Category Archives: Uncategorized

btier-1.2.2 : Things that have changed

Introduction: It has been a while since I updated this blog about btier development. At a slow but steady pace I am however still fixing bugs and adding features. This article will explain what has changed as well as what … Continue reading

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btier-1.1.2 has been released

This version of btier seems to be very stable indeed. One of the problems that has now been solved was that btier could deadlock on high vfs cache pressure. Mostly when btier was not used with writethrough enabled on a … Continue reading

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BTIER-1.0.0 stable has been released

For some time people have been using btier in production. Some even use complex configurations that stack drbd and Oracle on top of btier. The good news is that even heavy users have not reported problems with btier. Therefore the … Continue reading

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btier-0.9.9.9-3 has been released

This release solves a bug that can lead to loss of data when btier is used with SSD’s and a recent kernel that supports discard / trim. Upgrading is highly recommended.

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Btier-0.9.9.9-1 has been released

This release dramatically improves random read performance. This has been achieved by introducing a thread pool and implementing aio for random reads. The performance of the 0.9.9.9 release was: seq_read : io=12288MB, bw=501371KB/s, iops=125342 , runt= 25097msec rnd_read : io=2985.3MB, … Continue reading

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TIER has been renamed to BTIER

What’s in a name TIER has been renamed to BTIER to improve the relevance of results returned by search engines. BTIER current status The btier code is now at 0.9.9.2 and I hope to release a stable 1.0 version within … Continue reading

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TIER-0.4.3 has been released

Introduction This version of TIER comes with a significant number of changes. The meta data has changed to support resizing of the TIER device. Therefore this version of TIER is not compatible with previous releases. New features This version of … Continue reading

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TIER-0.2.3 is available for download

This release of tier makes it possible to disable or enable data migration via sysfs. To disable migration: echo 1>/sys/block/tiera/tier/disable_migration To enable migration: echo 0>/sys/block/tiera/tier/disable_migration When migration is re-enabled the migration process will immediately wake up and start. This feature … Continue reading

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TIER OPTIMIZATION EFFECTS

How TIER works Tier is a Linux kernel block device that aggregates multiple devices of different nature into one virtual block device. The idea is to combine ( expensive ) fast and ( affordable ) slow devices to build a … Continue reading

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TIER-0.2.0 has been released

Tier-0.2.0 adds crash recovery and some bug fixes. A brief benchmark of tier, flashcache and bcache with fio shows these results: flashcache read : io=16635MB, bw=56778KB/s, iops=14194 , runt=300017msec read : io=872528KB, bw=2908.4KB/s, iops=727 , runt=300007msec write: io=8237.5MB, bw=28117KB/s, iops=7029 … Continue reading

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