This is very detailed, with lots of good information. If the user scrubs their pools or otherwise reads all their data at least quarterly, the risk for a home user is minimal. Show : My System Specs FreeNAS: 9.10 Motherboard: ASRock E3C226D2I Mini-ITX Server Motherboard CPU: Intel Xeon E3-1271 v3 Quad-Core 3.6GHz 8MB LGA 1150 CPU cooler: Thermalright TRUE Spirit 120M(BW) Rev.A RAM: i.e. navigate here
permalinkembedsaveparentgive gold[–]txgsync 1 point2 points3 points 1 year ago(18 children) It may even help you survive if you encounter an URE with 2 drives lost in a RAIDZ2. Mostly this happens when there's problems with the disk shelf backplane or fibre loop in the old days. Related Point: "Enterprise" 10,000 - 15,000 RPM drives often show much better reliability statistics over time in large part because they are short-stroked from the factory. Clustering issues.
It is simply gone. You're welcome. That chaos might be some file you don't care about being inaccessible, or it might take the whole pool down.
Reply Tim says: October 17, 2013 at 12:22 pm I think everyone is forgetting that these large drives are not using 512b sectors; they use the Advance Format sector size of They want it cheap, fast, and reliable. In theory, I shouldn't be able to rebuild a failed RAID 5 array using 6TB drives that have a 10^14 BER. Ure Raid 5 ZFS has wonderful management benefits over tradition raid, and the block checksum can detect errors in the IO chain that simple RAID levels cannot, but as far as I am aware
Getting your tongue around foreign tech-talk is easier than you think Topless in-car selfie attempt climaxes with rear-end bonking More like this Sandisk Flash Data Center Storage Flash banishes the spectre Unrecoverable Read Error Ure Overall, this is simple risk assessment, mitigation and management. skis4hire Joined: May 28, 2014 Messages: 3 Thanks Received: 0 Trophy Points: 1 The purpose of RAIDZx is to prevent the need to re-create your zpool from backup if x drives The chance of one URE happening is 1/(10^14) for every bit read.
Synology DS209 (4.1.2668) DS212+ (4.1.2668) Top Charles Hooper Experienced Posts: 114 Joined: Thu Aug 29, 2013 9:27 pm Re: This BS called URE Quote Postby Charles Hooper » Tue Jan 27, Zfs Ure But without 100% backups I'd have data loss (for most it would be pretty significant data loss too). With such a huge spare sector pool, it's no wonder failures are hidden for so long. SearchCloudStorage Igneous Systems delivers IaaS with hyperscale nano servers Igneous Systems offers IaaS that uses nano servers to store data on- premises and is managed by the vendor remotely on a
There is this article in ComputerWorld by Jerome Wendt, talking about why "using SATA drives to store large amounts of de-duplicated data is not always the match made in heaven that It is generally thought to be a good thing that they are setting reasonable expectations and exceeding them - assuming they are. What Is Unrecoverable Read Error I'm running a RAID6 of 18 drives and a RAID6 of 6 drives in a single pool for a year or more and can confirm that ZoL nicely balances everything over Unrecoverable Read Error Nero Eight years after the article was written in 2007, Diskageddon has not yet occurred in large part because engineers in the industry worked our collective asses off to make sure it
Well, there are at least 2 copies of all metadata in ZFS, each with their own parity data (zpool-critical metadata is stored 3x). check over here [email protected]:~# zpool iostat -v storage capacity operations bandwidth pool alloc free read write read write ------------------------------ ----- ----- ----- ----- ----- ----- storage 36.0T 50.8T 819 42 99.2M 3.22M raidz2 7.13T However, this problem of error rates, rather than full drive failures, has been under the radar for most sysadmins. That's where I am confused. halfcat 777 days ago Say we have a department of a company with 36 employees, and one pair of dice. Unrecoverable Read Error Rate Ssd
You also need to consider that when you put a bunch of disks together and one disk fails, the chances of another disk failing within 4 hours increases spectacularly. At worst, the array could fail the drive with the read error, causing the system to see two bad drives at once. Visualist Apr 18, 2015 Re: Enterprise drives for NAS & Data Vernon D Rainwater Apr 17, 2015 Re: Enterprise drives for NAS & Data Visualist Apr 18, 2015 http://crimsonskysoftware.com/unrecoverable-read/unrecoverable-read-error-at-lba-256.html So I believe that the calculation made by Robin Harris in his 2009 article is a bit of an extreme case.
If the drive gets so stale the CRC can't protect it (or if the CRC itself goes bad), then the drive may punt bad data to the OS (or fail the Ure Rate Especially if you have an attachment to the continued use of RAID 5. Very cool feature.
It took them two years to realize this problem in the firmware, and in that time that entire track would get most of the rust worn off it due to air In JDEC endurance testing, for instance, the UBER values for SSDs are lifetime values for the sample of solid state drives being assessed and a sector containing corrupted data is counted Not saying you are wrong, just saying I am unsure of the term used in the comments.. Raid 6 All are set to sleep when not used.
However, there may be reasons why your organisation hasn’t made the move, including concerns around security, disrupting productivity or the cost of adoption. August 12, 2015 at 4:17 AM Post a Comment Newer Post Older Post Home Subscribe to: Post Comments (Atom) Blog Rules Posts and comments are copyright of their respective authors who, permalinkembedsaveparentgive gold[–]mercenary_sysadmin 0 points1 point2 points 1 year ago(1 child)Also, there's something you should really think about here: the lies told by vendors on their spec sheets Why would vendors lie on their http://crimsonskysoftware.com/unrecoverable-read/unrecoverable-read-error-at-lba-dvd.html I will encounter a URE before the array is rebuilt and then I’d better hope the backups work.
While this is a more expensive option, it provides you with the best quality drives possible. These flash drives would also rebuild so fast there's less of a window for an error to occur (or for another drive to fail due to the stress of taking days Well, I had a pair of WD Greens that wrote tens of thousands of corrupt blocks a day for a few weeks before I figured out what was going on. (And That's why VMFS supports disks above 2 TB now.
Top SparrowHawk Sharp Posts: 161 Joined: Thu Nov 15, 2012 1:33 pm Re: This BS called URE Quote Postby SparrowHawk » Mon Jun 01, 2015 10:29 am Hi,I assume a URE The checksumming is not how ZFS saves you BTW, it's the fact that ZFS does file-level RAID and not block level RAID right? Also, the risk is significantly reduced - as stated by txgsync - if the user reads all data or does a scrub of the data - at least quarterly. In most environment a high percentage of data is at rest, leaving only a few percent of hot data (working set).
First, some clarification. The stuff that doesn't have multiple copies is where your system gets boned. I stand corrected regarding the URE rating of those drives.I did a bit of searching - it is the Western Digital Se drives that have the atypical URE rating of <10 e.g.
What errors does your hardware return, and in what way? The associated media assessment measure, unrecoverable bit error (UBE) rate, is typically specified at one bit in 10^15 for enterprise-class drives (SCSI, FC or SAS), and one bit in 10^14 for permalinkembedsaveparentgive gold[–]txgsync 1 point2 points3 points 1 year ago(0 children) TheUbuntuGuy makes a great point that the URE rate will change over the drive lifetime. Consumer SSD error rates are 10^16 bits or an error every 1.25PB.
The Real World Now, there are some great, and not so great, articles out there which go into a lot of detail about this problem. I can't say the Solaris solution of "exclude the really full disks until the empty ones are close" is a whole lot better, either. That means that a six terabyte array being resilvered has a roughly fifty percent chance of hitting a URE and failing."I have a degree in mathematics - but I have been Not that RAIDZ1 is 100% to blame for all of them, but usually if someone is going with RAIDZ1 they are cutting every single corner they can (reusing that spare hardware
SearchDisasterRecovery Dell Services elevates Alabama city's DR plan with the cloud After a massive tornado touched down across the state, the city of Opelika, Ala., looked to the cloud to get OK, he did put the SAS in a RAID 5 array, and the SATA in a RAID 6, with it's double parity striping, and higher failure tolerance.