Hi Marek, If you know the "parity algorithm" your RAID was created with, the RAID chunk size and the position in the array of each drive (all available with mdadm -D /dev/mdX), the location of each parity block is deterministic. The parity block itself doesn't contain a signature, it's just a XOR value. In light of this, if all your drives contained exclusively zeroes, the parity block would be indistinguishable from the data blocks. Check out http://www.accs.com/p_and_p/RAID/LinuxRAID.html which has some good information as to how the RAID 5 parity behaves. Regards, Ben. On Mon, Feb 19, 2018 at 2:42 AM, Marek <mlf.conv@xxxxxxxxx> wrote: > Is there a way to detect a parity block eg by signature or otherwise? > (when reading raid data and trying to destripe mdadm raid data) > > thanks, > Marek > -- > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html -- CONFIDENTIALITY This e-mail message and any attachments thereto, is intended only for use by the addressee(s) named herein and may contain legally privileged and/or confidential information. If you are not the intended recipient of this e-mail message, you are hereby notified that any dissemination, distribution or copying of this e-mail message, and any attachments thereto, is strictly prohibited. If you have received this e-mail message in error, please immediately notify the sender and permanently delete the original and any copies of this email and any prints thereof. ABSENT AN EXPRESS STATEMENT TO THE CONTRARY HEREINABOVE, THIS E-MAIL IS NOT INTENDED AS A SUBSTITUTE FOR A WRITING. Notwithstanding the Uniform Electronic Transactions Act or the applicability of any other law of similar substance and effect, absent an express statement to the contrary hereinabove, this e-mail message its contents, and any attachments hereto are not intended to represent an offer or acceptance to enter into a contract and are not otherwise intended to bind the sender, MPSTOR, or any other person or entity. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
