Sure, I take the point of a 'random' dt user setting up bcache. To be fair we aeren't really talking about a random user here but someone who already uses a NAS, and an SSD 'cache' disk and is a heavy enough user to be concerned about the 1/4 second it should take to read or write a raw image to a NAS but your point is valid.
As you ask I don't have any arguments not to use a local RAW image if it is present, indeed I think this is a very good idea provided it does not require too much bloat in dt and is done properly i.e. it honours file timestamps to know which is the most up to date copy. There is a downside of course in that for each image read you need to first read the inode info on both NAS and SSD to know which image to start reading so there is extra overhead, but it should be minimal. -----Original Message----- From: Pascal Obry [mailto:pas...@obry.net] Sent: 09 April 2015 14:06 To: Rob Z. Smith Cc: Moritz Schallaböck; darktable-users Subject: Re: [Darktable-users] Copy Locally - Different use case 2015-04-09 14:44 GMT+02:00 Rob Z. Smith <rzsm...@nhbc.co.uk>: > Not that I want to discourage anyone building facilities into dt if they wish > but if there is a system problem where the NAS drive is too slow and local > SSD has to be used for speed I tend to think addressing it at the system > level rather than within the dt application is best. Personally I store my > o/s, the dt application code, home directory and dt database etc on SSD and > use a NAS to hold just the images. This architecture works well - I can read > and write raw images to the NAS at about 4 images per second even on my > pretty humble system. If it was too slow handling the images themselves I > think I would first get a better NAS and network link, and if that was still > not fast enough I might front up the NAS with SSD using bcache or similar - > that way I would get the SSD speed benefits on a NAS volume for all > applications using it not just dt. > Tell a random user of dt to setup bcache! The target for dt is photographers. And let me repeat, the patch is simple. The net effect is that dt will always use the RAW locally if possible gaining speed "for free". No setup. And there is no cons. BTW, what would be the argument to *not* use the cached RAWs when present? Also, note that some RAW are heavy and they tend to get heavier. -- Pascal Obry / Magny Les Hameaux (78) The best way to travel is by means of imagination http://v2p.fr.eu.org http://www.obry.net gpg --keyserver keys.gnupg.net --recv-key F949BD3B This email is confidential and is intended for the addressee only. If you are not the addressee, please delete the email and do not use it in any way. Please note that any views or opinions presented in this email are solely those of the author and do not necessarily represent those of the company. NHBC reserves the right to monitor all email communications. The recipient should check this email and any attachments for the presence of viruses. The company accepts no liability for any damage caused by any virus transmitted by this email. NHBC, the National House-Building Council, is limited by guarantee in England, No 320784. Registered address: NHBC House, Davy Avenue, Knowlhill, Milton Keynes MK5 8FP. NHBC is authorised by the Prudential Regulation Authority and regulated by the Financial Conduct Authority and Prudential Regulation Authority. NHBC Building Control Services Ltd, registered by guarantee in England with Company No. 01952969. Registered address: NHBC House, Davy Avenue, Knowlhill, Milton Keynes MK5 8FP. NHBC Services Ltd registered by guarantee in England, No 03067703. Registered address: NHBC House, Davy Avenue, Knowlhill, Milton Keynes MK5 8FP. If you make a claim under a Buildmark policy your personal details will be stored and processed in accordance with the Data Protection Act. Your personal details may be passed to others involved with your claim such as the original builder, or a consultant or remedial works contractor that we may employ in connection with your claim(s) and matter ancillary to your claim(s). Other than disclosure provided for in this statement, we will not pass any data about you to any other party without your permission unless we are required to do so by law. ------------------------------------------------------------------------------ BPM Camp - Free Virtual Workshop May 6th at 10am PDT/1PM EDT Develop your own process in accordance with the BPMN 2 standard Learn Process modeling best practices with Bonita BPM through live exercises http://www.bonitasoft.com/be-part-of-it/events/bpm-camp-virtual- event?utm_ source=Sourceforge_BPM_Camp_5_6_15&utm_medium=email&utm_campaign=VA_SF _______________________________________________ Darktable-users mailing list Darktable-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/darktable-users
