Verify Data

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This feature was added in release 1.41. It instructs the selected disk(s) to invoke the built-in SCSI verify function.  This function is built into most disk drives and runs very quickly with near-zero host overhead.  Feel free to use this on as many drives as you wish concurrently. (You must, however, run multiple instances of the software as the program will lock up until the current drive completes the process.


The -verify command is supported on SCSI, SAS, Fibre Channel disks under all operating systems.  It is also supported on ATA/SATA disk drives under Windows.  (If you have ATA or SATA disks on other operating systems, then check with us to see if this command is ported to your operating system.  


Benefits of running SCSI Verify Function

The -verify function runs inside of the drive firmware, so there is near-zero host overhead.
The -verify is the fastest technique possible for the disk drive to make sure that there are no bad disk blocks.  You can verify as many disks as your hosts can support concurrently.
Blocks go bad 24x7.  This command will tell you if you have any bad blocks, regardless of whether or not the block is being used by a file, before the operating system asks for the data.  Once you know where you have corruption, you can react accordingly.  Remember, if you have RAID5 and lose a disk drive, but have a bad block on a surviving disk, then you have 100% data loss for that chunk. Furthermore, some RAID controllers will fail a rebuild in this situation and you could very well be left with a RAID system that will not repair itself.



-verify -scrubv (the -scrubq makes output verbose so bad blocks and percent complete will be reported as the drive progresses).


Example - Verifying a SCSI Drive


smartmon-ux -verify -scrubv \\.\PhysicalDrive2

SMARTMon-UX [Release 1.41, Build  1-NOV-2009] - Copyright 2001-2009 SANtools(R), Inc.

Discovered HP 36.4G MAU3036NC S/N "KY010344" on \\.\PHYSICALDRIVE2 (Not Enabling SMART) [Bus/Port/ID.LUN=0/2/9.0](34732 MB)


Beginning SANtools  verify fitness test for HP 36.4G MAU3036NC at \\.\PHYSICALDRIVE2 (71132960 blocks, blocksize=512)


Test completed.


Read/Verify error summary:

Verify errors for HP 36.4G MAU3036NC at \\.\PHYSICALDRIVE2: No problems found.


Program Ended.


Example #2 - Verifying a SATA Drive

smartmon-ux -verify \\.\PhysicalDrive1

SMARTMon-UX [Release 1.41, Build  1-NOV-2009] - Copyright 2001-2009 SANtools(R), Inc.

Discovered Maxtor 6L100P0 S/N "L23MTW0G" on \\.\PhysicalDrive1 (SMART Enabled)

The current device temperature is:  39C (102F) degrees


Beginning SANtools read/verify test for Maxtor 6L100P0 at \\.\PhysicalDrive1 (195813072 blocks, blocksize=512)


Read/Verify error summary:

Event#   PowerOnMins   HexBlockNumber   State   Reassignment Status             AdditionalInfo

     0             -            16c0f   ERR     reassign failed, data invalid   Block 93184 ERR/DEV/STAT:

                                                                                00/F0/51 Error: DRDY, DSC, ERR

     1             -            219a7   ERR     reassign failed, data invalid   Block 137472 ERR/DEV/STAT:

                                                                                00/F0/51 Error: DRDY, DSC, ERR

     2             -            21a19   ERR     reassign failed, data invalid   Block 137728 ERR/DEV/STAT:

                                                                                00/F0/51 Error: DRDY, DSC, ERR


Program Ended.



Feature Notes:

The SATA disk has 3 bad blocks that are unreadable, while the SCSI disk reported no errors.
The test completed in 6 minutes on the 36GB SCSI disk, and 25 minutes on the SATA disk.
The SCSI disk used the additional -scrubv option which reported percent complete and estimated completion time as it progressed.