Re: OT: silent data corruption reading from hard drives
flat view
From: Roberto Spadim <hidden>
Date: 2012-08-02 17:22:01
yes, that´s what i know too the point is develop a algorithm to make this in block level like a md device it write to disk and check if it was write ok it read from disk and check parity, if it´s wrong read again, after X times reading wrong report it as a badblock (now a silent corruption becomes a well know badblock disk corruption) i think that´s all... just need someone to implement it, some ideas: // create: mdadm --create /dev/md0 --level=integrity /dev/sda1 // check: echo "check" > /sys/block/md0/md/sync_action // repair: (like harddisks badblock recovery, mark the block as badblock, and it will never be used) echo "repair" > /sys/block/md0/md/sync_action when using it with raid1 raid10 or any other mirror mdadm device, the device with silent corruption can be reported (checksum don´t match data) as badblock (mdadm have news features to deal with badblocks...) the disk with badblock will be ignored and read will be done in next good disk... we could use a md5 checksum (32bits?! - 4 bytes) and data with less information, example today block is 512bytes.. change it to 508bytes of data + 4 bytes of checksum i think that´s all... 2012/8/2 Jeff Johnson [off-list ref]:
The only ways I know of to currently detect/repair silent data corruption are via the use of T10-DIF on SAS drives with 520-byte sectors and embedded per block CRCs (bytes 513-520) or via a patented algorithm used in a commercial Linux software RAID product (www.streamscale.com). Neither approach is cost effective for small or personal use RAID applications. On 8/2/12 10:04 AM, Roberto Spadim wrote:quoted
well i think the integrity is know, but it愀 not fully needed since the security isn愒 a problem we can buy secure sata/sas controlers/disks the main problem will be in some days when we are using SoC systems and we only have USB to connect a harddrive... maybe when this become more popular we will see a development of a module to have data integrity (silient corruption detection and maybe repair)-- ------------------------------ Jeff Johnson Manager Aeon Computing jeff.johnson@aeoncomputing.com www.aeoncomputing.com t: 858-412-3810 x101 f: 858-412-3845 m: 619-204-9061 /* New Address */ 4170 Morena Boulevard, Suite D - San Diego, CA 92117 -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
-- Roberto Spadim Spadim Technology / SPAEmpresarial -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html