Running SSD’s in RAID can get very expensive very quickly.  A more cost effective solution is to have a disk RAID and use an SSD as a cache.  I’m not sure if any of these are production ready but all are worth watching:

• zfs-fuse – supports the ZFS L2ARC feature which can be used to setup an SSD as a cache for a ZFS pool.  Checksums SSD data and supports multiple devices.
  • ZIL and L2ARC cache questions
  • ZFS – zpool ARC cache plus L2ARC benchmarking
  • How stable is zfs-fuse 0.6.9 on Linux?
• bcache – a recent project for caching linux block devices. Currently only supports 1 cache device and offers no checksumming.
  • Bcache: Caching beyond just RAM
  • Want to use an SSD as cache? Now you can
• flashcache – created and released by and for facebook this at least seems to be in production. documentation is not great however.
  • Facebook releases Flashcache

It is not uncommon for people to have performance problems with the their virtual servers and chalk it up to virtualization as the problem instead of insufficient entropy.  Running a mail server or SSL web server are particularly vulnerable to virtual servers without much entropy.  I have noticed that my virtual servers have had a lot less entropy in the past 6 months or so.  I decided to revisit what simple and effective solutions exist to solve this problem.

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• Copy Without Formatting
• FlashBlock (there’s also this FlashBlock, not sure what the practical difference is)

MySQL Workbench 5.2.16 Beta 6 Available

The term search engine is particularly vague.  It can mean an online search engine, or it can mean software that provides something similar to the online search engines, or it can mean software that does fulltext indexing and querying.  I specifically wanted to find a tool that could be used to create a niche search engine without having to write the whole thing myself as a ruby on rails app.  Here’s what I found:

• mnoGoSearch – seems very actively maintained, packages present in Debian and Ubuntu, written in c
• DataparkSearch – seems fairly actively maintained, apparently a branch of mnoGoSearch, written in c
• Nutch – seems fairly actively maintained,written in java, built on top of Lucene

And that’s really it.  There is a product called ASPseek but it has long since been abandoned.  There is also ht://Dig but it has not been updated in years and is not really in the same league as the above.  So, at least for anyone trying to research this area there are not a whole lot options to try.

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I believe this is my 6th blog.  So far I have never taken the time to migrate articles from one to another and I am continuing that tradition.  Not so good for the internet perhaps but better for me to not have to take the time to get a migration right.  I may go back and report some of my older content as appropriate though.  I decided to use wordpress this time because I’m supporting some other wordpress users.  I haven’t been the biggest wordpress fan in the past but I’m willing to give it another try.