clarification on Informix on Suse Linux
User questioned whether Informix 12.1 on SUSE Linux 11 requires cooked filesystems only or can also use raw devices. Experts confirmed Informix supports raw, cooked, and filesystem files on any platform if the OS supports them. However, raw devices are deprecated in SUSE Linux 11 and may be discontinued. Alternatives include using LVM with O_DIRECT flag or DIRECT_IO on cooked files for similar performance without raw device complexity.
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Our ERP is forcing us to move from HPUX to Suse Linux and they said something I'm not sure Is 100% correct. They have said that Informix 12.1 on Suse Linux can only be installed using cooked file system I do not think this is 100% correct, more likely they only wish to support cooked file system. And since they recommend using virtual servers, coked file systems make cloning easy, but raw LUNs have to be detached for the cloning to be done. Am I correct that Informix 12.1 FC6 on Suse Linux 11 can handle raw or cooked file systems? The choice of which to use is the installer? I couldn't find anything in the documentation saying only cooked file system, but maybe I was looking at the wrong documents. John David Adamski, Sr. Network Specialist Graceland University, 1 Univeristy Place, Lamoni, IA 50140 adamski@graceland.edu 641-784-5267
Linus has deprecated raw disk - I think the most recent releases of Linux have stopped supporting it altogether. Its probably best to start going to the brave new world when you make the change. :-( PS For Gods sake, do NOT use a journaled file system for your dbspace chunks. > On 9 Feb 2017, at 17:39, John Adamski (Work Account) <adamski@graceland.edu> wrote: > > Our ERP is forcing us to move from HPUX to Suse Linux and they said something > I'm not sure Is 100% correct. > > They have said that Informix 12.1 on Suse Linux can only be installed using > cooked file system I do not think this is 100% correct, more likely they only > wish to support cooked file system. And since they recommend using virtual > servers, coked file systems make cloning easy, but raw LUNs have to be > detached for the cloning to be done. > > Am I correct that Informix 12.1 FC6 on Suse Linux 11 can handle raw or cooked > file systems? The choice of which to use is the installer? I couldn't find > anything in the documentation saying only cooked file system, but maybe I was > looking at the wrong documents. > > John David Adamski, Sr. Network Specialist > Graceland University, 1 Univeristy Place, Lamoni, IA 50140 > adamski@graceland.edu > 641-784-5267 > > > ******************************************************************************* > Forum Note: Use "Reply" to post a response in the discussion forum. >
John: This is not a problem. Informix on ANY platform can use RAW devices, cooked devices, or filesystem files for chunks. Some Linux distributions have historically dropped support for raw devices from one release to another and often reinstated it for the following release. Linus is opposed to raw, but it still lives on. The Informix installation does not specify or care whether raw is supported. If a raw device is available on the platform you can define a chunk against it. Period. Art Art S. Kagel, President and Principal Consultant ASK Database Management www.askdbmgt.com Blog: http://informix-myview.blogspot.com/ Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on the IIUG, nor any other organization with which I am associated either explicitly, implicitly, or by inference. Neither do those opinions reflect those of other individuals affiliated with any entity with which I am affiliated nor those of the entities themselves. On Thu, Feb 9, 2017 at 12:39 PM, John Adamski (Work Account) < adamski@graceland.edu> wrote: > Our ERP is forcing us to move from HPUX to Suse Linux and they said > something > I'm not sure Is 100% correct. > > They have said that Informix 12.1 on Suse Linux can only be installed using > cooked file system I do not think this is 100% correct, more likely they > only > wish to support cooked file system. And since they recommend using virtual > servers, coked file systems make cloning easy, but raw LUNs have to be > detached for the cloning to be done. > > Am I correct that Informix 12.1 FC6 on Suse Linux 11 can handle raw or > cooked > file systems? The choice of which to use is the installer? I couldn't find > anything in the documentation saying only cooked file system, but maybe I > was > looking at the wrong documents. > > John David Adamski, Sr. Network Specialist > Graceland University, 1 Univeristy Place, Lamoni, IA 50140 > adamski@graceland.edu > 641-784-5267 > > > ************************************************************ > ******************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > --94eb2c0d44c28bb4b405481cdcea
Informix ======== https://www.ibm.com/support/knowledgecenter/en/SSGU8G_12.1.0/com.ibm.relnotes.do c/notes/ifx_1210xc6/mach/ids_machine_notes_12.10.lin64.html "14. Raw Character Devices Some Linux distributions support binding a raw character device to a block device. Any block device may be used. IBM Informix Database Server supports using raw character devices." So I would say it depends if the Linux version supports raw devices. Suse Linux 11 ============= ftp://ftp.uni-halle.de/suse/SLES.11/SLES11-SP4/docu/RELEASE-NOTES.en.html "11.6. Packages and Features to Be Removed in the Future ... The raw block devices (major 162) are deprecated and will be discontinued with one of the next Service Packs or SUSE Linux Enterprise Server 12" So on SUSE Linux raw devices are deprecated and MAY be discontinued on the next Service Pack. Regards, David. > On 09 February 2017 at 18:08 Art Kagel <art.kagel@gmail.com> wrote: > > > John: > > This is not a problem. Informix on ANY platform can use RAW devices, cooked > devices, or filesystem files for chunks. Some Linux distributions have > historically dropped support for raw devices from one release to another > and often reinstated it for the following release. Linus is opposed to raw, > but it still lives on. The Informix installation does not specify or care > whether raw is supported. If a raw device is available on the platform you > can define a chunk against it. Period. > > Art > > Art S. Kagel, President and Principal Consultant > ASK Database Management > www.askdbmgt.com > > Blog: http://informix-myview.blogspot.com/ > > Disclaimer: Please keep in mind that my own opinions are my own opinions > and do not reflect on the IIUG, nor any other organization with which I am > associated either explicitly, implicitly, or by inference. Neither do > those opinions reflect those of other individuals affiliated with any > entity with which I am affiliated nor those of the entities themselves. > > On Thu, Feb 9, 2017 at 12:39 PM, John Adamski (Work Account) < > adamski@graceland.edu> wrote: > > > Our ERP is forcing us to move from HPUX to Suse Linux and they said > > something > > I'm not sure Is 100% correct. > > > > They have said that Informix 12.1 on Suse Linux can only be installed using > > cooked file system I do not think this is 100% correct, more likely they > > only > > wish to support cooked file system. And since they recommend using virtual > > servers, coked file systems make cloning easy, but raw LUNs have to be > > detached for the cloning to be done. > > > > Am I correct that Informix 12.1 FC6 on Suse Linux 11 can handle raw or > > cooked > > file systems? The choice of which to use is the installer? I couldn't find > > anything in the documentation saying only cooked file system, but maybe I > > was > > looking at the wrong documents. > > > > John David Adamski, Sr. Network Specialist > > Graceland University, 1 Univeristy Place, Lamoni, IA 50140 > > adamski@graceland.edu > > 641-784-5267 > > > > > > ************************************************************ > > ******************* > > Forum Note: Use "Reply" to post a response in the discussion forum. > > > > > > --94eb2c0d44c28bb4b405481cdcea > > > ******************************************************************************* > > Forum Note: Use "Reply" to post a response in the discussion forum. >
RAW devices on Linux have always been tricky.... coming and going, Linus fighting them etc. But this misses the point. RAW devices were used to avoid system memory caching and avoid context switching (user vs kernel mode) And since version 10 (with intermittent issues) we've been supporting block devices opened with O_DIRECT flag. This translates to that you can create your "pseudo-raw" block devices with LVM and use them with Informix as you would do with RAW devices. You'll get KAIO... no buffer caching and no context switch on IO. And then again, we're possibly still missing the point... You can get this with cooked files which are much easier to manage, don't require root intervention etc... That's because we support DIRECT I/O (DIO) through the ONCONFIG parameter DIRECT_IO. So... you could do some tests.... But I doubt that a well done test will show significant differences... If you really enjoy creating the "raw" devices... do it with LVM and don't bother with the block/character interface. We'll open them with O_DIRECT. On the other hand, why not try the filesystem approach which make it more easy and manageable? Regards. On Thu, Feb 9, 2017 at 5:39 PM, John Adamski (Work Account) < adamski@graceland.edu> wrote: > Our ERP is forcing us to move from HPUX to Suse Linux and they said > something > I'm not sure Is 100% correct. > > They have said that Informix 12.1 on Suse Linux can only be installed using > cooked file system I do not think this is 100% correct, more likely they > only > wish to support cooked file system. And since they recommend using virtual > servers, coked file systems make cloning easy, but raw LUNs have to be > detached for the cloning to be done. > > Am I correct that Informix 12.1 FC6 on Suse Linux 11 can handle raw or > cooked > file systems? The choice of which to use is the installer? I couldn't find > anything in the documentation saying only cooked file system, but maybe I > was > looking at the wrong documents. > > John David Adamski, Sr. Network Specialist > Graceland University, 1 Univeristy Place, Lamoni, IA 50140 > adamski@graceland.edu > 641-784-5267 > > > ************************************************************ > ******************* > Forum Note: Use "Reply" to post a response in the discussion forum. > > -- Fernando Nunes Portugal http://informix-technology.blogspot.com My email works... but I don't check it frequently... --001a11475394a4feb80548243aa5
In my case I had to do raw devices because the only way they found they could cheaply do a shared disk was with raw devices. And they wanted an SDS. Still doing test but everything seems to be working ok... yet I feel I'll miss the easy cooked files management.