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On 16/05/2014 13:14, covici@××××××××××.com wrote: |
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> Alan McKinnon <alan.mckinnon@×××××.com> wrote: |
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> |
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>> On 16/05/2014 12:04, Canek Peláez Valdés wrote: |
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>>> Whatever gets rid of LVM is good on my book. I've never understood why |
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>>> people uses it, and in my experience it only brings headaches. |
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>>> Besides, I've heard from many people that btrfs is the way to go in |
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>>> the future. I'm not ready to make the change yet, but I will at some |
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>>> point. |
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>> |
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>> |
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>> LVM is an excellent solution for what it was designed to do, which is to |
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>> deal with stuff like this: |
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>> |
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>> Oops. I misjudged how big /var/log needed to be and now I need to add |
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>> 50G to that partition. But it's sda6 and I have up to sda8. Arggghhhhh! |
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>> Now I need 5 hour downtime to play 15-pieces with fdisk. |
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>> |
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>> LVM makes that 2 commands and 12 seconds. Yes, it's a bit complex and |
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>> you have to hold the PV/VG/LV model in your head, but it also *fixes* |
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>> the issue with rigid MSDOS partition style. |
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>> |
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>> Modern filesystems like ZFS and btrfs sidestep the need for LVM in a |
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>> really elegant and wonderful way, none of which changes the fact that |
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>> ZFS/btrfs weren't around when LVM was first coded. |
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> |
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> So is btrfs ready for production -- all the tools work, etc. to the |
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> level that the ext2/3/4 work? Also, what kernel do you need for this to |
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> function -- and last question, how to convert an lvm volume to btrfs, or |
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> do you just have to make some space somewhere and copy the files? |
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> |
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> So far, I have liked lvm, what's the advantage of btrfs over lvm? |
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I don't have enough experience with btrfs to answer, but I believe it's |
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much like ZFS in many ways. So here goes: |
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ZFS dispenses with the entire concept of partitions and rigidly |
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allocated areas of storage on a disk. All you really have is "storage". |
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You can divide it up into chunks and sections that look and feel like |
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volumes and partitions but that is not how it's implemented. You don't |
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create a 50G partition for logs, you tell the system to give you 50G of |
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space you will put logs in. And that "space" is something you can mount, |
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and apply permissions and quotas to. |
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It's a lot like having the best parts of partitions and directories in |
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one unit with none of the rigidity and downsides, and the whole lot is |
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done in a virtual manner by software. |
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|
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You can drop the entire hierarchy of disk/partition/pv/vg/lv/fs right |
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out of your head with these new modern systems, and just not ever have |
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to deal with that complexity at all. |
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|
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-- |
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Alan McKinnon |
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alan.mckinnon@×××××.com |