SSD life in RAIDs

[shaithis]

Just took delivery of a couple of new SSDs and while doing the partition copying I was sat there thinking......and came to the conclusion that RAIDing SSDs in RAID 0, 3, 5 or 6 will actually increase their lifespan...and quite dramatically.

In RAID0, life duration due to write operations should be increased by the number of disks in the array. i.e. 2 disk will double their lifespan, 3 will triple etc. Due to the write being divided up and therefore each operation you preform causes less write changes on each disk.

The other modes will increase life by number of disks - number of parity disks....so disks in a 5 drive raid5 with 1 parity disk should last 4 times as long.

Combined with scaling much better then mechanical drives and the minimal differences in price/GB between different size models in a range, makes SSDs a prime candidate for RAIDing whenever possible.

[Terbinator]

I've always wondered about the above^

You can also decrease lack fo TRIM by creating a disk capacity smaller than actual drive size as the drives should automatically use the extra unused capacity as spare area.

[Jay]

I think this will depend on the size of the files your write to the disk

[jim]

Impression I've been getting is that life is so long it's not worth worrying about in the real world.

Not when hard drives can be so flimsy anyway.

[dirky]

The lack of trim just means that the drive needs to erase the cell before it writes to it; which in turn will "slow" it down (two actions instead of one). trim normally cleans these old cells in the background then the disk is idle, so they are ready to be written to without the need for the erase..

[kalniel]

Just took delivery of a couple of new SSDs and while doing the partition copying I was sat there thinking......and came to the conclusion that RAIDing SSDs in RAID 0, 3, 5 or 6 will actually increase their lifespan...and quite dramatically.

In RAID0, life duration due to write operations should be increased by the number of disks in the array. i.e. 2 disk will double their lifespan, 3 will triple etc. Due to the write being divided up and therefore each operation you preform causes less write changes on each disk.

The other modes will increase life by number of disks - number of parity disks....so disks in a 5 drive raid5 with 1 parity disk should last 4 times as long.

Combined with scaling much better then mechanical drives and the minimal differences in price/GB between different size models in a range, makes SSDs a prime candidate for RAIDing whenever possible.

Yes, precisely. Two other advantages are bypassing individual channel bandwidth limits and effective increasing of cache size - caching can be a key performance and lifespan factor if the controller needs to order operations.