshot space would be a simple matter of programming within ZFS, though the magic token/suffix to get you into version/snapshot space would likely not be POSIX compliant.. We already have a POSIX compliant file system for ZFS, implemented by the ZFS POSIX Layer (ZPL). We also have ZVols which don't use the ZPL. Perhaps some enterprising soul could add another file system type to ZFS :-) Step right up! Invent something cool! Be the life of the party! Amaze your friends! -- richard ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Can ZFS be event-driven or not?
Bob Friesenhahn wrote: Is it possible to create a ZFS pool using a backing file created in xattr space? Why would you want to do that ? I tried but could get it to work with the CLI. However it may be possible via the (private) libzfs function call interface. da64-x4500b-gmp03# cd /tmp da64-x4500b-gmp03# runat da64-x4500b-gmp03# touch silly da64-x4500b-gmp03# runat silly mkfile 64m pool_file_1 da64-x4500b-gmp03# runat silly zpool create silly `pwd`/pool_file_1 cannot open '/tmp/pool_file_1': No such file or directory Which is correct because it isn't in /tmp -- Darren J Moffat ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
[zfs-discuss] Does a mirror increase read performance
Quick question: If I create a ZFS mirrored pool, will the read performance get a boost? In other words, will the data/parity be read round robin between the disks, or do both mirrored sets of data and parity get read off of both disks? The latter case would have a CPU expense, so I would think you would see a slow down. Thanks, Jon ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS vs. Novell NSS
On 2/28/08, Alan Perry [EMAIL PROTECTED] wrote: Tim wrote: Don't forget, ZFS is open source, and can be ported to any other number of platforms as well. It's also currently supported on FreeBSD 7.0, and is basically production ready on that platform. The open source is HUGE in my mind, you aren't tied to Solaris. Granted, that is where the main development is taking place right now, but if Sun were to fold up shop, or kill off solaris *cough*netware*cough*, zfs isn't going anywhere, and your data should be portable. I'm going to be blunt, and probably will rile up a few trolls if there are any on this mailing list: If you're talking to anyone still on netware, they're a netware zealot, and nothing you can say is going to change that. If they haven't found a reason to throw netware under the bus yet, they aren't going to. No reasonable argument as to why ZFS is superior to NSS will be heard, there will always be some caveat (ITS NOT SUPPORTED BY NOVELL!!!11), as to why it's just not a good enough reason to switch. Out of the Novell-types at the talk, one was a Novell zealot and the rest were just folks who make a living supporting Novell customers. Also, NSS was apparently been ported to Linux. alan ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Does a mirror increase read performance
Jonathan Loran writes: Quick question: If I create a ZFS mirrored pool, will the read performance get a boost? Yes. I use a stripe of mirrors to get better read and write performance. Ian. ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Does a mirror increase read performance
Le 28 févr. 08 à 20:14, Jonathan Loran a écrit : Quick question: If I create a ZFS mirrored pool, will the read performance get a boost? In other words, will the data/parity be read round robin between the disks, or do both mirrored sets of data and parity get read off of both disks? The latter case would have a CPU expense, so I would think you would see a slow down. 2 disks mirrored together can read data faster than a single disk. So to service a read only one side of the mirror is read. Raid-Z parity is only read in the presence of checksum errors. Thanks, Jon ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Does a mirror increase read performance
Roch Bourbonnais wrote: Le 28 févr. 08 à 20:14, Jonathan Loran a écrit : Quick question: If I create a ZFS mirrored pool, will the read performance get a boost? In other words, will the data/parity be read round robin between the disks, or do both mirrored sets of data and parity get read off of both disks? The latter case would have a CPU expense, so I would think you would see a slow down. 2 disks mirrored together can read data faster than a single disk. So to service a read only one side of the mirror is read. Raid-Z parity is only read in the presence of checksum errors. That's what I suspected, but I'm glad to get the final word on this. BTW, I guess I should have said checksums instead of parity. My bad. Thanks, Jon ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS vs. Novell NSS
On 2/28/08, Alan Perry [EMAIL PROTECTED] wrote: Tim wrote: Don't forget, ZFS is open source, and can be ported to any other number of platforms as well. It's also currently supported on FreeBSD 7.0, and is basically production ready on that platform. The open source is HUGE in my mind, you aren't tied to Solaris. Granted, that is where the main development is taking place right now, but if Sun were to fold up shop, or kill off solaris *cough*netware*cough*, zfs isn't going anywhere, and your data should be portable. I'm going to be blunt, and probably will rile up a few trolls if there are any on this mailing list: If you're talking to anyone still on netware, they're a netware zealot, and nothing you can say is going to change that. If they haven't found a reason to throw netware under the bus yet, they aren't going to. No reasonable argument as to why ZFS is superior to NSS will be heard, there will always be some caveat (ITS NOT SUPPORTED BY NOVELL!!!11), as to why it's just not a good enough reason to switch. Out of the Novell-types at the talk, one was a Novell zealot and the rest were just folks who make a living supporting Novell customers. Also, NSS was apparently been ported to Linux. alan Glad to hear that. I've NEVER understood people being close minded about technology. My experiences have been less than stellar with Netware folks. My belief has always been the sooner you realize technology is a tool and to use it as such, the sooner you will learn to use it efficiently. The greatest hammer in the world will be inferior to a drill when driving a screw :) ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Does a mirror increase read performance
Le 28 févr. 08 à 21:00, Jonathan Loran a écrit : Roch Bourbonnais wrote: Le 28 févr. 08 à 20:14, Jonathan Loran a écrit : Quick question: If I create a ZFS mirrored pool, will the read performance get a boost? In other words, will the data/parity be read round robin between the disks, or do both mirrored sets of data and parity get read off of both disks? The latter case would have a CPU expense, so I would think you would see a slow down. 2 disks mirrored together can read data faster than a single disk. So to service a read only one side of the mirror is read. Raid-Z parity is only read in the presence of checksum errors. That's what I suspected, but I'm glad to get the final word on this. BTW, I guess I should have said checksums instead of parity. My bad. OK. The checksum is a different story and is stored within the metadata block pointing to the data block. So given that to reach the data block we've already had to read the metadata block, checskum validation is never the source of an I/O. Thanks, Jon ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Does a mirror increase read performance
Roch Bourbonnais wrote: Le 28 févr. 08 à 21:00, Jonathan Loran a écrit : Roch Bourbonnais wrote: Le 28 févr. 08 à 20:14, Jonathan Loran a écrit : Quick question: If I create a ZFS mirrored pool, will the read performance get a boost? In other words, will the data/parity be read round robin between the disks, or do both mirrored sets of data and parity get read off of both disks? The latter case would have a CPU expense, so I would think you would see a slow down. 2 disks mirrored together can read data faster than a single disk. So to service a read only one side of the mirror is read. Raid-Z parity is only read in the presence of checksum errors. That's what I suspected, but I'm glad to get the final word on this. BTW, I guess I should have said checksums instead of parity. My bad. OK. The checksum is a different story and is stored within the metadata block pointing to the data block. So given that to reach the data block we've already had to read the metadata block, checskum validation is never the source of an I/O. I really need to read those ZFS internals docs (in all my spare time ;) Thanks, Jon ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS vs. Novell NSS
Tim wrote: The greatest hammer in the world will be inferior to a drill when driving a screw :) The greatest hammer in the world is a rotary hammer, and it works quite well for driving screws or digging through degenerate granite ;-) Need a better analogy. Here's what I use (quite often) on the ranch: http://www.hitachi-koki.com/powertools/products/hammer/dh40mr/dh40mr.html -- richard ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS vs. Novell NSS
Richard Elling [EMAIL PROTECTED] writes: Tim wrote: The greatest hammer in the world will be inferior to a drill when driving a screw :) The greatest hammer in the world is a rotary hammer, and it works quite well for driving screws or digging through degenerate granite ;-) Need a better analogy. Here's what I use (quite often) on the ranch: http://www.hitachi-koki.com/powertools/products/hammer/dh40mr/dh40mr.html Hasn't the greatest hammer in the world lost the ability to drive nails? I'll have to start belting them in with the handle of a screwdriver... ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS vs. Novell NSS
Hm - Based on this detail from the page: Change lever for switching between Rotation + Hammering , Neutral and Hammering only I'd hope it could still hammer... Though I'd suspect the size of nails it would hammer would be somewhat limited... ;) Nathan. Boyd Adamson wrote: Richard Elling [EMAIL PROTECTED] writes: Tim wrote: The greatest hammer in the world will be inferior to a drill when driving a screw :) The greatest hammer in the world is a rotary hammer, and it works quite well for driving screws or digging through degenerate granite ;-) Need a better analogy. Here's what I use (quite often) on the ranch: http://www.hitachi-koki.com/powertools/products/hammer/dh40mr/dh40mr.html Hasn't the greatest hammer in the world lost the ability to drive nails? I'll have to start belting them in with the handle of a screwdriver... ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Permanently removing vdevs from a pool
I found this feature to be incredibly useful when managing a Digital Unix system with AdsFS. Migrating to a larger disk (or larger hardware RAID set) was a simple add, remove and wait for the filesystem to clean up. This was done with multiple users online. Good Stuff ! Keep up the good work ! This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] ZFS vs. Novell NSS
Boyd Adamson wrote: Richard Elling [EMAIL PROTECTED] writes: Tim wrote: The greatest hammer in the world will be inferior to a drill when driving a screw :) The greatest hammer in the world is a rotary hammer, and it works quite well for driving screws or digging through degenerate granite ;-) Need a better analogy. Here's what I use (quite often) on the ranch: http://www.hitachi-koki.com/powertools/products/hammer/dh40mr/dh40mr.html Hasn't the greatest hammer in the world lost the ability to drive nails? I use guns to drive nails :-) Maybe you guys have been so busy playing with computers that you've missed a complete revolution in the productivity tools for construction? If you want, I'm giving free fence building lessons next week, you can catch up on all of the latest technology :-) -- richard ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] nfs over zfs
[EMAIL PROTECTED] said: i am a little new to zfs so please excuse my ignorance. i have a poweredge 2950 running Nevada B82 with an Apple Xraid attached over a fiber hba. they are formatted to JBOD with the pool configured as follows: . . . i have a filesystem (tpool4/seplog) shared over nfs. creating files locally seems to be fine but writing files over nfs seem to be extremely slow on one of the clients(os x) it reports over 3hours to copy a 500MB file. also during the copy when i issue a zpool iostat -v 5 the response time increases for the command. i have also noticed that none of the led's on the drives flicker. If you haven't already, tell the Xraid to ignore cache-flush requests from the host: http://www.opensolaris.org/jive/thread.jspa?threadID=11641 Regards, Marion ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] path-name encodings
OK, thanks. I still haven't got any answer to my original question, though. I.e., is there some way to know what text the filename is, or do I have to make a more or less wild guess what encoding the program that created the file used? You have to guess. As far as I know, Apple's HFS (and HFS+) is the only file system which stores the encoding along with the filename. NFS doesn't provide a mechanism to send the encoding with the filename; I don't believe that CIFS does, either. If you're writing the application, you could store the encoding as an extended attribute of the file. This would be useful, for instance, for an AFP server. The trick is that in order to support such things as casesensitivity=false for CIFS, the OS needs to know what characters are uppercase vs lowercase, which means it needs to know about encodings, and reject codepoints which cannot be classified as uppercase vs lowercase. I don't see why the OS would care about that. Isn't that the job of the CIFS daemon? The CIFS daemon can do it, but it would require that the daemon cache the whole directory in memory (at least, to get reasonable efficiency). This doesn't work so well for large directories. If you leave it up to the CIFS daemon, you also wind up with problems if you have a single sharepoint shared between local users, NFS CIFS -- the NFS client can create two files named a and A, but the CIFS client can only see one of those. As a matter of fact I don't see why the OS would need to know how to decode any filename-bytes to text. However, I firmly believe that user applications should have that opportunity. If the encoding of filenames is not known (explicitly or implicitly) then applications don't have that opportunity. Yes -- that's why Apple includes an encoding byte in both HFS and HFS+. (In HFS+, filenames are normalized to 16-bit Unicode, but the encoding is still useful in choosing how to recompose the characters, and in providing hints for applications which prefer the names in some 8-bit encoding.) -- Anton This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
Re: [zfs-discuss] Cause for data corruption?
Thanks for your reassuring post, loomy :) I'm pretty sure the reason for all this is some bad hardware.. But I can't get VTS to work, looks like its not supported for this kind of hardware. And in order to run some other stresstest software or something I would have to connect monitor, keyboard and dvd rom.. which I'm just so sick of doing :) Hopefully I can motivate myself on the weekend .. I'll keep you all here updated when I find something. This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
