Greetings,
I am looking for real-world performance figures from somebody who has actually done this: how many SSD-based vdevs are needed in practice to write to an LTO-8 drive at full speed? Assuming reasonably-priced, good quality, consumer-grade SSDs, for example 4TB Samsung EVO 870. (Not using "enterprise grade" SSDs that cost thousands of dollars).
I would prefer not to have to go the pricey SSD route, but the PBS docs state that:
"LTO-8 tapes provide read/write speeds of up to 360 MB/s". "[Using HDDs] we measured a maximum rate of about 60MB/s to 100MB/s in practice".
If I got my math right, that would mean that 4-6 (HDD) vdevs would be required to keep the SAS cable full. Redundancy requires at least 3 drives per vdev, so I'd be looking at 3 HDDs * 4-6 vdevs = 12-18 HDDs minimum. That's more than my server has drive bays.
If you are writing backups to LTO-8 using PBS, please do let me know what you found works for you to write at full LTO-8 speed.
Big Thanks,
-- Lucky
I am looking for real-world performance figures from somebody who has actually done this: how many SSD-based vdevs are needed in practice to write to an LTO-8 drive at full speed? Assuming reasonably-priced, good quality, consumer-grade SSDs, for example 4TB Samsung EVO 870. (Not using "enterprise grade" SSDs that cost thousands of dollars).
I would prefer not to have to go the pricey SSD route, but the PBS docs state that:
"LTO-8 tapes provide read/write speeds of up to 360 MB/s". "[Using HDDs] we measured a maximum rate of about 60MB/s to 100MB/s in practice".
If I got my math right, that would mean that 4-6 (HDD) vdevs would be required to keep the SAS cable full. Redundancy requires at least 3 drives per vdev, so I'd be looking at 3 HDDs * 4-6 vdevs = 12-18 HDDs minimum. That's more than my server has drive bays.
If you are writing backups to LTO-8 using PBS, please do let me know what you found works for you to write at full LTO-8 speed.
Big Thanks,
-- Lucky