Overclockers Australia Forums

OCAU News - Wiki - QuickLinks - Pix - Sponsors  

Go Back   Overclockers Australia Forums > Specific Hardware Topics > Storage & Backup

Notices


Sign up for a free OCAU account and this ad will go away!
Search our forums with Google:
Reply
 
Thread Tools
Old 14th March 2017, 7:43 PM   #271
elvis Thread Starter
Old school old fool
 
elvis's Avatar
 
Join Date: Jun 2001
Location: Brisbane
Posts: 28,120
Default

Here's a great example of why we want direct access to hard disks, without RAID controllers getting in the way:

http://changelog.complete.org/archiv...uption-is-real

Silent corruption due to a bad SATA cable. Only happens on rare occasion, completely invisible to the hardware and OS without a next gen filesystem to detect it.
__________________
Play old games with me!
elvis is offline   Reply With Quote

Join OCAU to remove this ad!
Old 15th March 2017, 6:30 AM   #272
Doc-of-FC
Member
 
Doc-of-FC's Avatar
 
Join Date: Aug 2001
Location: Canberra
Posts: 2,576
Default

Quote:
Originally Posted by elvis View Post

http://changelog.complete.org/archiv...uption-is-real

Silent corruption due to a bad SATA cable. Only happens on rare occasion, completely invisible to the hardware and OS without a next gen filesystem to detect it.
Not always, SMART attribute 199, usually helps lead to predictive failure detection. We've used it to replace a faulty SAS backplane.
Quote:
UltraDMA CRC Error Count
The count of errors in data transfer via the interface cable as determined by ICRC (Interface Cyclic Redundancy Check).
Usually indicative of a bad cable, guy I work with found out by monitoring his smart data on freenas, sata connector with a slightly too great a bend radius at the drive interface. No reported data issues during scrubs, so retries do occur successfully.
Doc-of-FC is offline   Reply With Quote
Old 15th March 2017, 12:39 PM   #273
elvis Thread Starter
Old school old fool
 
elvis's Avatar
 
Join Date: Jun 2001
Location: Brisbane
Posts: 28,120
Default

Quote:
Originally Posted by Doc-of-FC View Post
Not always
Sure. But sometimes.

Current SMART implementations and various RAID data verification levels catch most errors. But the summary of this thread is that as we approach petabyte workloads, we're getting to much higher chances of things getting through unnoticed.

Direct drive access with per-block verification at every read and write, along with scheduled scrubbing to get the read (and thus verification) levels up is now becoming a mandatory feature of any new file system. Any legacy file system that is dealing with hundreds of terabytes or more and doesn't offer this level of verification is soon going to become a data integrity problem for people relying on them to hold their important data long term.

This is a problem of probability and scale. A 0.00001% chance of something bad happening per bit approaches 1 as the number of bits gets much, much bigger.
__________________
Play old games with me!
elvis is offline   Reply With Quote
Old 19th March 2017, 7:35 PM   #274
domsmith
Member
 
Join Date: Nov 2002
Posts: 192
Default

Anyone had a chance to try out Freenas Corral yet?

Docker integration looks pretty good.

domsmith is offline   Reply With Quote
Old 21st March 2017, 8:02 PM   #275
davros123
Member
 
Join Date: Jun 2008
Posts: 2,707
Default

1. That guy should not do videos.
2. That's the worst explanation for some marketing bullshit reason to change a number based versioning system I have ever heard
3. I like the dash
__________________
Want a nas, you may find my Esxi/Solaris ZFS NAS build thread of interest.
Quote:
Originally Posted by Stanza View Post
yeah well I just reported my own post...ferk....
Quote:
Originally Posted by Blinky View Post
If you have become content with the size of your e-penis, sticking clear of rack mounted stuff will save you heaps of $$$.
davros123 is offline   Reply With Quote
Reply

Bookmarks

Sign up for a free OCAU account and this ad will go away!

Thread Tools

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT +10. The time now is 3:25 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.
OCAU is not responsible for the content of individual messages posted by others.
Other content copyright Overclockers Australia.
OCAU is hosted by Micron21!