The default stripe breadth on a metadata storage pool is 256 blocks. However, this is way, way too high. Quantum recommends using a 16 or 64 block stripe breadth for metadata storage pools. If you have a relatively small volume with a small number of files then use 16 and if you have a larger environment with big files use 64. As with many things re: Xsan the tuning per environment is where you will get the biggest bang for your buck, but it is worth noting that no matter which way you go, this is a setting that should be changed on each deployment in order to keep with…
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Xsan: Small Files & AFP
Xsan can be used as the back end storage to provide front end network file share services for a Mac OS X environment. This isn’t to say that it will work like a charm without some fine tuning though. One of the most important tools you have in performance tuning any Xsan volume is the block size. As I’ve mentioned in the past, the stripe breadth multiplied by the block size should total out to about 1MB total. The stripe breadth on the storage pools is therefore going to need to be customized any time you change the block sizes for the volume. If you are using Xsan as a…
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Xsan: Block Sizes
All volumes have a block size. In Mac OS X you can see a block size by entering the following command (assuming disk0): sudo diskutil information 0 If you notice in the Total Size: field you’ll see the number of blocks followed by a block size. By default it is 512 bytes. One of the things that makes it possible to attain high performance from an Xsan volume is the ability for the block size to be customized. The general rule of thumb is that the Stripe Breadth and the Block size should multiply to equal 1MB. So if you have a block size of 256 then your stripe breadth…