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On Sun, May 3, 2020 at 1:44 AM Caveman Al Toraboran |
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<toraboracaveman@××××××××××.com> wrote: |
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> |
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> * RAID 1: fails to satisfy points (1) and (3)... |
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> this leaves me with RAID 10 |
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Two things: |
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1. RAID 10 doesn't satisfy point 1 (read and write performance are |
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identical). No RAID implementation I'm aware of does. |
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2. Some RAID1 implementations can satisfy point 3 (expandability to |
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additional space and replication multiplicities), particular when |
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combined with LVM. |
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I'd stop and think about your requirements a bit. You seem really |
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concerned about having identical read and write performance. RAID |
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implementations all have their pros in cons both in comparison with |
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each other, in comparison with non-RAID, and in comparison between |
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read and write within any particular RAID implementation. |
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I don't think you should focus so much on whether read=write in your |
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RAID. I'd focus more on whether read and write both meet your |
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requirements. |
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And on that note, what are your requirements? You haven't mentioned |
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what you plan to store on it or how this data will be stored or |
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accessed. It is hard to say whether any design will meet your |
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performance requirements when you haven't provided any, other than a |
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fairly arbitrary read=write one. |
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In general most RAID1 implementations aren't going to lag regular |
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non-RAID disk by much and will often exceed it (especially for |
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reading). I'm not saying RAID1 is the best option for you - I'm just |
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suggesting that you don't toss it out just because it reads faster |
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than it writes, especially in favor of RAID 10 which also reads faster |
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than it writes but has the additional caveat that small writes may |
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necessitate an additional read before write. |
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Not knowing your requirements it is hard to make more specific |
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recommendations but I'd also consider ZFS and distributed filesystems. |
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They have some pros and cons around flexibility and if you're |
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operating at a small scale - it might not be appropriate for your use |
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case, but you should consider them. |
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-- |
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Rich |
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