Managed Disk Download Failed

[vdubgeek]

Attempting to download managed disk with AzureStorageExplorer 1.12. Transfer fails after several hours. Following error is logged:
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AzCopy failed to complete the transfer: %s

AzCopy error message: Transfer of https://md-ssd-qdtft2bkpfmq.blob.core.windows.net/s0w1jpgphj2w/abcd to \?\D:\AzureDownload\epicor02-c.vhd failed: Status: Failed, Error code: 0

AzCopy log file can be found at C:\Users\administrator.ALTAKINC.azcopy\417f7757-c57d-014f-7079-70e5aa70d5e5.log

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417f7757-c57d-014f-7079-70e5aa70d5e5.log

[MRayermannMSFT]

Hi @vdubgeek , it looks like the MD5 check failed:

2020/02/02 13:43:48 ERR: [P#0-T#0] DOWNLOADFAILED: https://md-ssd-qdtft2bkpfmq.blob.core.windows.net/s0w1jpgphj2w/abcd?si=cbc72cbf-9ef6-44ed-993d-50723914e18f&sig=-REDACTED-&sr=b&sv=2017-04-17 : 000 : the MD5 hash of the data, as we received it, did not match the expected value, as found in the Blob/File Service. This means that either there is a data integrity error OR another tool has failed to keep the stored hash up to date. When Checking MD5 hash. X-Ms-Request-Id: 

You can disable MD5 checking in Settings -> Transfers -> AzCopy -> Check MD5

Please let us know if that solves your problem.

[vdubgeek]

It seems like it would be a bad idea to disable the MD5 check, no? I tried downloading several different VHD files using the explorer, and each one failed with a similar error. What might be causing the MD5 checksum to fail?

[MRayermannMSFT]

@vdubgeek we just learned today that we (Storage Explorer) should not be putting an MD5 hash on disks when uploading them and that we shouldn't check it when downloading. VMs/the Managed Disks backend don't keep that MD5 up-to-date. So it should be safe to disable the MD5 check while downloading disks. We'll also disable checking/putting MD5 for disks in 1.13.0.

Did you originally upload your disk using Storage Explorer?

[vdubgeek]

Interesting, good to know that the managed disks md5 is not kept current. I feel much better disabling the MD5 check knowing that. Thank you for the update

[MRayermannMSFT]

Hey @vdubgeek, how did you originally create the disk? I just checked our code and we don't tell azcopy to set MD5 when uploading a disk. So I think it is important that we understand who originally put the MD5 on the disk's page blob.

Also, if you don't mind I need to leave this open for now as I do need to disable checking the md5 for disk download. I'll close this once I finish that work.

[MRayermannMSFT]

@vdubgeek , I need to move on from this issue. If you need any additional help please open a new issue. Thanks.