Rob's Other Links
- Special:Recentchanges to the unRAID Wiki within the last week, and within the last month
- Categories --- Orphaned Pages --- Blocked Users and IPs --- User List
- Wiki Logs --- unRAID Wiki Statistics --- Wiki Version --- Most Popular Pages
- The Analysis of Drive Issues; Drive Symbols
- Boot Codes
- Check Disk Filesystems
- Console commands
- FAQ and the FAQ for unRAID v4 and v5
- Files on v6 boot drive
- Fixing a drive with red status indicator
- Getting Started with unRAID
- Hardware Compatibility; Crossflashing Controllers
- Improving unRAID Performance
- Kernel and File Versions
- Ransomware Resistance Methods
- Release Notes
- Replacing a Data Drive
- Shrink array
- Start Contributing
- The parity swap procedure
- Tips and Tweaks
- Understanding SMART Reports
- Unofficial Documentation
- UnRAID Manual 6
- unRAID Plugins for V6
- UnRAID Topical Index - contains Linux reference and SMART reference
- Upgrading to UnRAID v6
- 64 bit Compatibility
- Best of the Forums
- Building a custom kernel
- Console commands for hard drives, networking, system management, files and folders
- Files on the unRAID flash drive
- Firmware upgrades
- Migrating from unRAID 4.7 to unRAID 5.0
- UnRAID Add Ons
- UnRAID Bug Tracking
- UnRAID5 Plugins, UnRAID Plugins, Plugins (contains a snapshot of an earlier UnRAID Plugins page)
- USB Flash Drive Preparation
- User Benchmarks
- Bash manual
- Libata error messages
- ATA errors and exceptions
- libATA Developer's Guide
- http://ata.wiki.kernel.org/index.php/Main_Page - Linux ATA wiki
- https://ata.wiki.kernel.org/index.php/SATA_hardware_features - features and Linux drivers for various SATA controllers
- Matching Linux ata numbers to the device names
- SATA 3Gb/s vs. 6Gb/s Cable Performance
- http://kerneltrap.org/mailarchive/linux-kernel/2007/4/3/72887 - Lower HD transfer rate (on WD drives) with NCQ enabled
- IO Schedulers - anticipatory deadline cfq noop
- APCUPSD User Manual
- Minimizing Hard Disk Drive Failure and Data Loss - (Wikibooks)
- How To Backup Operating Systems- (Wikibooks)
- Prolonging Life of Hard Drive
- A simple intro to sector structure and errors - UNC, IDNF, AMNF, etc
- http://www.myharddrivedied.com/presentations_whitepaper.html - comprehensive intro to hard drive mechanics, structures, and errors (sector errors at about 45% down)
- SATA Storage Technology - pdf file (MindShare ebook)
- The challenges of testing SATA - dispar, crc, 10b8b
- Hack 95. Repair and Recover ReiserFS Filesystems
- use -S option (eg. reiserfsck --rebuild-tree -S /dev/hda2) to Scan entire disk
- Hack 96. Piece Together Data from the lost+found
- Hack 100. Recover Lost Files and Perform Forensic Analysis
- http://www.namesys.com/ - home of ReiserFS
- Graffiti Networks
- Graffiti Networks - unRAID
- User talk:Iceheart - anti-spam regex, like our spammer
- Bad block HOWTO - instructions for both zeroing a bad block and forcing a remap, and determining what file contains the bad sector
- FAQ entry about USB - deals with accessing SMART info from some USB drives. Brian may want to try the '[b]-d usbcypress[/b]' option on the flash drive, and see if there is any SMART info for it (requires smartctl v5.37 or higher)
- Can we believe S.M.A.R.T. ?
- This smartmontools FAQ question, and the following one too, deal with uncorrectable sectors on a drive, and remapping sectors - rather interesting.
My ATA drive is failing its self-tests, but its SMART health status is 'PASS'. What's going on?
If your ATA drive supports self-tests, you should run them on a regular basis, for example one per week:
smartctl -t long /dev/hd?
After the test has completed, you should examine the results with:
smartctl -l selftest /dev/hd?
If the drive fails a self-test, but still has 'PASS' SMART health status, this usually means that there is a corrupted (uncorrectable=UNC) sector on the disk. This means that the ECC data stored at that sector is not consistent with the user data stored at that sector, and an attempt to read the sector fails with a UNC error. This can be a one-time transient effect: a sudden power failure while the disk was writing to the sector corrupted the ECC code or data, but the sector could correctly store new data. Or it can be a permanent effect: the magnetic media has been damaged by a bit of dust, and the sector could not correctly store new data.
If the disk can read the sector of data a single time, and the damage is permanent, not transient, then the disk firmware will mark the sector as 'bad' and allocate a spare sector to replace it. But if the disk can't read the sector even once, then it won't reallocate the sector, in hopes of being able, at some time in the future, to read the data from it. A write to an unreadable (corrupted) sector will fix the problem. If the damage is transient, then new consistent data will be written to the sector. If the damage is permanent, then the write will force sector reallocation. Please see Bad block HOWTO for instructions about how to force this sector to reallocate (Linux only).
The disk still has passing health status because the firmware has not found other signs of trouble, such as a failing servo.
Such disks can often be repaired by using the disk manufacturer's 'disk evaluation and repair' utility. Beware: this may force reallocation of the lost sector and thus corrupt or destroy any file system on the disk. See Bad block HOWTO for generic Linux instructions.
smartd is warning that my ATA disk has unreadable or uncorrectable or pending sectors. What's going on?
Disk drives store data in blocks (sectors) of 512 bytes. Each 512 bytes has additional bytes appended to it (usually 40 to 60) which are used internally by the disk firmware for error checking/detection and correction. These are called ECC bytes.
Sometimes the data in a sector gets corrupted. This can happen because a speck of dust scratched the disk, or because the disk was powered down while writing data to that sector, or for other reasons. Usually the ECC bytes can be used to correct the corrupted data. However if the ECC bytes are inconsistent or can't be used to correct the bad data, then the 512 bytes of data are lost. Such a sector is called unreadable or uncorrectable.
If your disk has an unreadable sector, this means that some of your data can't be retrieved. You can force the disk to replace the unreadable sector with a spare good sector, but only at the price of losing the 512 bytes of data forever.
Disks with uncorrectable sectors can often be repaired by using the disk manufacturer's 'disk evaluation and repair' utility (see previous FAQ entry). Beware: this may force reallocation of the lost sector and thus corrupt or destroy any file system on the disk. See Bad block HOWTO for generic Linux instructions.
Normally when an uncorrectable sector is found, the disk puts this onto a 'pending sector list' to indicate that it should be replaced with a spare good sector. However this replacement won't take place until either the disk can read the data on the bad sector, or is commanded to write new data to that bad sector.
- I would like to give credit where credit is due, and that is to parsec and gang, who first put the wiki wheels in motion, in this thread. It would sure be good to see those guys back here, participating in what they started. Perhaps they are too much like me, lots of intensity and interest at the beginning, then burn out.
- "Remove the manual from website and port to wiki" - good reading!
- Early top page
- Current top page
Temp holding area
- Swap file and swapon
- TCP tweak
- IDE Cable Advice especially here and here
- Some IDE cable recommendations
- Long IDE Cables
- Snug the cables
- Wiring network cable connectors
- Avoid emulation mode in CMOS SATA settings
- Enhanced SATA in CMOS SATA settings
- Cable weirdness - round = bad, flat = good
- 80-Conductor IDE Cables (external link and pic)
- "Clicking" drive, how to tell which one - especially this post
- Power Supply Myths (external link)
- Data recovery experience - A great write-up, mentions SpinRite and HDD Regenerator
- More IDE drive troubleshooting
- Troubleshooting sync errors especially here
- Using the power button for clean shutdown
- External Links, unRAID Reviews, and Builds
- ---avsforum initial thread
- ---avsforum builds with unRAID
Rob's Alternative unRAID Wiki start page
unRAID Server is a Network Attached Storage server operating system that boots from a USB Flash device and specifically designed for digital media storage.
For a more detailed introduction see the Overview page.
- Official unRAID Site:
- Official unRAID Support Forum:
- Official unRAID Software Download:
- Troubleshooting Guide
- Special:Recentchanges to this documentation
This wiki contains two types of content, official and user contributed documentation. All users are encouraged to document any information they believe relevant in the User Contributed section of this wiki. Even the most trivial detail will likely help other users with their problems.
|Written and proofed by the unRAID developers to ensure their integrity|
|Should be considered accurate and up to date (except during periods of beta releases)|
|Should be considered reflective of the normal use of the unRAID system|
|Should be your first port of call when learning to install and operate unRAID|
- Official documentation of the current version
- Frequently asked questions and answers.
|User Contributed Content|
|Because User Contributed Content is written and proofed by the unRAID user community, it may be less accurate|
|It may diverge from normal unRAID usage, and show you how to add non-standard functionality|
|It can show you how to enhance unRAID, add extra components, or improve existing ones|
|When using unofficial documentation, it is prudent to apply common sense as details may be incorrect|
- Troubleshooting - Problems with your unRAID system? Start here
- FAQ - Questions? If you don't find it in the FAQ, why not add it yourself
- Hardware Compatibility - Are your motherboard, networking, and disk controllers compatible?
- How-To's - Assorted How-To's written by expert users to help other users
- UnRAID Add Ons - Great user-written scripts to make unRAID life easier, or add functionality
- Best of the Forums - Categorized links to useful posts from the unRAID forums
- unRAID Support Forums - The unRAID forums are a great source of help, for searching, for asking, and for helping others
- User Benchmarks - Wondering how your system compares with others?
The content of this wiki is, as a whole or partly, created and edited by the users, and Lime-Technology is not responsible nor liable for the content.