As I'm sure a number of users are wondering the performance/feedback before purchasing one of these Hybrid machines I thought I would enlighten and SAVE some of you.
Over the last week and a half I have been
frustratingly trying to improve the performance of SSDs within Linux - I have spent sleepless nights in astonishment as the secondary SATA drives outperform the SSDs in every sequential Read/Write situation I throw at them.
Don't get me wrong, the Random Read speeds and instant deleting (basically) is great:
/dev/md2:
Timing cached reads: 17052 MB in 2.00 seconds = 8533.87 MB/sec
Timing buffered disk reads: 1510 MB in 3.00 seconds = 502.69 MB/sec
/dev/md2:
Timing cached reads: 16706 MB in 2.00 seconds = 8360.14 MB/sec
Timing buffered disk reads: 1508 MB in 3.00 seconds = 502.50 MB/sec
/dev/md2:
Timing cached reads: 17112 MB in 2.00 seconds = 8563.66 MB/sec
Timing buffered disk reads: 1516 MB in 3.00 seconds = 504.70 MB/sec
After trying NUMEROUS Linux Distros in search of the latest and greatest (Unfortunately our FANTASTIC /sarcasm - OVH Rescue Mode doesn't allow for manually OS installation through debootstrap etc - more on this later) I ended up trailing Ubuntu Server 9.10 (also upgrade to Lucid), Debian 5 (updated to Squeeze) and BSD.
Reading numerous Forums/Articles across the internet I found numerous 'recommended' tips and tweaks which I have implemented, benchmark and tested with hardly any notice improvements. UNFORTUNATELY the last 2 and probably most
major ones we cannot do with OVH -
SSD Alignment and
Firmware updates.
A couple articles for OVH and users to read over:
1.
http://thunk.org/tytso/blog/2009/02/...se-block-size/
2.
http://www.ocztechnologyforum.com/fo...-and-alignment
As you can see from the first article
SSD Alignment seems EXTREMLY logical but with the way OVH has things setup there is
currently no way to align the SSDs (wiping them clean in the process) and re-installing the desired OS - we are UNABLE to boot onto the SATA (so as I could work with the SSDs in live mode), and we are unable to use 'debootstrap' or any other custom ways to install distros through Rescue Mode.
Short of me having to mathematically calculate what sized partition to create so I can throw the the first SSD into alignment which is LOL
Factor in I was just quoted
60-90 pounds for someone to throw an Intel .ISO in a cd-rom drive and update the SSDs is outrageous - this should be offered, these are brand new systems and are not cheap.
I have now tried EVERYTHING under the sun:
- Disabling 'atime' and 'diratime'
- Changing of Schedulers from CFQ to Noop to Deadline
- Disabling of Swap
- Moving Logs to temp RAMDisk
- ext2, ext3, ext4, xfs and newer FS (btfs etc)
- Addition of increase 'commit' intervals, disabling of 'barrier', enabling 'data=writeback'
- Kernel update to 2.6.33 (Which supports TRIM and various fixes for SSD HDDs - supposedly)
The list is endless - I've come to the end of my tether and now speaking to my Company to assign me a Windows 2008 Server key so as I can test Winblows to see if things improve (You linux gurus out there must realise for a AVID linux user as myself over the last 10 years to consider going to Windows is quite a HUGE step..).
I ask you all to be weary, and ask OVH to look into the issue of Alignment and Firmware updates as this 'new' and 'fast' SSD equipped Hybrid range are no better then a stock SATA based setup.
- OVHelp