On 4 Feb 2010, at 16:35, Bob Friesenhahn wrote: > On Thu, 4 Feb 2010, Darren J Moffat wrote: >>> Thanks - IBM basically haven't test clearcase with ZFS compression >>> therefore, they don't support currently. Future may change, as such my >>> customer cannot use compression. I have asked IBM for roadmap info to find >>> whether/when it will be supported. >> >> That is FUD generation in my opinion and being overly cautious. The whole >> point of the POSIX interfaces to a filesystem is that applications don't >> actually care how the filesystem stores their data. > > Clearcase itself implements a versioning filesystem so perhaps it is not > being overly cautious. Compression could change aspects such as how free > space is reported.
I'd also like to echo Bob's observations here. Darren's FUDFUD is based on limited experience of ClearCase, I expect ... On the client side, ClearCase actually presnets itself as a mounted filesystem, regardless of what the OS has under the covers. In other words, a ClearCase directory will never be 'ZFS' because it's not ZFS, it's ClearCaseFS. On the server side (which might be the case here) the way ClearCase works is to represent the files and contents in a way more akin to a database (e.g. Oracle) than traditional file-system approaches to data (e.g. CVS, SVN). In much the same way there are app-specific issues with ZFS (e.g. matching block-sizes, dealing with ZFS snapshots on a VM image and so forth) there may well be some with ClearCase. At the very least, though, IBM may just be unable/willing to test it at the time and put their stamp of approval on it. In many cases for IBM products, there are supported platforms (often with specific patch levels), much like there are offically supported Solaris platforms and hot-fixes to go for certain applications. They may well just being cautious in what there is until they've had time to test it out for themselves - or more likely, until the first set of paying customers wants to get invoiced for the investigation. But to claim it's FUD without any real data to back it up is just FUD^2. Alex _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
