FUJITA Tomonori wrote: > On Mon, 18 Aug 2008 15:47:00 +1000 > Mark Harvey <markh794 at gmail.com> wrote: > >> An alternative backing store primarily for SSC device which uses a meta-data header for each block of data. >> >> Embedded with the metadata are forward & back pointers to next & previous headers forming a double-linked list of headers. > > I think that everyone agrees on having the separate metadata. When we > discussed this last time, I thought that we use extended attributes to > store metadata. Looks like that your code uses the first bytes of a > file to store the metadata. Using extended attributes doesn't work? To be honest, I haven't looked at the extended attribute method. How much data can be saved within the extended attributes ? To support variable block, metadata needs to be kept for each block. > > >> Patch 1/2 patch includes bs_tape and a couple of helper utilities for: >> - creating 'blank' media >> - Dumping media headers >> Patch 2/2 patches the tgt-core-test script which I use to setup the VTL. >> >> Note: The bs_tape is almost at the same level of functionality as the bs_ssc without Richard Sharps recent patches. > > Almost? What are the differences? It does not respond correctly when hitting a filemark. Only a small amount of effort to bring up to equivalent functionality or more. Advantage is the easy ability to implement variable size block support. > > Well, I don't think that we need two ssc implementations. True. > We need to > integrate two. Except for the metadata handling, what are the > differences between them? True. I had it within 95+% complete when Richard submitted his set of patches. So I emailed this in as well as a comparison & comment. Cheers Mark -- To unsubscribe from this list: send the line "unsubscribe stgt" in the body of a message to majordomo at vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html |