Jump to content
Covecube Inc.
  • 0
HTWingNut

MISMATCH Checksum Hash Values with DrivePool

Question

After much angst, I realized that READ STRIPING can affect the calculated checksum hash value of a file. Turning off read striping enables consistent hash checksum values.

IS THERE ANY WAY TO DISABLE AND ENABLE READ STRIPING FROM COMMAND LINE?

I run a batch script for my backups every evening and recently added a hash check. It looks like I need to disable read striping otherwise hash checksum values are affected.

If  the read striping could be toggled from a command line, it could be turned off before backup and back on after backup. Otherwise I have to leave read-striping disabled if I want to use any kind of integrity check.

 

Share this post


Link to post
Share on other sites

2 answers to this question

Recommended Posts

  • 0

Ok, I will open a ticket.

Problem is it's not consistent and it's somewhat difficult to reproduce. It seems to happen more often with large files. I ended up with a few dozen files while getting checksum of over a couple hundred thousand files. This occurred with sha1 md5 blake2.

The strange thing is that if I get an SHA1 hash of a file on a known good drive (not in DrivePool), for simplicity say checksum equals "123456ab". If I copy that file to DrivePool and with read-striping off, hash equals "123456ab".  If I enable read striping and this anomaly occurs hash is now say "412453bf". But if I copy that file even with read-striping on to another external drive, the hash is equal to "123456ab". So it's not like the file changes. After turning off read-striping, I ran another checksum of all the files and everything was fine.

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Answer this question...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...

×
×
  • Create New...