A question about error-checking

[silver]

i just recently learned i have to do this checking the hArd drive for errors thing. (You can tell i'm not very computer savvy) i followed the procedures on how to do it. After clicking the step: CHECK NOW. Iam then ask to select Disk Options: Automatically fix file system errors OR Scan for and attempt recovery of bad sectors. Which one do i check???? Can someone help me here???

[Hb_Kai]

Bad Sectors :

Problem

You think you have bad sectors on one or more hard disks (possibly in a RAID) that need to be repaired.

Symptoms of "bad sectors" include the following:

* read errors when accessing a standalone disk

* a RAID array entering degraded mode (because a single disk 'failed' and was subsequently removed by the operating system)

* a RAID array failing (because two or more disks 'failed')

* no main disk being mounted on boot-up (because the RAID has failed)

* intermittent data corruption, kernel panics, and/or reboots

One specific case that has come up a number of times is that the entire RAID will fail (and the system will reboot) when a RAID rebuild is occurring. On reboot, the RAID is no longer mounted.

Cause

Sometimes, a sector on a hard disk will fail in such a way that the data that was last written to it can no longer be read. When this occurs, the sector is marked as 'bad' and all subsequent read attempts will be met with an error. For stand-alone disks (i.e. a disk in 'legacy' mode), this can lead to kernel panics and reboots. Furthermore, the data is, most likely, lost forever.

For disks in a RAID, the effect of a bad sector on one disk is not too serious -- a 'read' to the RAID will access all of the disks, the system will detect the bad sector on one disk, inform the RAID subsystem, and the disk will be removed from the RAID array (which will then enter 'degraded' mode). No data loss will occur and the system will be able to continue to function.

When the RAID is in 'degraded' mode, it means that data is being properly read/written to the disks, but that there is no further redundancy. That is, if another disk fails, the RAID will cease to function. If, for example, a subsequent read to a different area of the RAID detects another bad sector on a different disk, that disk will also be removed from the RAID. At this point, the RAID will fail.

Note that when disks are removed from RAIDs, they are marked as 'bad' by the RAID system so that they cannot simply be added back into the RAID. Hence, if a RAID fails and the system reboots, the RAID will not and cannot be mounted. From the customer's perspective, their system (which was running in RAID degraded mode) locked up and rebooted, only to come up with no main disk available.

Another common scenario is that when a RAID rebuild is being performed, the system will lock up and reboot, only to come up with no main disk available. This occurs because, as the RAID is rebuilding, it reads every sector off of the 'degraded-mode' disks to rebuild the newly-added disk. If one of the 'degraded-mode' disks has a bad sector that has previously gone undetected, that disk will be removed from the RAID, the rebuild will be halted, and the RAID will fail.

Click first one basically unless you got any of them.

[silver]

Thank you HB :D

[CurlyWhirly]

As far as I know if you select "Automatically fix file system errors", it's a basic check that doesn't take long, however, if you select both options, then the checking can take several hours on a large hard drive.

[Dencandy]

As far as I know if you select "Automatically fix file system errors", it's a basic check that doesn't take long, however, if you select both options, then the checking can take several hours on a large hard drive.

True, but it does the most thorough job. The first option checks for file system errors and tries to repair them; but can't fix them all as some files (e.g. dll files) can only be repaired from the installation disk which requires the use of the scannow routine.

The second one will also check the disk itself, try to recover any data stored on bad sectors & mark those sectors as defective so they won't be used in future. That seems worthwhile if you HD is more than a couple of years old.

[CurlyWhirly]

As far as I know if you select "Automatically fix file system errors", it's a basic check that doesn't take long, however, if you select both options, then the checking can take several hours on a large hard drive.

True, but it does the most thorough job. The first option checks for file system errors and tries to repair them; but can't fix them all as some files (e.g. dll files) can only be repaired from the installation disk which requires the use of the scannow routine.

The second one will also check the disk itself, try to recover any data stored on bad sectors & mark those sectors as defective so they won't be used in future. That seems worthwhile if you HD is more than a couple of years old.

Agreed but should my hard drive ever need a thorough error check then I would prefer to use the manufacturers tool which in my case would be WD Diagnostics (Western Digital)

I don't know how the Windows version compares with it to be honest

[silver]

Okay. now i have a question about Local Disk H. Do i error check it, too?