5 ms·
Rebuild times pretty much forced me out of Raid5 and into a Raid10 after I encountered a secondary drive failure during rebuild. Luckily it was my raid controll
by blackflame7000 10y ago
Rebuild times pretty much forced me out of Raid5 and into a Raid10 after I encountered a secondary drive failure during rebuild. Luckily it was my raid controller pre-flagging questionable sectors that weren't actually reallocated so I was able to recover but now I always like to keep 2 independent backups. I use SFP-10gb links between computers to move files and even that is painfully slow transferring terabytes. You're right, The cloud is in many ways less practical until the bandwidth is available to access it all.
- bigiain 10y agoYep - it's been a long time since raw storage costs were so high I couldn't justify and afford to use raid 0 [Edit: Raid 1 not 0 - as DuskStar corrected me...) for everything that matters. Whenever I buy drives these days, I buy three of them at a time (if possible, the same size drives from at least two different vendors or batches from the same vendor).
- walrus01 10y agonobody should ever be using raid5 anymore, and that's been true for many years: http://www.zdnet.com/article/why-raid-5-stops-working-in-2009/ http://www.zdnet.com/article/why-raid-5-stops-working-in-200... the use cases for raid5 have pretty much been replaced with raid6 plus hotspare.
- kristianp 10y agoThere's a followup to that article that says Raid 6 won't be recommended by 2019. http://www.zdnet.com/article/why-raid-6-stops-working-in-2019/ http://www.zdnet.com/article/why-raid-6-stops-working-in-201...
- walrus01 10y agoYeah, that is indeed scary, and something to be taken into account for disaster recovery planning. Off site backups of systems need to be designed so that the whole RAID array can be physically destroyed (fire, flood, theft, axe, etc) and recovery will not take a ridiculous amount of time. The wise sysadmin mantra of "RAID is not a backup" must be kept in mind at all times.
- XorNot 10y agoZFS in RAIDZ2 mode. Unless 3 drive controllers die simultaneously, you can survive finding faults during a full rebuild.
- Dylan16807 10y agoRaid 10 still leaves you vulnerable to a second drive failure. I'd personally jump from a multiple parity scheme to at least raid 5+1 without ever stopping at 1+0. (Though probably something with checksums instead of naked redundancy.)
- myrandomcomment 10y agoUsing FreeNAS I have 4x4TB drives. 2 mirror sets that are mirrors of each other. Only 7.25TB total space but I am not to worried about a failure. Disk are cheap, loosing 16 years of family photos, not so much.
- Filligree 10y agoThat's basically why I've gone with raidz3, yeah. raid10 still allows a second drive failure to lose data, it's just less likely to be that specific paired drive.
- fnj 10y agoRAID-Z3, or a mirror of two RAID-Z2s for me, I have one of each. You can also do mirrors with more than just two elements.
- rb666 10y agoGood article here: http://jrs-s.net/2015/02/06/zfs-you-should-use-mirror-vdevs-not-raidz/ http://jrs-s.net/2015/02/06/zfs-you-should-use-mirror-vdevs-...
- Dylan16807 10y ago> The only disk more heavily loaded than usual during a mirror vdev resilvering is the other disk in the vdev – which might sound bad, but remember that it’s only being heavily loaded with reads, whereas all of the remaining disks in a RAIDZ vdev are being much more heavily loaded with writes as well as reads during a resilver. Why is that happening? There's no reason to perform a bunch of writes to those drives.