Subject: Re: Aliases: Are alternate filesystems worth trying?

From: "Richard Goldman" <[email-masked]>
Date: Wed, 6 Jun 2001 14:36:26 -0400

Thank you all so much for the explanations and leads on understanding the issue of aliases/DID's/files/etc.

A few notes so far:

Linux Kernel-2.4.5-XFS appears to be a stable platform for netatalk.  Download the full source tree from SGI's CVS (this will ensure that you're getting the 2.4.5 kernel).  Know that this pre-patched XFS-cabable kernel distrib from SGI is missing two key files from linux/drivers/scsi/aic7xxx (Adaptec driver).  These files are aic7xxx_reg.h and aic7xxx_seq.h.  Find these files from the kernel.org distrib of the stock 2.4.5 -- and only this version, as the Adaptec driver underwent a major patch between the 2..4.4 and 2.4.5 kernels.

Remember to compile the utilities as well, and lower your alias/DID problems by lowering your inode count on XFS by creating the filesystem with this command:  mkfs.xfs -i -size=2048 /dev/whatever.  The the -size subdirective is really asking for a ratio of inodes to to fs blocks.  With Linux XFS frozen at 4k blocks, by asking for 2048 bytes here, your telling the system to be made with roughly 2 inodes per block instead of the built-in default of -size=256 giving you 16 inodes per 4k block.  That would quickly bust the 16,777,216 inode limit addressable in the 24 inode-dedicated bits in the current alias mapping scheme (which you get when you don't invoke --enable-lastdid in ./configure).

I noticed in the CVS this morning that Jeff had added the new configure option on --with-did={last,mtab).  The mtab option points to an implementation of Bob Rogers scheme to devote more of the alias address space to inodes (raised to 28 bits?  29 bits? from the current 24).

Does anyone know if the implementation is complete, i.e. that the new afpd.mtab file is being read, and this new dev-inode scheme is active and usable if --with-did=mtab is specified?

Regards,
Richard