On Tue, Feb 20, 2001 at 08:16:55AM -0800, White, Lance wrote:
No, it uses FW Ultra SCSI-3 disks, not FC. Yes, NDMP backup is supported. Limitations? Well, as it's positioned to be the NEW entry level Netapp (at 3300 NFS ops/sec, it actually about 30% faster than the old low end F720, and about 30% less expensive), it IS limited to 648GB MAX storage (6 internal plus 12 external in 18GB & 36GB flavors), as opposed to the F720's limit of ~500GB. Still doin' hot swap, RAID4, snapshots, OnTap, WAFL, everything that's cool about a Filer and more! :-D
The box sounds cool. It's about time a box of this price point was available again :)
I have a (long-time) gripe in the way it's advertised. It's a gripe I have with every vendor. I wish NetApp would advertise the *usable* diskspace of the machine (as seen by a client OS or df, for example), not the raw diskspace calculated by taking the disk vendor size and multiplying by the number of disks.
I know this makes the boxes appear more expensive per usable megabyte, but it's being more honest to the client, and once you explain to the client to take into account all the overheads, and how to do the same math on competing options (e.g, h/w raid + vxfs on Solaris, EMC, etc), then you (NetApp) appear to be delivering accurate technical information.
For example, there's no WAY an F720 has 500 GB of usable space. Out of the box, with default snap reserve, it barely has 300 GB, where GB == 2^30, which is what client based tools (such as df and the `Properties' box in Windows) use, not 10^9, which is what (overzealous) disk vendors use.
The usuable capacity of an F720 is trivial to calculate: 14 x 36 GB disks, utilised as: 1 hot spare, 1 parity, 12 data disks
Each data disk has 24840 MB usable, calculated as: 34500 megabytes (rightsized by OnTAP) - 10% wafl overhead (is this 8% in OnTAP 6.x?) - 20% snap reserve (default; but often reduced to 10%) = 24840 megabytes
So, 12 x 24840 = 298080 MB = ~ 291 GB
Tweaking the numbers to 8% wafl overhead (from OnTAP 6) and 10% snap reserve gives an F720 approximately 334 GB of space (from 500 GB `raw').
Based on the info Lance White gives above, an F85 with 36 GB drives, consisting of 15 data disks, 1 hot spare, 2 parity, 8% wafl overhead, 10% snap reserve would have a usuable capacity at the client of: 15 x (34500 - 8% - 10%) = 15 x 28556 = 428490 MB = 418 GB
418 GB is a bit less than the ``648 GB MAX storage'' that Lance quotes above.
In general, take away approximately one third of the raw capacity that NetApp quote and that will give you an guestimate on the usuable capacity that will suit most client's needs.
Luke.
PS: I'm sure some people have seen or heard this rant before :)
Disclaimer: I like NetApp. I worked at NetApp for a while as an SE. I just believe in being honest to the technical people you're selling to, especially those who have to justify to their management why the (not cheap) 500 GB box they bought ran out of space at 300 GB.
-- Luke Mewburn lukem@wasabisystems.com http://www.wasabisystems.com Luke Mewburn lukem@netbsd.org http://www.netbsd.org Wasabi Systems - providing NetBSD sales, support and services.