Request: Generate zsync error recovery files for any/all Quartus 11 release files

Hello,

I'm trying to download Quartus 11, and have encountered a md5sum mismatch (relative to the listed value on the Altera web site) for the downloaded file despite using a download manager and having apparently 'successfully' downloaded the file of the expected size and name. This has happened occasionally particularly with large multi-gigabyte files which are extremely slow and unreliable to transfer with my particular internet connection situation. It is frustrating to have to start downloading over from zero having a downloaded file which is almost certainly 99.99999% correct but apparently with small pieces of corruption of unknown sizes/locations within the received files. Obviously I'd like to improve my ISP connection and isolate the cause of this corruption (it is possibly a fault in the remote server or download manager software, or possibly some ISP or OS/SW related problem), but for the moment I'd just like an easy way to recover from detected errors in downloaded files that may take several real time days to attempt to re-download (with a not so good probability of success at that...).

It is common practice in many large software/data distributions to generate some kind of ECC or block level HASH / checksum files to accompany large files such that any missing/corrupt pieces can efficiently be identified and corrected with only a small incremental download of the bad blocks. 'par' parity files, zsync, jigdo, rsync, torrent files, and other such commonly used systems enable this efficient error detection / correction functionality.

Particularly, it would be a trivial thing to use the 'zsync' program (commonly available for UNIX/LINUX) to generate a small (few megabytes) hash file that contains sufficient block level error detection data to facilitate recovery of corrupted transfers. This auxiliary file is calculated operating on any chosen known good original large file (e.g. a quartus distribution file or disc image).

Here's a working shell command line example how one might generate a "zsync" hash file based on a local copy of a particular distribution file:

zsyncmake -v -e -C 11.0_acds_web_edition.iso

That operates on the master file named 11.0_acds_web_edition.iso, and generates the file:

11.0_acds_web_edition.iso.zsync which is a few megabytes in size, and contains the relevant

error detection data allowing for incremental downloading of any problematic parts given that the

.zsync file generated is shared with anyone that may have a need to do such corrections.

Typically a software vendor would gebnerate the zsync files based on each of the large released files, and make these .zsync files also available for download in the software distribution, though anyone having

a good copy of a released file could independently generate and share this hash data for the benefit of

others.

Ideally Altera's release process could eventually be modified to automatically generate and distribute these or similar kinds of files; sharing the md5sum as is currently done is great to enable people to see if they have a corruption problem, but if they do, there's no efficient way to FIX it without such additional data as are here proposed.

Anyway I've seen some comments about people getting Quartus 11 et. al. working under UBUNTU or similar UNIX OSs, so perhaps someone who has some of these files already successfully downloaded and a UNIX workstation might consider making a zsync file out of whatever version (they're all 2+ GBy) of source files you happen to have downloaded, and share the zsync file(s) via something like an "shared material" alteraforum attachment or via some file hosting service (windows live skydrive, mediafire, rapidshare, whatever?

Or if someone on the ALTERA LAN wants to add this as a convenience to your users, it should only take a few minutes to generate them with something like:

mkdir zsync_files && cd zsync_files && find /path_to_master_release_files/ -type f -print0 | xargs -0 -n1 zsyncmake -v -e -C

cp -p *.zsync /path/to/shared/files/on/public/server/

...or otherwise upload/share the .zsync files.

(and, yes, I know, one may request the DVD, though in this case it seems that it'll take around a month to be available, hence I thought I'd ask to see if someone wanted to make the correction files available sooner...)

q.v. url for more info on zsync:

zsync.moria.org.uk/

Thanks in advance!