Consider the failure possibilities:
1 drive, and RAID/SHR2 will probably cope without loss of data, or appreciable loss of throughput So a drive has failed You going to just replace the failed drive with one of a similar capacity? Remember 1) Rotating-Drive access is usually faster (maybe 30%) at the lower LBA addresses than at the higher ones 2) Yearly cost per byte becomes better as the sweet-spot capacity increases last year was 1~2TB, now 2~4TB 3) If 1 drive fails and you bought (say 6) of the same model with consecutive? Serial numbers does that mean you should expect the others to fail soon 4) Re 1,2,& 3 above would it be appropriate to replace all drives with new bigger ones NOW the old ones being used to upgrade less important facilities, or even just for user PCs So the motherboard fails either it didnt take more than 1 (or 2) drives and your data is OK so just replace the motherboard, reinstall all the software and carry-on 1) New PSU for the small cost why not 2) New motherboard, CPU and Memory all will be faster than the old one. assuming that you can use the same software on new kit to access the original data as it is on the drives. Or the motherboard fails and takes the drives with it well at least knackers the controlling/usage descriptor blocks and part of the file allocation table recovery being?? 1) New PSU for the small cost why not 2) New motherboard, CPU and Memory all will should be faster than the old one well you will be looking at a years worth of capability increases and price reductions 3) New drives again capability increases and price reductions maybe go for bulk SSD, or even hybrid drives 4) And rebuild the RAID etc. from backup remember the failure took most (if not all) drives attached at the time of failure Re 4 yes been there and failure was at the time I was backing up to external media so that went too! Backup to external media will be via comms, Wireless preferably, or at least non-electrically conductive sheathed fibre optic from now on. Well I can hope we dont get mains supply failure as it happened a few years ago rainwater into the mains under the street causing high frequency drops and then surges that took out the comms kit and the computer systems including the ones where the UPS was more than just a bit past-it. Surprise surprise the standby project test system survived I had built that way back in 2000 selecting components that were old tech enough to have no real price penalty. 1GHZ CPU, 4 x 265 MB memory and 8 x 120GB PATA drives with onboard hardware raid, and a well over-rated PSU Just a new comms board, and it is still working! Problem is its at max memory for the motherboard which practically means not for Win7 or associated server type software From: [email protected] [mailto:[email protected]] On Behalf Of J- P Sent: Wednesday, January 21, 2015 1:55 AM To: NT Subject: RE: [NTSysADM] SHR vs Traditional RAID/RED drives and that is why I will elect to use 6 discs in the array, and use the remaining 2 , to backup the critical data from the raid 6 array. Jean-Paul Natola _____ From: [email protected] To: [email protected] Subject: RE: [NTSysADM] SHR vs Traditional RAID/RED drives Date: Wed, 21 Jan 2015 01:43:04 +0000 Just to add: My Synology DS2413+ got corrupted about a year ago and I effectively lost all of my data. At that time, I posed the question to Synology as to what they recommended when I set up the server again SHR2 or RAID6. I was informed that while both options technically will work, they recommended RAID 6 over SHR2 for 7 or more hard drives for reliability. -Aakash Shah From: [email protected] [mailto:[email protected]] On Behalf Of James Button Sent: Tuesday, January 20, 2015 9:39 AM To: [email protected] Subject: RE: [NTSysADM] SHR vs Traditional RAID/RED drives My point is that you need to have a reasonable recovery concept (and frequently proven process) to deal with a hard drive failing mirror or rebuildable striping And that should include the possibility that it may be the NAS housing that fails possibly taking the drives with it. And the data on the still OK drives not being in a structure accessible by any other OS you have to hand. Yes if you need speed striping etc. or maybe a large set of small drives ( 2¼ laptop ones maybe TomsHardware did a project a long while ago comparing throughput on a large number of small drives vs a small number of large drives, and the conclusion was the small drives option was much faster, used a lot less power just needed more PSU and connection considerations - as in massed add-in drive controller boards. For those considering faster storage access SSD is the easy way, alternatively go the volume way or attach partitions of several drives as folders of an NTFS OS/filestore partition/drive. HOWEVER do make sure that : 1) The PSU can manage the drives powering up at system startup. 2) The BIOS can manage the drives maybe delay/sequenced power up at system startup. 3) The OS can manage that much MFT data being scanned etc. at startup. 4) There is sufficient real memory to manage the combined MFT data without massive paging of memory I have a win7 ultimate system that gets itself into knots if there are more than 2 2TB drives USB attached at startup. It happily runs with 5 drives attached if they are started up sequentially as in wait for the windows explorer to sho a drive before connecting the next and connecting means the interface cable, not just the power-brick JimB From: <mailto:[email protected]> [email protected] [ <mailto:[email protected]> mailto:[email protected]] On Behalf Of J- P Sent: Tuesday, January 20, 2015 5:09 PM To: NT Subject: RE: [NTSysADM] SHR vs Traditional RAID/RED drives My initial thought was raid 10 using 4tb (as thats what I use for servers) but I was reading about their SHR and it sounded interesting in that you can use different size drives and not lose any space The MEDIA data that is stored, is not "active" they do a job, transfer it there, after 6 months it gets erased. but I plan to use the additional storage for doing local server backups as well. (I do back up there servers off-site but its not realistic to pull 3TB over the wire). MY thought was 6 drives in raid10, then use the 2 remainig drives to copy what is deemed critical off the raid10 _____ Date: Tue, 20 Jan 2015 08:44:00 -0800 Subject: Re: [NTSysADM] SHR vs Traditional RAID/RED drives From: [email protected] To: [email protected] The WD NAS drives are only rated for groups of up to 6 and aimed squarely at the consumer market. They're rated for something along the lines of 180TB/year and only an error rate of 1x10^14. The Red Pro drives are slightly better and built for 8-16 bay units backed by a 5 year warranty, have a 7.2K speed and a much better 1x10^15 error rate and warrantied for 550TB/year written, also dropping in capacity to 4TB. If data is critical then move to their WD RE series drives again a 550TB/year rating along with 7.2K spindle and 5 year warranty with an even better 1x10^16 error rate. If you need the density you pay for it in reliability currently, be prepared to keep multiple copies. You mentioned 'terabytes of data' - how hot/cold is it? Also if you're using anything above 1TB drives please don't use RAID5 you'll just be kicking yourself later :( Nathan Shelby Lead Systems Engineer <https://quotewizard.com/> Quote Wizard <mailto:[email protected]> [email protected] / 206-753-2626 Malo Periculosam Libertatem Quam Quietum Servitium On Tue, Jan 20, 2015 at 8:00 AM, J- P <[email protected]> wrote: Hi all, I'm looking to drop one of these in at customer site, https://www.synology.com/en-us/products/DS1815+ I'm curious to know if anyone has elected to use their proprietary raid SHR/SHR2, and if so how it stacks up to traditional raid in terms of performance. And on a separate note , has anyone jumped onto the WD RED "NAS" drives yet? I like the idea of 6TB for 270.00, but not crazy about 54k speed or 3 yr warranty http://www.amazon.com/Western-Digital-3-5-inch-IntelliPower-WD60EFRX/dp/B00LO3KR 96/ref=pd_bxgy_pc_text_y however , 226.00 for a 4TB 72k with a 5 year warranty does sit a little better http://www.amazon.com/dp/B00LO3KRM8 any feedback is appreciated
