Re: Raw VS. Cooked

Sigh, You're not. You're using the LVM. You're creating a filesystem but not mounting it. You then create symbolic links to these defined file systems. So instead of raw disk, you have *raw* LVM partitions. Just leave an offset of 1 or 2 pages at the front for control information. Hint: what's the largest Disk available. What's the largest dbspace you can create? -Uncle Mikey Helmut Leininger wrote: > Sorry, I still don't see the reason for using a file system for a raw Informix > chunk. > > Michael Segel wrote: > > > Actually there are several reasons. > > > > 1) Disk size. > > Whats the limit on a raw partition within Informix? > > Whats currently the largest disk you can buy? > > > > Actually the max. raw partition size (or better chunk size + offset) for > Informix is 2GB. And that's the same for a "cooked" chunk. So, it does not make > sense to have a logical volume (with or without a filesystem - and a filesystem > always resides in a logical volume) larger than 2 GB if it should contain an > Informix chunk. Whatever the disk size may be. You may use it by allocating > enough logical volumes (there is no practical limit on the number of logical > volumes) > > > 2) Mirroring. > > You can use Informix, > > You can use the OS > > > > You can use the same with "raw" logical volumes. Either Informix or AIX. Note > that AIX-Mirroring (up to 2 additional copies) is on logical volume level and > not on file system level. > > > 3) Striping. > > You can have the same logical volume accross multiple > > disks within the logical volume. Granted if a disk > > fails, recovery and rebuilding is more difficult. > > > > That's not restricted to file systems. > > > 4) Management. > > You can now cross utilize your disk spaces. > > Inner blocks DB, outer blocks file systems. > > > > Ok. You specify these attributes for a logical volume, not for a file system. > > > Now, > > You say that *someone* may mount the filesystem and destroy > > your data? > > Whats to stop some eager admin doing that if it is a raw > > partition? > > > > True. But if there is no filesystem on the logical volume, it's more difficult. > You cannot say a "mount all". > > > The bottom line, you the DBA and the Sys Admin need to work in > > sync, especially if you are the same person. (Multiple > > personalities can be a real problem ;-) > > > > -Just a simple *free* tip from your uncle mikey. > > > > Helmut Leininger wrote: > > > > > > > > I would *not* do that. It is too dangerous. Somebody might mount the > > > filesystem use it and such destroy your database !!!And there is no reason > > > to do that. > > > > > [SNIP] > > -- > > #include <std_disclaimer.h> /* Mike Segel (MS385) */ > > #include <No_Spam.h> > > #ifdef OFFENDED_BY_CONTENT > > The author takes no responsibility for this post. > > Any resemblence to a coherent rational thought is purely coincidence. > > -The Management. > > #endif > > ***************************** > > * Attention * > > -*- Due to AGIS's Refusal to Act Responsibly > > -*- Due to ACSI's Refusal to Act Responsibly > > > > We are blocking all of their domains at the packet level. > > This block will exist until they modify their policies to > > conform to existing RFCs and net community standards. > > > > We encourage all ISPs and domain holders to do the same. > > *****************************