Re: moving from raw chunks to cooked files
Oh, Forgot to mention something. You can't just change the ROOTPATH in the onconfig file and expect it to work. When the engine starts up, it reads only the reserved pages from the file pointed to by ROOTPATH to find the chunk table, once it does that the engine closes ROOTPATH and opens all of the chunks using the paths stored in the chunk table it found in ROOTPATH, including the initial rootdb dbspace chunk. In theory, you could have ROOTPATH set to a small file that just has a copy of the reserved pages from the real root chunk and as long as the path for chunk #1 that's recorded there is a valid root chunk it would work. Nasty thing to try, but I have seen how this works when I've renamed or moved chunks and forgotten to update the ONCONFIG file. Art Art S. Kagel Advanced DataTools (www.advancedatatools.com) IIUG Board of Directors (art@iiug.org) Disclaimer: Please keep in mind that my own opinions are my own opinions and do not reflect on my employer, Advanced DataTools, 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 Wed, Aug 25, 2010 at 12:17 PM, Aleksander Kamenik < aleksander@krediidiinfo.ee> wrote: > > Yeah, Linus has been trying to get rid of RAW files for many years. I > > wish he'd just give it up. Anyway, there is no problem using cooked > > files, and migrating the data is as simple as dd'ing the data from the > > RAW devices to new filesystem files and then relinking the link paths > > that IDS using to access the RAW devices to the filesystem files. > > This would create 2 files instead of 2 raw devices. Any way to split the > raw device into separate files where each file would corresponding to a > chunk? I think it might be possible using dd's skip and count options. > > How I can I change paths in Informix? root dbs is specified in the onconfig > file and that's in one chunk fortunately, but I don't know how to change the > paths for all the other chunks. I also don't know what you mean by > relinking. > > > You > > should use the simplest filesystem available, no journalled filesystems > > like EXT3 and EXT4. I would suggest just using an old EXT2 filesystem > > as the best choice. It's very low overhead compared to the more modern > > filesystems. > > Makes sense, thanks. > > > Another option, BTW, would be to use COOKED (aka block) devices rather > > than filesystem files. COOKED devices tend to be a little faster than > > filesystem files even with DIRECT_IO enabled on both. > > What do you mean by that; that each chunk or set of chunks would have their > own partition on disk? So instead on /dev/raw/raw1 I'd have /dev/sda1 for > example? > > > > > Aleksander Kamenik > System Administrator > Krediidiinfo AS > an Experian Company > Phone: +372 665 9649 > Email: aleksander@krediidiinfo.ee > > http://www.krediidiinfo.ee/ > http://www.experiangroup.com/ > > > > > Art > > > > Art S. Kagel > > Advanced DataTools (www.advancedatatools.com) > > IIUG Board of Directors (art@iiug.org) > > > > Disclaimer: Please keep in mind that my own opinions are my own > > opinions and do not reflect on my employer, Advanced DataTools, 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 Wed, Aug 25, 2010 at 10:43 AM, Aleksander Kamenik > > <aleksander@krediidiinfo.ee> wrote: > > > > > > Hi, > > > > We're running Suse Linux Enterprise Server on x86 and with the > > latest SLES11SP1 release notes comes this announcement: > > > > "The RAW devices are deprecated and will be removed with one of > > the next Service Packs or SUSE Linux Enterprise Server 12." > > > > I'm about to reinstall Informix onto new drives so might as well > > migrate to cooked files. > > > > What filesystem is recommended? Are there any significant > > performance issues nowadays? > > > > Currently I have two raw devices which contain a total of 18 > > chunks. I would like to see them as 18 files on four different > > drives/partitions after the migration. I can't find any documentation > > on migrating to cooked files. Is this even possible? > > > > Using Informix 11.50.UC7. > > > > Regards, > > > > Aleksander Kamenik > > System Administrator > > Krediidiinfo AS > > an Experian Company > > Phone: +372 665 9649 > > Email: aleksander@krediidiinfo.ee > > > > http://www.krediidiinfo.ee/ > > http://www.experiangroup.com/ > > > > > > _______________________________________________ > > Informix-list mailing list > > Informix-list@iiug.org > > http://www.iiug.org/mailman/listinfo/informix-list > > > > > > > _______________________________________________ > Informix-list mailing list > Informix-list@iiug.org > http://www.iiug.org/mailman/listinfo/informix-list >