James C. McPherson wrote: > can you guess? wrote: > ... > >> Ah - thanks to both of you. My own knowledge of video format internals >> is so limited that I assumed most people here would be at least equally >> familiar with the notion that a flipped bit or two in a video would >> hardly qualify as any kind of disaster (or often even as being >> noticeable, unless one were searching for it, in the case of >> commercial-quality video). >> >> David's comment about jpeg corruption would be more worrisome if it were >> clear that any significant number of 'consumers' (the immediate subject >> of my original comment in this area) had anything approaching 1 TB of >> jpegs on their systems (which at an average of 1 MB per jpeg would be >> around a million pictures...). If you include 'image files of various >> sorts', as he did (though this also raises the question of whether we're >> still talking about 'consumers'), then you also have to specify exactly >> how damaging single-bit errors are to those various 'sorts' (one might >> guess not very for the uncompressed formats that might well be taking up >> most of the space). And since the CERN study seems to suggest that the >> vast majority of errors likely to be encountered at this level of >> incidence (and which could be caught by ZFS) are *detectable* errors, >> they'll (in the unlikely event that you encounter them at all) typically >> only result in requiring use of a RAID (or backup) copy (surely one >> wouldn't be entrusting data of any real value to a single disk). >> > > > I have to comment here. As a bloke with a bit of a photography > habit - I have a 10Mpx camera and I shoot in RAW mode - it is > very, very easy to acquire 1Tb of image files in short order. > > Each of the photos I take is between 8 and 11Mb, and if I'm > at a sporting event or I'm travelling for work or pleasure, > it is *incredibly* easy to amass several hundred Mb of photos > every single day. > > I'm by no means a professional photographer (so I'm not out > taking photos every single day), although a very close friend > of mine is. My photo storage is protected by ZFS with mirroring > and backups to dvd media. My profotog friend has 3 copies of > all her data - working set, immediate copy on usb-attached disk, > and second backup also on usb-attached disk but disconnected. > > Even if you've got your original file archived, you still need > your working copies available, and Adobe Photoshop can turn that > RAW file into a PSD of nearly 60Mb in some cases. > > It is very easy for the storage medium to acquire some degree > of corruption - whether it's a CF or SD card, they all use > FAT32. I have been in the position of losing photos due to > this. Not many - perhaps a dozen over the course of 12 months. > > That flipped bit which you seem to be dismissing as "hardly... > a disaster" can in fact make your photo file totally useless, > because not only will you probably not be able to get the file > off the media card, but whatever software you're using to keep > track of your catalog will also be unable to show you the > entire contents. That might be the image itself, or it might > be the equally important EXIF information. > > I don't depend on FAT32-formatted media cards to make my > living, fortunately, but if I did I imagine I'd probably end > up only using each card for about a month before exercising > caution and purchasing a new one rather than depending on the > card itself to be reliable any more. > > 1Tb of photos shot on a 10MPx camera in the camera's native > RAW format is around 100,000 photos. It's not difficult to > imagine a "consumer" having that sort of storage requirement. > Hi,
I have been watching the thread, having been using a digital cameras for over 8 years I have noticed that as resolution increases the file size changes accordingly. The quality of the images has improved dramatically which is why newer camera are purchased. As I also have a project to scan all my parents and grandparents old photographs to provide a record for my children my disk usage has increased dramatically. Given that I purchased a digital video camera this has further added for the need of disk space. Previously I had two 73GB disks, now I have 750GB (4 x 250GB RAID5). The problem of archival is either to copy to another computer which I currently do, or hope that HVD becomes a cheap archival method. > > > James C. McPherson > -- > Senior Kernel Software Engineer, Solaris > Sun Microsystems > http://blogs.sun.com/jmcp http://www.jmcp.homeunix.com/blog > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > > ______________________________________________________________________ > This email has been scanned by the MessageLabs Email Security System. > For more information please visit http://www.messagelabs.com/email > ______________________________________________________________________ > > -- Regards Russell Email: russell dot aspinwall at flomerics dot co dot uk Network and Systems Administrator Flomerics Ltd Telephone: 020-8941-8810 x3116 81 Bridge Road Facsimile: 020-8941-8730 Hampton Court Surrey, KT8 9HH United Kingdom _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
