pico Posted December 11, 2014 Share #21 Posted December 11, 2014 Advertisement (gone after registration) The problem arises when the housing dies like it did for my DataTank. You are then left with 4 unreadable hard discs. Wilson Can the controller be replaced in order to save the SSD? . Link to post Share on other sites More sharing options...
Advertisement Posted December 11, 2014 Posted December 11, 2014 Hi pico, Take a look here Memory card issue. I'm sure you'll find what you were looking for!
wlaidlaw Posted December 11, 2014 Share #22 Posted December 11, 2014 Freecom say that no spare parts are available and you would need an identical chipset and firmware in order to read the pair of RAID 0 drives. I bought a new power supply from Lacie, who used the same one as Freecom, in the vain hope that it was just a PSU issue but no luck. I have been doing a lot of reading on this over the last few days and people say RAID is not primarily for safe back up for for fast access. Back up is best done by multiple copies, which luckily for the most part, I had done. With most hard discs having a maximum write speed of around 120mb/s, using a RAID 5 quad array nearly quadruples the write speed of the system, if you are using a fast enough pipe, like Thunderbolt or USB3 or even Firewire 800. The problem I have is too much image data spread across various machines. What I should really get, is a pair of fast big raid systems of say 8TB and get all my image data, properly indexed onto one of them and them set up mirroring between them. I have found that failure of the RAID housing appears to be almost as common as the failure of a modern server grade hard discs within the array, which somewhat negates the purpose of them. Software RAID systems, such as the OWC Thunderbay, may offer a better chance of data recovery in the event of the RAID hardware failure, than the more common hardware RAID systems, where a custom control chip and firmware is used. Wilson Link to post Share on other sites More sharing options...
CheshireCat Posted December 11, 2014 Share #23 Posted December 11, 2014 a four rotating disc housing with 1.5TB discs and using it with RAID 5.0 or whatever the current fashion is. The problem arises when the housing dies like it did for my DataTank. You are then left with 4 unreadable hard discs. RAID 5 is nonsense for personal usage. With normal disks you want two big disks with RAID 1. If a disk breaks, with most software and hardware RAID 1 implementations, you can read the other disk just fine. On the Mac I use for photos there is no RAID. Just an extra big fat disk for Time Machine. So convenient and zero RAID hassles. Link to post Share on other sites More sharing options...
DigitalHeMan Posted December 11, 2014 Share #24 Posted December 11, 2014 RAID 5 is nonsense for personal usage. With normal disks you want two big disks with RAID 1. If a disk breaks, with most software and hardware RAID 1 implementations, you can read the other disk just fine. On the Mac I use for photos there is no RAID. Just an extra big fat disk for Time Machine. So convenient and zero RAID hassles. Why do you think it's nonsense? If you have multiple disks then RAID 1 is no longer practical, whereas RAID 5 can withstand a single disk failure and rebuild the downgraded array once a replacement disk is installed. My time machine and back up drive runs on a RAID 5 Qnap NAS. I wouldn't be able to do this on a single or pair of drives in RAID 1 due to size constraints. Link to post Share on other sites More sharing options...
CheshireCat Posted December 11, 2014 Share #25 Posted December 11, 2014 Why do you think it's nonsense? If you have multiple disks then RAID 1 is no longer practical. Because the capacity of a single disk grows faster than I (and most people for personal use) can fill it. When my disk is almost full, I buy one which is twice the size. Even if you work on raw videos, it is hard to need more than 8TB of storage for a single project. But there may be exceptions Link to post Share on other sites More sharing options...
wlaidlaw Posted December 12, 2014 Share #26 Posted December 12, 2014 The problem is the write speed of a single rotating hard disc. With the size of M240 16 bit TIFF's they gobble up data space like mad. Even the 8 bit ones are big enough and scanned medium format TIFF files at 4800 dpi are huge. Where you are downloading say 1500 to 2000 images to a hard disc, the speed limitation of a rotating disk makes it a long task. As the Thunderbolt 1 ports that I have on my MBP, can download at around 8 times the write speed limitation of a rotating disc, RAID improves things a lot. Having a quad RAID 5 or 6 set up can quadruple that write speed. I was amazed how long it took to make a new back up with a new Firewire 800 connection single external disc, from the 80% full 1TB hard disc in my iMac, which was the machine that used to back up to the dead FreeCom Datatank. I have given up on Time Capsule/Time Machine for the moment with the flaky wifi problems caused by Yosemite on my Retina Mac Book Pro. I will go back to it when Apple sort the wifi (hopefully on 10.10.2). I have twice had to delete and rebuild my Time Machine back up since upgrading to Yosemite, due to the sparse bundle becoming corrupted. Wilson Link to post Share on other sites More sharing options...
pico Posted December 12, 2014 Share #27 Posted December 12, 2014 Advertisement (gone after registration) How does RAID work with Photoshop when we assign multiple spindles for work space (Adobe's proprietary swapping)? . Link to post Share on other sites More sharing options...
CheshireCat Posted December 12, 2014 Share #28 Posted December 12, 2014 How does RAID work with Photoshop when we assign multiple spindles for work space (Adobe's proprietary swapping)?. Sucks compared to RAM speed. If you need fast, just load your system with RAM. Link to post Share on other sites More sharing options...
CheshireCat Posted December 12, 2014 Share #29 Posted December 12, 2014 The problem is the write speed of a single rotating hard disc. With the size of M240 16 bit TIFF's they gobble up data space like mad. A crappy drive will load your image to RAM in fractions of a second. The problem is not HD write speed at all, the problem is all the processing that is required. Link to post Share on other sites More sharing options...
wlaidlaw Posted December 12, 2014 Share #30 Posted December 12, 2014 I think you are misunderstanding what I do. After a trip where I might have taken 4000 images, I will probably sort them down to 1500 but then want them off my main travel work machine (the retina MBP with a 750GB SSD). I set this up as a named and dated library, broken down into each separate location I was at and load it off to a pair of mirrored external hard drives. When I want to look at that library again, I have to load it up from the external hard drive. I used to use a PowerMac with 4 x 1.5 internal TB drives plus iPhoto and could keep everything in one machine but that became too old, would not run up to date Intel software and is just now used as a family central server. I do really need drives with a fast write/read speed. I now use Capture One Ver. 8 Pro as my library system. The choice is either a pair of high capacity (say 4GB) SSD drives or a pair of 4 bay RAID housings. I just don't fancy getting stuck again with a drive housing, which has failed and the discs, although working themselves, are unreadable, as they need the specific control chip and firmware to read their particular variety of RAID. The discs out of the FreeCom DataTank, would not even mount, the formatting was so specific. They tested out OK, so could be reused if I reformat them but I am not going to, due to their age (about 4 to 5 years). Wilson Link to post Share on other sites More sharing options...
CheshireCat Posted December 12, 2014 Share #31 Posted December 12, 2014 I do really need drives with a fast write/read speed. I still don't undrestand why you need a fast hard drive. When you are transferring images, the bottleneck will typically be your USB2 interface, as most disks have transfer speeds well above 50 MB/sec, i.e. two Leica M raw files per second. Once they are in the external hard drive, to review each photo will require a 0.5 second to load data from drive to RAM, plus extra Capture One processing time required for rendering to display, a good program would load the next image while processing the current one, effectively hiding the 0.5 seconds load time (which, honestly, is not a big deal). Link to post Share on other sites More sharing options...
wlaidlaw Posted December 12, 2014 Share #32 Posted December 12, 2014 If you had read my posts, you would see that I have USB3/Thunderbolt and Firewire 800, so the disc IS the limitation not the pipe. It is nearer 1 second per image and if I am loading a library with 2000 or 3000 images, that is the best part of an hour. I do not necessarily want to look at the photos in the order they load but jump around. I am not going to change the way I work but will optimise the equipment to suit as best I can. You may work one way but I work another. Wilson Link to post Share on other sites More sharing options...
CheshireCat Posted December 12, 2014 Share #33 Posted December 12, 2014 If you had read my posts, you would see that I have USB3/Thunderbolt and Firewire 800 Sorry, I had not re-read all your previous posts. So the disc IS the limitation not the pipe. It is nearer 1 second per image and if I am loading a library with 2000 or 3000 images, that is the best part of an hour. If you had read your post , you said that most hard drives have a write speed of 120 MB/s (which is faster than a Firewire 800, note the uppercase "B"). If you do the math, you should be able to transfer about 5 raw images per second, but you currently get only 1 (i.e. about 25 MB/s). Therefore, you do not need RAID 5, you just need to understand what's wrong with your system and/or process. Link to post Share on other sites More sharing options...
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