Re: defragmentation on cache disk

From: <>
Date: Tue, 23 May 2000 20:20:35 +0100 (BST)


In the Squid FAQ 14.1 it says:
he UFS filesystem used by Solaris can't cope with the workload squid presents to it very well.
Sun suggest two solutions to this problem. One costs money, the other is free but may result in a loss
 of performance (although Sun do claim it shouldn't, given the already highly random nature of squid d
isk access).

The first is to buy a copy of VxFS, the Veritas Filesystem. This is an extent-based filesystem and it'
s capable of having online defragmentation performed on mounted filesystems. This costs money, however
 (VxFS is not very cheap!)

The second is to change certain parameters of the UFS filesystem. Unmount your cache filesystems and u
se tunefs to change optimization to "space" and to reduce the "minfree" value to 3-5% (under Solaris 2
.6 and higher, very large filesystems will almost certainly have a minfree of 2% already and you shoul
dn't increase this). You should be able to get fragmentation down to around 3% by doing this, with an
accompanied increase in the amount of space available.
If you use the minfree approach let me know how it goes as I have the same type of system as you
and I'm considering using minfree.

Received on Tue May 23 2000 - 13:24:21 MDT

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