How do you create raw chunks on LINUX?
I created 3 partitions, named sda1, 2 and 3 - and did not create any file systems in them. When assigning chunks to INFORMIX, do I use the device names of /dev/sda1 or do I have to do something else. sda1 is a blocked device, and I thought it wants a character special device. Can anyone step me through this please? Thanks! Steve Weiland steve@internet-stuff.com
Steve Weiland wrote: > I created 3 partitions, named sda1, 2 and 3 - and did not create any file > systems in them. When assigning chunks to INFORMIX, do I use the device > names of /dev/sda1 or do I have to do something else. sda1 is a blocked > device, and I thought it wants a character special device. Can anyone step > me through this please? Thanks! As Chuck Renaud said, raw disks, meaning character-mode disk devices, are not supported by the standard Linux kernel yet -- they will be in kernel 2.4 when it is released later this year. In the interim, you can use the block devices /dev/sda[123] instead of specifying a cooked file. The software will use them correctly. On Linux 2.2 and earlier, there is no extra penalty of going through the kernel disk cache (the operations always go through the cache), whereas on Unix systems, using a block device also means using the kernel disk cache, but using a character device avoids the extra overhead of copying the data (and ensuring that the block can be written to the cache). -- Jonathan Leffler (jleffler@informix.com, jleffler@earthlink.net) Guardian of DBD::Informix v0.95 -- see http://www.perl.com/CPAN #include <disclaimer.h>
"Jonathan Leffler" <jleffler@earthlink.net> a 'crit dans le message news: 38C2DBBD.BAB27F7E@earthlink.net... > Steve Weiland wrote: > > > I created 3 partitions, named sda1, 2 and 3 - and did not create any file > > systems in them. When assigning chunks to INFORMIX, do I use the device > > names of /dev/sda1 or do I have to do something else. sda1 is a blocked > > device, and I thought it wants a character special device. Can anyone step > > me through this please? Thanks! > > As Chuck Renaud said, raw disks, meaning character-mode disk devices, > are not supported by the standard Linux kernel yet -- they will be in > kernel 2.4 when it is released later this year. I am new in Informix on Linux but when I installed my Informix on a Redhat 6.0, I created a partition with the type "empty"... Informix has could write without problem on it...I also could create few dbspaces.. My informix is a 7.30.UC10-1. Have you an explanation ? Thanx, Jean-Brice Albertus
Jean-Brice Albertus wrote: > "Jonathan Leffler" <jleffler@earthlink.net> a écrit dans le message news: > 38C2DBBD.BAB27F7E@earthlink.net... > > Steve Weiland wrote: > > > > > I created 3 partitions, named sda1, 2 and 3 - and did not create any > file > > > systems in them. When assigning chunks to INFORMIX, do I use the device > > > names of /dev/sda1 or do I have to do something else. sda1 is a blocked > > > device, and I thought it wants a character special device. Can anyone > step > > > me through this please? Thanks! > > > > As Chuck Renaud said, raw disks, meaning character-mode disk devices, > > are not supported by the standard Linux kernel yet -- they will be in > > kernel 2.4 when it is released later this year. > > I am new in Informix on Linux but when I installed my Informix on a Redhat > 6.0, I created a partition with the type "empty"... > Informix has could write without problem on it...I also could create few > dbspaces.. > > My informix is a 7.30.UC10-1. > > Have you an explanation ? I think the rest of my message gave the explanation. What you are using is a block special device, and as I said, those can be used OK. A raw device has a specific meaning -- a character special device. Further, on Unix, a raw device deliberately avoids using the kernel buffer cache, which improves performance when the DBMS handles the caching in shared memory. -- Jonathan Leffler (jleffler@informix.com, jleffler@earthlink.net) Guardian of DBD::Informix v0.95 -- see http://www.perl.com/CPAN #include <disclaimer.h>