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LVM snapshot sizes.

linux-lvm Yaroslav Klyukin 2 participants 2 messages Jun 7, 2004

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I have created an LVM logical volume of the size arount 60G and formatted it with reiserfs. After that I put MySQL database onto this partition and made it a replicating slave. Using this configuration I took several LVM snapshots, 1G each.
It did not take long for these snapshots to overflow.

So here is the question:
Why would it take so fast to overflow an LVM snapshot?
In other words, what are the parameters, which affect snapshot fillups?
Is it possible, that journaling filesystem can contribute to the size of changing data on the logical volume, and would LVM2 be more efficient?

Thank you!

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#1 lore raw

Is your MySQL slave logging to the database partition? Replication binary logs can grow pretty quickly, which might be the reason your snapshot overflows.

You could try making your snapshot volumes larger.

Quoted 7 lines · On Mon, 07 Jun 2004 14:20:21 -0400 Yaroslav Klyukin…

I have created an LVM logical volume of the size arount 60G and formatted it with reiserfs. After that I put MySQL database onto this partition and made it a replicating slave.
Using this configuration I took several LVM snapshots, 1G each. It did not take long for these snapshots to overflow.

Quoted 17 lines

So here is the question:
Why would it take so fast to overflow an LVM snapshot?
In other words, what are the parameters, which affect snapshot fillups? Is it possible, that journaling filesystem can contribute to the size of changing data on the logical volume, and would LVM2 be more efficient?

Thank you!

Signature · 8 lines
Systems Administrator, NiuTech.
Cellular: (561) 843-1552
AIM: infiniteparticle
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