WeeboTech Posted February 9, 2015 Share Posted February 9, 2015 My data drives are far from "read only".. FWIW, My term below was read-mostly. If there are allot of writes and there is high concern in using RAID0 as a "parity pool" (my new term now), then don't do it that way. It's pretty simple. Deal with performance or longevity on the SMR drive or pay the price for a high quality 8TB drive. The parity pooling suggestion was only to allow people alternatives. It's going to cost one way or another. Another option is to use an external RAID unit like the SANS DIGITAL TR4UTBPN 4Bay USB 3.0 / eSATA Hardware RAID 5 Tower RAID Enclosure http://www.newegg.com/Product/Product.aspx?Item=N82E16816111149 In this case you can choose RAID0, 1+0, RAID5, etc, etc via one eSATA port. While not as clean as an internal configuration, it's doable. Quote Link to comment
WeeboTech Posted February 9, 2015 Share Posted February 9, 2015 ... My real life experience is that there are tools running indexing those media folders, subtitles getting added, covers added.. My data drives are far from "read only".. Yet another reason why the parity drive isn't the "least important". Certainly is 'least important'. If parity dies, there is no data loss whatsoever, only protection. What's lost is the ability to rebuild a failed data drive rapidly should the need arise and not have to resort to backups. Quote Link to comment
garycase Posted February 9, 2015 Share Posted February 9, 2015 ... Certainly is 'least important'. If parity dies, there is no data loss whatsoever, only protection. If another drive dies, there's also no loss whatsoever, only protection. You can still read/write the disk (emulated); and can easily rebuild it. I agree that if you lose MULTIPLE drives, it'd be nice if one of them is parity, since that's one less disk's worth of data you'll lose. But in a fault-tolerant RAID I don't think any one drive is more or less important than any other. Quote Link to comment
WeeboTech Posted February 9, 2015 Share Posted February 9, 2015 ... Certainly is 'least important'. If parity dies, there is no data loss whatsoever, only protection. If another drive dies, there's also no loss whatsoever, only protection. You can still read/write the disk (emulated); and can easily rebuild it. Where we differ, while the drive is emulated the data exists, yet all you need is one pending sector during a rebuild that cannot be read and you've lost that whole drive. I speak from experience here. If during a parity rebuild a pending sector causes a failure, you can still access most of the data on the suspect drive. I suppose it's a matter of personal preference. i.e. considering the sense of urgency, a parity drive failure or a data drive being emulated. Quote Link to comment
WeeboTech Posted February 9, 2015 Share Posted February 9, 2015 I agree that if you lose MULTIPLE drives, it'd be nice if one of them is parity, since that's one less disk's worth of data you'll lose. But in a fault-tolerant RAID I don't think any one drive is more or less important than any other. I would like to add here, The reason for this side lined debate is due to the high level of concern in building and using an unprotected parity pool. The concern is that multiple drives for parity have a higher chance of failure. So, as stated above it'd be nice if one of them is parity chances are higher that this will be the case, according to beliefs presented. In any case, it's still all about your level of concern and budget. Quote Link to comment
garycase Posted February 9, 2015 Share Posted February 9, 2015 The real issue is that with the size of modern drives, large arrays NEED to be dual fault-tolerant, so a rebuild will still work okay if there's a 2nd failure during the process. Dual parity should be high on the list of future enhancements !! Quote Link to comment
Helmonder Posted February 9, 2015 Share Posted February 9, 2015 The real issue is that with the size of modern drives, large arrays NEED to be dual fault-tolerant, so a rebuild will still work okay if there's a 2nd failure during the process. Dual parity should be high on the list of future enhancements !! +1 Quote Link to comment
WeeboTech Posted February 9, 2015 Share Posted February 9, 2015 The real issue is that with the size of modern drives, large arrays NEED to be dual fault-tolerant, so a rebuild will still work okay if there's a 2nd failure during the process. Dual parity should be high on the list of future enhancements !! Yes, Obviously. No one's disputing the importance of fault tolerance, large arrays and dual parity. The debate has been about risks with a cost effective method to satisfy a potential performance/budget issue until a better solution comes around. It boils down to the prior discussion of how much are you willing to pay for the higher percentage of uptime. Really, we don't know anything until there is long term data of the Seagate Archive drive in a parity role. Quote Link to comment
TSM Posted February 9, 2015 Share Posted February 9, 2015 The real issue is that with the size of modern drives, large arrays NEED to be dual fault-tolerant, so a rebuild will still work okay if there's a 2nd failure during the process. Dual parity should be high on the list of future enhancements !! +1 + Infinity All this talking back and forth about what drives are most important. All my drives are important. I don't want any of them to die. I had a drive die about 6 months ago and I did not enjoy the experience. Dual parity would have made it much more pleasant. Quote Link to comment
WeeboTech Posted February 9, 2015 Share Posted February 9, 2015 The real issue is that with the size of modern drives, large arrays NEED to be dual fault-tolerant, so a rebuild will still work okay if there's a 2nd failure during the process. Dual parity should be high on the list of future enhancements !! +1 + Infinity All this talking back and forth about what drives are most important. All my drives are important. I don't want any of them to die. I had a drive die about 6 months ago and I did not enjoy the experience. Dual parity would have made it much more pleasant. Double Drive failure? Quote Link to comment
TSM Posted February 9, 2015 Share Posted February 9, 2015 The real issue is that with the size of modern drives, large arrays NEED to be dual fault-tolerant, so a rebuild will still work okay if there's a 2nd failure during the process. Dual parity should be high on the list of future enhancements !! +1 + Infinity All this talking back and forth about what drives are most important. All my drives are important. I don't want any of them to die. I had a drive die about 6 months ago and I did not enjoy the experience. Dual parity would have made it much more pleasant. Double Drive failure? No. But until I was able to replace the drive that died I felt extremely on edge and agitated. And no I don't have a good back up plan, and I know that parity is not the same as a good backup, but I still desperately want dual parity. Quote Link to comment
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