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On Tue, Mar 17, 2020 at 1:59 AM <tuxic@××××××.de> wrote: |
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> |
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> The HD will contain the whole system including the complete root |
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> filesustem. Updateing, installing via Gentoo tools will run using |
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> the HD. If that process has ended, I will rsync the HD based root |
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> fileystem to the SSD. |
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> ... |
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|
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I'll go ahead and write one consolidated reply to a couple of points |
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raised in these two threads to save everybody emails. |
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|
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First, I'll echo what was said about this being probably an |
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overly-complex solution to the problem. I think you'll spend more |
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time dealing with this than with any SSD failure issues. |
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|
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Next, in general you tend to get what you pay for. With SSDs if |
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you're getting that bargain 512GB drive for $15 when all the |
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comparable drives are $70, and it was made by some company you've |
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never heard of, chances are that you're missing something. I'm not |
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saying you need to go buy that 150% more expensive "signature edition" |
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drive or whatever, though it might very well have some feature that |
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justifies its price. Just be wary if things that look too good to be |
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true. If you buy a reputable brand that is marketed for your intended |
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use chances are you're getting something decent, even if you're paying |
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10% more. If you really know what you're doing you can certainly use |
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research to save money by critically evaluating your options. |
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|
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Finally, ALL DRIVES FAIL. It doesn't matter what the underlying |
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storage technology is. I've seen hard drives fail in less than a |
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year, with the warranty replacement drive failing less than a year |
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after that. I think next warranty replacement (still in the original |
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warranty period) lasted 5+ years of near-continuous use. The typical |
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failure modes of hard drives and solid state storage are different, |
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but they all fail. You can't perfectly predict WHEN they will fail |
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either. Most drives have SMART and sometimes it can detect failure |
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conditions before failure, but not always. |
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|
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What will you do when your brand new drive fails 3 weeks after you buy |
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it? If you don't have an answer that doesn't involve you losing stuff |
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you don't want to lose, or having downtime you don't want to have, |
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then you need to re-evaluate your approach. Backups and RAID are the |
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obvious solutions - with backup generally being the more reliable |
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solution to data loss, and RAID being the more reliable solution to |
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downtime, but with them both having some overlap. |
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|
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Here is what I've done: |
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1. Preferred solution to SSD failure and associated downtime is |
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RAID+backups. The most important stuff is backed up to the cloud, |
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encrypted. With SSDs I usually do a full backup to hard drives since |
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that is fairly inexpensive given their relative capacities. I'm using |
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ZFS mirroring as my RAID-like solution right now, and I use |
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ZFS-send/receive to do hourly backups that are very low overhead. |
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|
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2. If I'm too cheap to use RAID on a host then I just do the hourly |
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ZFS remote snapshots - that is a good solution on hosts where downtime |
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doesn't matter, because I can just get a new drive and restore the |
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snapshot and I'm back in business after a day or two, accepting a one |
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hour recovery point objective. |
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|
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You can of course use rsync as well. |
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|
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For rsync-based backups I recommend rsnapshot, in portage. |
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For zfs remote snapshots I have switched to zfs_autobackup: |
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https://github.com/psy0rz/zfs_autobackup/blob/master/README.md |
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|
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-- |
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Rich |