ZFS is not magic – it needs backup and RAID (Restore it All Podcast #125)

This one will get you talking! Jody Bruchon, author of “ZFS won’t save you: fancy filesystem fanatics need to get a clue about bit rot (and RAID-5),”, joins us on the podcast. The blog post went viral, resulting in three times as many words in the comments as the original article had. We start with an explanation of bit rot, why it happens, and why ZFS won’t be able to fix all bit rot. (For more information on bit rot, check out Episode 111 of this podcast here: https://www.backupcentral.com/tape-drive-designer-schools-mr-backup-on-tape-restore-it-all-podcast-111/). Jody then explains how ZFS needs disk redundancy in order for its self-healing features to work, and how if you don’t have that, you’re going to need backup to repair a ZFS volume damaged by bit rot. (We also talk about how it’s possible for a bit to be flipped without being noticed – even with ZFS.) Jody’s main concern is that people talk about how ZFS can be used to repair data corruption – without explaining how you need RAID-Z (or something) to use those features. He also explains why he prefers RAID-5 or RAID-10 to RAID-6. We then discuss “shucking,” the practice of buying external drives and ripping the drive out of them – to save money.

Curtis (Mr. Backup) then gets into an argument with Jody about the merits of Blu-Ray vs disk vs tape as a backup medium. Jody has some good points, but Curtis was unconvinced.

If you want to read Jody Bruchon’s original article, you can do so here: https://www.jodybruchon.com/2017/03/07/zfs-wont-save-you-fancy-filesystem-fanatics-need-to-get-a-clue-about-bit-rot-and-raid-5/

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Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Evangelist at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.

How good is your backup system, really? (Restore it All Podcast #124)

Inspired by the article “How good is your backup, really?” by Sandra Vogel, we discuss how to evaluate and potentially redesign your backup system. We talk about different kinds of backup systems, and how that impacts how you evaluate them. We also talk about how important it is these days to ensure that your backups are impervious to ransomware. We also talk about the importance of including recovery testing in your evaluation, and what kinds of restores to test.

Here’s a link to the original article: https://www.itpro.com/server-storage/backup/357713/how-good-is-your-backup-really

----- Signature and Disclaimer -----

Written by W. Curtis Preston (@wcpreston). For those of you unfamiliar with my work, I've specialized in backup & recovery since 1993. I've written the O'Reilly books on backup and have worked with a number of native and commercial tools. I am now Chief Technical Evangelist at Druva, the leading provider of cloud-based data protection and data management tools for endpoints, infrastructure, and cloud applications. These posts reflect my own opinion and are not necessarily the opinion of my employer.