ESXi 5 TRIM Support?

[tonybourke]

I noticed my data store says "Non-SSD", does that mean ESXi 5 has TRIM support? I'm not finding anything in the documentation, but that would be excellent.

[wdroush1]

I believe this is for identifying SSD drives for the new ESXi 5.0 SSD swap.

[mcowger]

Correct - its not about trim, its about use as local swap.

[Dave_Mishchenko]

I haven't seen any mention of TRIM support.  Storage identified as SSD can be used with the new swap to host cache feature - http://www.yellow-bricks.com/2011/08/18/swap-to-host-cache-aka-swap-to-ssd/.

[RParker]

Dave Mishchenko wrote:

I haven't seen any mention of TRIM support.  Storage identified as SSD can be used with the new swap to host cache feature - http://www.yellow-bricks.com/2011/08/18/swap-to-host-cache-aka-swap-to-ssd/.

In principle this seems like a waste, simply because using disks is not as fast as RAM.  However SSD drives are REALLY fast (enterprise class) and I wonder if RAM is much difference in speed.  I realize you still have to deal with a controller, so there will probably be some difference, and SWAP probably isn't the same as RAM even if they were equal response times, because the OS will give priority to RAM over SWAP (I am guessing).

Still it is better to use RAM rather than SWAP, and considering SSD drives are expensive it's better to simply upgrade the RAM in the long run...

[mcowger]

In principle this seems like a waste, simply because using disks is not as fast as RAM.  However SSD drives are REALLY fast (enterprise class) and I wonder if RAM is much difference in speed.  I realize you still have to deal with a controller, so there will probably be some difference, and SWAP probably isn't the same as RAM even if they were equal response times, because the OS will give priority to RAM over SWAP (I am guessing).

RAM is still an order of magnitude faster than SSD.

Still it is better to use RAM rather than SWAP, and considering SSD drives are expensive it's better to simply upgrade the RAM in the long run...

SSDs are still 10x cheaper per GB than RAM....

[RParker]

Matt wrote:

In principle this seems like a waste, simply because using disks is not as fast as RAM.  However SSD drives are REALLY fast (enterprise class) and I wonder if RAM is much difference in speed.  I realize you still have to deal with a controller, so there will probably be some difference, and SWAP probably isn't the same as RAM even if they were equal response times, because the OS will give priority to RAM over SWAP (I am guessing).

RAM is still an order of magnitude faster than SSD.

Still it is better to use RAM rather than SWAP, and considering SSD drives are expensive it's better to simply upgrade the RAM in the long run...

SSDs are still 10x cheaper per GB than RAM....

OH yeah I guess that's true.. a 64GB SSD is about $120.00.. no way you can find RAM that cheap..

[wdroush1]

RParker wrote:

Dave Mishchenko wrote:

I haven't seen any mention of TRIM support.  Storage identified as SSD can be used with the new swap to host cache feature - http://www.yellow-bricks.com/2011/08/18/swap-to-host-cache-aka-swap-to-ssd/.

In principle this seems like a waste, simply because using disks is not as fast as RAM.  However SSD drives are REALLY fast (enterprise class) and I wonder if RAM is much difference in speed.  I realize you still have to deal with a controller, so there will probably be some difference, and SWAP probably isn't the same as RAM even if they were equal response times, because the OS will give priority to RAM over SWAP (I am guessing).

Still it is better to use RAM rather than SWAP, and considering SSD drives are expensive it's better to simply upgrade the RAM in the long run...

RAM is immensely faster than SSDs

http://communities.vmware.com/message/1809643#1809643 (thanks J1mbo for crunching those numbers, 2nd time I've sourced this post!) note: hypertransport bandwidth is around 50GB/s, though that's theoretically, due to inter-processor communication I never know if this can be achieved.