SSD on Pro

mps wrote:
StephenB wrote: Also, I don't see a lot of value in using RAID with SSD. They don't have the same failure mechanisms as hard drives. Sizes also aren't aligned with hard drive sizes. I suspect your 512GB hard drives are actually 500 GB. Can you please elaborate on the problem with using SSDs in RAID? I'm using X-RAID2, which IIUC works with mixed-size drives and provides redundancy.

Assuming I am correct in thinking that your hard drive is 500 GB and your SSD is 512 GB, then you will probably have trouble simply inserting the SSD into the RAID array. With XRAID2, a new drive is either (a) >= the largest drive in the array or (b) exactly the same size as the drive it is replacing.

Also, I said I didn't see much value in SSD in RAID. A single SSD is faster than gigabit ethernet, so there is no performance gain in a RAID array of SSDs over jbod. With RAID-1 or RAID-5 you double the disk writes over jbod, with RAID-6 you triple the disk writes. And the writes to a consumer grade SSD are what limit its life. If all the SSDs are identical, and in the same array, then the writes should also nearly identical. So my guess is that they are even more likely to fail together than traditional drives, overwhelming RAID protection.

And with jbod, you can get trim to work more easily.

In your case, you are proposing a mix of SSD and hard drives. Your music files and directories will be partly on SSD and partly not. It won't be slower than your current setup, but it seems unlikely to be a giant step up either.

So if it were me, I'd back up the music, etc. and remove all the drives. Then install the two SSDs as jbod, load up some music, and see how it performs. If it works, then solve the trim problem, perhaps add in some the hard drives as a second RAID-1 volume and go from there. If it doesn't help, then power down, install all your old drives and you are back to where you are now.