Re: Zoned Commands ZBC/ZAC, Shingled SMR drives, ZFS

2015-03-24 Thread Shehbaz Jaffer
Hi, I was wondering what cost advantage do SMR drive provide as compared to normal CMR drive? 8TB SMR drive - $ 260 3TB CMR (Conventional Magnetic Recording drive) - $ 105 Is the 8TB SMR drive that you mentioned in another post on this mailing list host or drive managed? I was curious to know

Re: Zoned Commands ZBC/ZAC, Shingled SMR drives, ZFS

2015-03-24 Thread Dieter BSD
You can also find these drives inside the STDT8000100 external USB unit for a bit more at $300. It may or may not be the same. There are stories that it is difficult or impossible to talk directly to the drives in recent USB units without the usb-to-sata bridge. I have yet to find a

Re: Zoned Commands ZBC/ZAC, Shingled SMR drives, ZFS

2015-03-24 Thread InterNetX - Juergen Gotteswinter
The HGST He8 HDDs completed its rebuild in 19 hours and 46 minutes. The Seagate Archive HDDs completed their rebuild in 57 hours and 13 minutes this is ... a feature. right? Am 24.03.2015 um 18:05 schrieb Dale Kline: READ THE DOCUMENTATION THOROUGHLY on these SMR drives. There are serious

RE: Zoned Commands ZBC/ZAC, Shingled SMR drives, ZFS

2015-03-24 Thread Michael Jung
I understand there to be three different types of SMR drives: Device managed, Host aware and Host managed. It is my belief that only 'Device managed' drives are shipping which any file system can use, but the file system has no mechanisms to leverage or control the drives behavior hence they

Re: Zoned Commands ZBC/ZAC, Shingled SMR drives, ZFS

2015-03-24 Thread Shehbaz Jaffer
'host aware' or 'host managed' SMR drives open the real possibilities for use under ZFS and other file systems. Agreed. Probably RAID is not the way to go then. In host managed SMR drives one could use other form of resiliency (Erasure Codes) rather than RAID. We do not rebuild the whole disk

Re: Zoned Commands ZBC/ZAC, Shingled SMR drives, ZFS

2015-03-24 Thread Tom Evans
On Tue, Mar 24, 2015 at 12:47 PM, Shehbaz Jaffer shehbazjaffer...@gmail.com wrote: Hi, I was wondering what cost advantage do SMR drive provide as compared to normal CMR drive? 8TB SMR drive - $ 260 3TB CMR (Conventional Magnetic Recording drive) - $ 105 Purchase price is not irrelevant,

RE: Zoned Commands ZBC/ZAC, Shingled SMR drives, ZFS

2015-03-24 Thread Dale Kline
READ THE DOCUMENTATION THOROUGHLY on these SMR drives. There are serious WRITE restrictions on these drives because of the overlapping (shingled) tracks. I have read over several times and am still not sure of all of the caveats. As Tom states below, they are to be used mainly in WRITE

Re: Zoned Commands ZBC/ZAC, Shingled SMR drives, ZFS

2015-03-24 Thread Don Lewis
On 24 Mar, InterNetX - Juergen Gotteswinter wrote: The HGST He8 HDDs completed its rebuild in 19 hours and 46 minutes. The Seagate Archive HDDs completed their rebuild in 57 hours and 13 minutes this is ... a feature. right? Looks like the HGST He8 drives cost about $600 though ... The He10