Hot answers tagged

16

Re-reading Google's paper on the subject, "Failure Trends in a Large Disk Drive Population", I think I can safely say that Adam's answer is incorrect. In their analysis of an extremely massive population of drives, roughly 9% had non-zero reallocation counts. The telling quote is this: After their first reallocation, drives are over 14 times more ...


14

You don't. You go buy another disk to replace it unless you just really like losing data.


13

Drives, like most components, have a bathtub curve failure rate. They fail a lot in the beginning, have a relatively low failure rate in the middle, and then fail a lot as they reach the end of their life. Just as the whole drive follows this curve, particular areas of the disk will also follow this curve. You'll see a lot of sector re-allocations in the ...


10

Like I pointed out in my other answer, every modern hard drive has remapping space available (because especially at today's disk densities, no drive platter will be perfect - there will always be a few defects that the drive has to remap around, even on brand-new-never-been-used-came-off-the-assembly-line-into-my-hands drives). Because of this, ...


9

5 Reallocated_Sector_Ct 0x0033 100 100 005 Pre-fail Always - 87 <<<=== This is generally the count of how many bad sectors have already been added to the grown defects list that the drive keeps track of internally. NOTE: modern hard drives only remap sectors when a write occurs, so there will be a lot of cases where this attribute's raw ...


8

I'd like to thank you for the advice and share some of the details that I've got from experiments. In short, there is no easy way to get the list of reallocated sectors and even statistical methods of mapping the disk are heavily encumbered by the need to play against the logic of the firmware. To test the drive I ran badblocks -wv with the default ...


8

As described in the Bad Blocks Howto, find the partition which contain the bad block and calculate the sector offset inside the partition. Suppose that the partition is /dev/sda3, and it is an LVM PV. Determine the sector offset of the first PE: pvs -o pe_start --units s /dev/sda3 Subtract this offset from the bad sector offset to get the sector offset ...


7

I know you have an NTFS FS, and run windows on that FS. I don't know if you "could" boot a live Linux to work on that driver or not. If you can boot Linux from CD or USB, you can use ntfsprogs. look at - ntfscluster ntfsinfo I believe ntfscluster tell you what file a particular cluster stores. I hope this puts you in the right direction.


7

The NAND flash chips have some built-in mechanisms to detect failures on write and erase operations, and will alert the controller if one fails. In this case, the controller can either try again, or treat that block as bad and map it out of its wear-leveling algorithm. Each page in the NAND device also has a spare area alongside the main data area, which ...


7

Based on this answer and this answer in How do I easily repair a single unreadable block on a Linux disk?, you want to use hdparm to write to the sector. Assuming /dev/hda is your device and 48059863 is the LBA of the sector: hdparm --write-sector 48059863 /dev/sda That will blow away whatever data is in that sector. You'll need to add ...


7

Think about what you're asking... "Which of these tools is going to give me the best result on a disk of questionable health?" If the disk is this unhealthy and reporting errors from either of these tools, you should not use it. Neither S.M.A.R.T. nor badblocks is capable of detective every disk failure condition, but as a general rule, errors are bad. ...


6

I have recently found out that there is a kernel parameter (to provide at boot, in grub config for example) memmap=[ammount]M$[startlocation]M You can supply it many times to lock out parts of the memory. eg. memmap=3M$217M locks out megabytes from 217 to 219


6

The best thing you can do is get the disks replaced. The cost of disks won't weigh up against the cost of the cluster being down and your amount of work time being put in to fix the bad blocks. So even without a budget I would seriously try to convince your management.


6

Not easily. the sector reallocation happens inside the drive (which is why it's reported to you by SMART) -- your filesystem has no clue it's happening. As far as it's concerned sector 12345 is still sector 12345, that's what it asks the drive for. Internally the drive knows 12345 is now 67890 and returns the contents of the remapped sector. The only way I ...


5

This is SMART counter. Reallocated sectors are not exposed to the software. Physically, all drives have spare space reserve for reallocation, so, HDD is internally doing all the things, process is transparent to the outside world. While reallocated sector count is low enough - you don't have to worry about it, performance decrease won't be significant. ...


4

If for whatever reason you prefer to try to clear those bad sectors, and you do not care about the existing contents of a drive, the below shell snippet may help. I tested this on an older Seagate Barracuda drive that is well past its warranty anyway. It might not work right with other drive models or manufacturers, but it should put you on the right path if ...


4

I have to disagree with voretaq7 — SMART is not magic. When you have a drive and one of it's sectors goes bad, you'll not be able to read data from it anymore. So it is perfectly possible to have an unreadable file on a modern disk drive. SMART would mark this unreadable sector as "Current Pending" and "Offline Uncorrectable" when it would be first accessed ...


4

Depends. In daily business, your hard disk does write a checksum and some ECC information for every sector being written, and verifies this data during a read operation. If the error is small enough (e.g. a flipped bit or other minor errors) to be covered by your hard disk's ECC capabilities, your hard disk may recover from this on its own. The corrected ...


4

The snapshot is not corrupted. The filesystem that the snapshot contains is corrupted. There's a difference. The filesystem in a snapshot can be corrupted if you take the snapshot while the filesystem is in the middle of writing data. This can happen when only some of a all-or-nothing group of blocks were written when the snapshot was initiated. ...


3

If the drive is still under warranty, you can return it to the manufacturer via their RMA process for a free replacement, after sanitizing it first. (Secure Erase will wipe the entire drive, including reallocated or otherwise inaccessible sectors.) (I'm quite surprised nobody suggested this.) Otherwise, you do what @SpacemanSpiff said and buy a new drive.


3

If you have business data that is worth less than the cost of the drive then use them for that, if not then throw them away or give them to people from the department who understand the risks. Contact the manufacturer and see if they offer recycling.


3

Smart records a large number of values on the disk. For each value there is a limit before errors are reported. If you are getting smart errors your disk is most likely in a bad shape, but smart is not guaranteed to give a warning. Some types of abuse (starting and shutting down the disk very often) can give early smart errors. I don't know what interface ...


3

Different drives probably have different parameters. On a drive that I last checked that was a 1TB enterprise series disk from one vendor there were 2048 reserved sectors for reallocation. You can estimate the number of reserved sectors looking in the S.M.A.R.T. report on a drive that has got a nonzero number of reallocated sectors. Consider a report on a ...


3

There used to be the "BadMEM" patch for Linux, however it would take a bit of effort to upgrade it to a current keernel. http://badmem.sourceforge.net/docu/BadMEM-HOWTO.html


3

Off hand, try doing a disk dump of the dying drive to a healthy drive, and then add the healthy drive to the array.


3

This is just plain old filesystem corruption. You didn't give enough information about your environment to make an educated guess as to what happened, but the most common causes I've seen are: Not installing updates. Old kernels, especially on EL5 and older versions, have many filesystem related bugs which have been fixed and updates pushed. If you are ...


3

Good answers to this question are http://superuser.com/a/693065 http://superuser.com/a/693064 Contrary to other answers I find badblocks not outdated but a very useful tool. Once I upgraded my pc with a new hard drive and it started running unstable. It took me quite a while to realize thanks to badblocks that the disk surface had defects. Since then I ...


3

That's a lot to process... But a few things jump out at me. Your kernel version is: 2.6.18-164.15.1.el5 - That places your kernel revision at the EL5.4 level, or circa March 2010. I had persistent ext3 filesystem stability and corruption issues in EL5. Things weren't fully fixed until mid-2012. In my worst situation, I was working with a cloud ...


3

So, to figure this out I did the following. Take your block number, multiply by four and add one (130856866 * 4) + 1 = 523427465 This represents the sector reported as producing an I/O error. The block size being 2k, sectors being 512 bytes. The additional one extra accounts for the starting sector offset for the partition. To correlate with SMART, ...


2

You might want to run a S.M.A.R.T. long self-test, if the drive supports it. This may give you more information about the status of the drive. If your NAS cannot do this, and if you can pull the drive out or power down the NAS for a few hours, then you can do the long self-test with the hard disk plugged into another machine.



Only top voted, non community-wiki answers of a minimum length are eligible