Comment 17 for bug 415888

Hi Colin,

So sorry for the delay - been up to my neck in work and kind of forgot about your request.
Anyway, attached is the sda folder - I hope it helps you.

As I said before tho, the problem doesn't appear to the balancing of the ssd itself.
The problem definitely resides with the implementation of the ext4 file system - does it use "unusual" s-ata commands that arent used by ext3? Any installation will work providing that ext3 is used.

ext3 will work for the ssd irrespective of whether or not the drive is correctly balanced.

The only advantage to defining the drive as -S 32 -H 8 is that all boundaries (apart from the first partition) will automatically be aligned on a 128k basis. As you will see from the attached files, my partition sda1 has been set up for the data to start at 1024, thereby negating the "first track" problem.

If extended partitions are used then the amount of space for the meta-data should be increased to 256k from the standard 192k in order to keep to the 128k multiple boundaries (thanks to Ted Tso for that one!).

I don't think that defining the raid stripe-width at 32 makes any difference, although I could be proven wrong on this point.

OCZ drives, I believe, use a stripe width of 512k rather than the 128k used by other manufacturers. For those drives the allignment would be slightly different.

For the reference books, I've also elected to mount the partitions using noatime in order to reduce the number of writes to the drive.
Also in /etc/laptop-mode/laptop-mode.conf it's possible to specify a spin down time of "1" since there are no delays with a ssd and no wear/tear involved in continually spinning up/down the drive. Also the amount of readahead has been set to 128k (the same as nolm) once again to reduce the amount of data read from the drive, hopefully thereby extending it's life slightly.

I really hope all this helps somehow.

If I can be of any further help to you, please don't hesitate to email.

Rachael