- Sep 4, 2014
Anybody seen the 8TB Seagate Archive HDD? Model #: ST8000AS0002 to be specific. Is it viable to use in FreeNAS? I'd like to get 5 for my machine but I'm unsure if it would be recommended or not for FreeNAS.
My understanding is they use a similar strategy to SSDs, where they just write a new block instead of updating the old one, and eventually garbage collect it. Suffice to say Seagate engineers know a lot more about the system than any of us do, so I wouldn't put it out on a "theoretical" basis. That said, as with any new technology, proper testing is in order.Those drives are SMR. Without special filesystem support (absent in ZFS) they may be quite slow on random write/rewrite patterns. I had no chance to test them in practice, but from theoretical knowledge I would avoid them, if possible.
.. is that a typo? I don't see how an 8 MiB/s drive could even be released.it is not just a new block, the drive has to complete rewrite some "circles" on the disk. I had the original seagate archive 8tb (without v2): sequential reading was as fast as 8MB/sec (disk has been completely rewritten a couple of times, freespace reduced to 50%, but just ext4) I did not do any further tests
I would not be so surprised. Unlike SSDs, HDDs has huge seek time. Implementing SSD-like write strategy and later garbage collection may turn linear read into random one, for which 8MB/s is not really surprising... is that a typo? I don't see how an 8 MiB/s drive could even be released.
freenas smartd: Device: /dev/da23 [SAT], CHECK POWER STATUS returned 129, not ATA compliant, ignoring -n Directive
Maybe we shouldn't really be using drives without TLER/ERC/SCT in FreeNAS machines, but is there any good reason why FreeNAS itself couldn't have an option to wait a few seconds before dropping an apparently unresponsive drive from a vdev? I.e., do in FreeNAS what those other technologies do within the drive itself?That is not error correction. That is error recovery. All hard drives have their own error correction via ECC. ;)