One thing that is interesting is greyhole, https://www.greyhole.net/, it is a storage pool technology which leverages samba. You connect as many disparate sized drives as you like. When you copy a file into the pool it makes as many copies of the file across different disks as you have configured.
The nice thing is that it you can pull a drive out of the pool and plug it into another machine and just read the files from it unlike a drive from a raid array. There are some caveats, of course, the biggest ones being that greyhole doesn't like lots of small files or rapidly changing files, so don't have the download folder for torrent files in the greyhole pool. Cheers Lord Drachenblut On Sun, Nov 29, 2015, 5:32 PM John Syne <john3...@gmail.com> wrote: > Hi William, > > My comment was just a heads up so other developer’s don’t get take a hit > like I did. Just look at your disk SMART data and you will be surprised by > the number of errors on those disks. Here is an example of SMART info from > one of my 4TB WD disks I use with TimeMachine. As you can see, 0 errors in > the log. On my development system, I use 1TB Seagate SSD drives and they > work great. > > Last Checked : November 29, 2015 2:25:14 PM PST > Last Checked (ISO 8601 format) : 2015-11-29T14:25:14 > > Advanced SMART Status : OK > Overall Health Rating : GOOD 89.9% > Overall Performance Rating : GOOD 89.9% > Issues found : 0 > > Serial Number : WD-WCC4E0HHFLY1 > WWN Id : 5 0014ee 260fbf0bd > Volumes : TimeMachine1 > Device Path : /dev/disk4 > Total Capacity : 4.0 TB (4,000,787,030,016 Bytes) > Model Family : Western Digital Red > Model : WDC WD40EFRX-68WT0N0 > Firmware Version : 82.00A82 > Drive Type : HDD 5400 rpm > > Power On Time : 5,078 hours (7 months 1 days 14 > hours) > Power Cycles Count : 54 > Current Power Cycle Time : 22.1 hours > > > > === DEVICE CAPABILITIES === > S.M.A.R.T. support enabled : yes > DriveDx Active Diagnostic Config : Base config [hdd.default] > Sector Logical Size : 512 > Sector Physical Size : 4096 > Physical Interconnect : SATA > Removable : no > Ejectable : no > ATA Version : ACS-2 (minor revision not indicated) > SATA Version : SATA 3.0, 6.0 Gb/s (current: 6.0 > Gb/s) > Bay # : 1 > I/O Path : > IOService:/AppleACPIPlatformExpert/PCI0@0/AppleACPIPCI/PEG1@1 > ,1/IOPP/UPSB@0/IOPP/DSB2@4/IOPP/UPS0@0/IOPP/pci-bridge@3 > /IOPP/pci1b21,612@0/AppleAHCI/PRT0@0/IOAHCIDevice@0 > /AppleAHCIDiskDriver/IOAHCIBlockStorageDevice > Attributes Data Structure Revision : 16 > SMART Command Transport (SCT) flags : 0x703d > SCT Status supported : yes > SCT Feature Control supported : yes > SCT Data Table supported : yes > Error logging capabilities : 0x1 > Self-tests supported : yes > Offline Data Collection capabilities : 0x7b > Offline Data Collection status : 0x0 > Auto Offline Data Collection flags : 0x0 > [Known device ]: yes > [Drive State Flags ]: 0x0 > > > === CURRENT POWER CYCLE STATISTICS === > Data Read : 2.2 GB > Data Written : 3.5 GB > Data Read/Write Ratio : 0.62 > Average Throughput (Read) : 1.2 MB/s > Average Throughput (Write) : 932.4 KB/s > > Operations (Read) : 175,372 > Operations (Write) : 153,554 > Operations Read/Write Ratio : 1 > Throughput per operation (Read) : 12.9 KB/Op > Throughput per operation (Write) : 23.6 KB/Op > > Latency Time (Read) : 0 ns > Latency Time (Write) : 0 ns > Retries (Read) : 0 > Retries (Write) : 0 > Errors (Read) : 0 > Errors (Write) : 0 > > > === PROBLEMS SUMMARY === > Failed Indicators (life-span / pre-fail) : 0 (0 / 0) > Failing Indicators (life-span / pre-fail) : 0 (0 / 0) > Warnings (life-span / pre-fail) : 0 (0 / 0) > Recently failed Self-tests (Short / Full) : 0 (0 / 0) > I/O Errors Count : 0 (0 / 0) > Time in Under temperature : 0 minutes > Time in Over temperature : 0 minutes > > > === IMPORTANT HEALTH INDICATORS === > ID NAME RAW VALUE > STATUS > 5 Reallocated Sector Count 0 > 100% OK > 197 Current Pending Sectors Count 0 > 100% OK > 198 Offline Uncorrectable Sector Count 0 > 100% OK > 199 UDMA CRC Error Count 0 > 100% OK > > > === TEMPERATURE INFORMATION (CELSIUS) === > Current Temperature : 33 > Power Cycle Min Temperature : 27 > Power Cycle Max Temperature : 37 > Lifetime Min Temperature : 23 > Lifetime Max Temperature : 49 > Recommended Min Temperature : 0 > Recommended Max Temperature : 60 > Temperature Min Limit : -41 > Temperature Max Limit : 85 > > > === DRIVE HEALTH INDICATORS === > ID | NAME | TYPE | UPDATE | > RAW VALUE | VALUE | THRESHOLD | WORST | STATUS | > LAST MODIFIED > 1 Raw Read Error Rate Pre-fail online > 0x0 200 51 200 100% OK > 5/13/15 8:43 PM > 3 Spin Up Time Pre-fail online > 7,891 182 21 177 89.9% OK > 11/29/15 2:25 PM > 4 Start Stop Count Life-span online > 4,129 96 0 96 96.0% OK > 11/29/15 2:25 PM > 5 Reallocated Sector Count Pre-fail online > 0 200 140 200 100% OK > - > 7 Seek Error Rate Life-span online > 0x0 200 0 200 100% OK > - > 9 Power On Hours Life-span online > 5,078 94 0 94 94.0% OK > 11/29/15 2:25 PM > 10 Spin Retry Count Life-span online > 0 100 0 100 100% OK > - > 11 Calibration Retry Count Life-span online > 0 100 0 253 100% OK > - > 12 Power Cycle Count Life-span online > 54 100 0 100 100% OK > 11/28/15 4:19 PM > 192 Power-Off Retract Count Life-span online > 21 200 0 200 100% OK > 11/12/15 2:02 PM > 193 Load Cycle Count Life-span online > 9,125 197 0 197 98.5% OK > 11/29/15 2:25 PM > 194 Temperature (Celsius) Life-span online > 33 119 0 103 99.2% OK > 11/29/15 2:25 PM > 196 Reallocated Event Count Life-span online > 0 200 0 200 100% OK > - > 197 Current Pending Sectors Count Life-span online > 0 200 0 200 100% OK > - > 198 Offline Uncorrectable Sector Count Life-span offline > 0 100 0 253 100% OK > - > 199 UDMA CRC Error Count Life-span online > 0 200 0 200 100% OK > - > 200 Multi Zone Error Rate Life-span offline > 0 100 0 253 100% OK > - > > > > === DRIVE ERROR LOG === > error log is empty > > > === DRIVE SELF-TEST LOG === > self-test log is empty > > > Regards, > John > > > > > On Nov 29, 2015, at 1:42 PM, William Hermans <yyrk...@gmail.com> wrote: > > *. . .the only purpose of a RAID backup is to prevent a single point of >> failure (like a disk failure) resulting in lost backups.* > > > You do not need a RAID array to prevent a single point of failure. You > take those 3+ disks, put them in 3 different machines. Or even in the same > machine as single drives. Same difference, only less wear and tear on the > drives, more cost effective, and perhaps a small amount slower as singles. > > In the field you'll likely not run into any RAID 5/6 arrays. At least for > corporate storage. You're more likely to see RAID10, or RAID0 + 1. Because > there is nothing faster than striping disks, and RAID1 does not have an > impact on performance if set up correctly. RAID5/6 is just a way for the > home user to feel all warm and fuzzy . . and literally feed the companies > who offer the hardware for such arrays. Be it controllers, or "special" > hard drives . . . special software, chipsets with BS built in RAID( > software ). > > I still use Seagate drives(nothing but), and have no issues. Why ? > Probably because I do not run RAID. RAID is notorious for being hard on > drives. Especially RAID 5/6. I will admit, that Seagate's reputation has > gone into the toilette in the last 8 or so years. All their drives used to > be lifetime warranty. Now days I think they give 3 years . . . not even as > good as WD, or even Samsung SSDs . . . > > Anyway, seriously. Unless you're running a server that sees thousands+ of > transactions a day. You don't need RAID. But hey, don't pay attention to > me. . . > > > On Sun, Nov 29, 2015 at 1:44 PM, John Syne <john3...@gmail.com> wrote: > >> That makes perfect sense. BTW, the only purpose of a RAID backup is to >> prevent a single point of failure (like a disk failure) resulting in lost >> backups. >> >> One thing to pay attention to is the MTBF numbers for disks. I was a firm >> believer in Seagate Barracuda disk until I had a whole number of them fail >> over a few months. Speaking Seagate tech support, they explained that the >> SMART data on these disks showed they had more than the 3,000 hours MTBF >> and hence I should have expected them to fail. I couldn’t believe what they >> told me; running their disks 24 hours/day, they expected failures in 1/3 of >> a year. They were right, look at the SMART data on Seagate disks and you >> will see read write errors in the 10’s of thousands or more. >> >> After that I use Western Digital RED disks which are designed for 24/7 >> NAS applications. Looking at the disk SMART data, I see 0 read/write errors. >> >> Regards, >> John >> >> >> >> >> > On Nov 29, 2015, at 3:37 AM, c...@isbd.net wrote: >> > >> > John Syne <john3...@gmail.com> wrote: >> >> [-- text/plain, encoding quoted-printable, charset: UTF-8, 156 lines >> --] >> >> >> >> Yeah, but rsync only gives you a snapshot and not a history of your >> backup. >> >> When I really mess up, I want to go back to the state of my machine 15 >> >> minutes ago, or two days ago. This has saved me a lot of head >> scratching, >> >> trying to find out where I messed up. I really like the way timemachine >> > >> > I use an rsync based incremental backup system (I wrote it myself >> > having used rsnapshot for a while, rsnapshot is OK but I think it's >> > too complex). >> > >> > I do hourly incremental backups locally to another disk on my main >> > machine and I do daily incremental backups to a remote machine. The >> > daily remote backups get thinned out as they get older so there are >> > daily backups for the last month, then monthly ones for 12 months, >> > then yearly ones. >> > >> > -- >> > Chris Green >> > · >> > >> > -- >> > For more options, visit http://beagleboard.org/discuss >> > --- >> > You received this message because you are subscribed to the Google >> Groups "BeagleBoard" group. >> > To unsubscribe from this group and stop receiving emails from it, send >> an email to beagleboard+unsubscr...@googlegroups.com. >> > For more options, visit https://groups.google.com/d/optout. >> >> -- >> For more options, visit http://beagleboard.org/discuss >> --- >> You received this message because you are subscribed to the Google Groups >> "BeagleBoard" group. >> To unsubscribe from this group and stop receiving emails from it, send an >> email to beagleboard+unsubscr...@googlegroups.com. >> For more options, visit https://groups.google.com/d/optout. >> > > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > > > -- > For more options, visit http://beagleboard.org/discuss > --- > You received this message because you are subscribed to the Google Groups > "BeagleBoard" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to beagleboard+unsubscr...@googlegroups.com. > For more options, visit https://groups.google.com/d/optout. > -- Cheers Matthew "Lord Drachenblut" Williams -- For more options, visit http://beagleboard.org/discuss --- You received this message because you are subscribed to the Google Groups "BeagleBoard" group. To unsubscribe from this group and stop receiving emails from it, send an email to beagleboard+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
