Thanks.
I already can see this on one of the more used ones:
cp_from_timer = 288539 cp_from_snapshot = 210065 cp_from_low_water = 0 cp_from_high_water = 2 cp_from_log_full = 138834 cp_from_timer_nvlog = 10 cp_from_cp = 6006
Can someone from NetApp answer on if it would be useful to have an upgrade for such machine ?
Eyal.
Bruce Sterling Woodcock wrote:
----- Original Message ----- From: Eyal Traitel eyal.traitel@motorola.com To: Karl Swartz kls@netapp.com Cc: Jay Orr orrjl@stl.nexen.com; lrazo@netapp.com; toasters@mathworks.com Sent: Saturday, February 19, 2000 2:28 AM Subject: Re: NVRAM memory
Karl,
I'm not Karl, but I'm awake, so... :)
Why haven't you given the option to upgrade to bigger then 32MB NVRAMs ? It seems as a logical upgrade path for heavy write-based installations.
This I don't know, other than the fact that you have the battery power to support it and the loading requirements for a PCI slot and so on.
I would also be inclined to believe that heavy write-based installations that would benefit from MORE than 32MB are fairly rare. Few filers are sitting there getting 16MB of writes every second. .
How can I check what's the utilization of the NVRAM (if my triggers are more "full NVRAM" or "10sec.") ?
Run systat 1 on the console and watch the disk writes. Whenever the NVRAM gets flushed, the value on disk writes will got from 0 to whatever. If you only see a couple of lines every 10 seconds, then your NVRAM isn't getting half-full usually; if it is writing more than ever 5 seconds, you're pretty write-intensive. If it's almost constant, you'd benefit from more NVRAM.
Of course, this is just one-time look. You'd want to monitor your filer at multiple times during heavy load problems. If you want some more general statistics of your filer's NVRAM load over time, you can go into rc_toggle_basic mode and type wafl_susp -w. In the output you'll see values for cp_from_timer (how many times NVRAM was flushed to disk at the 10 second mark), cp_from_log_full (how many times it was flushed because the NVRAM filled up), and the all-important cp_from_cp (how many times NVRAM filled up, it tried to flush to disk, and another flush was already in progress and had not yet completed). Fush == cp == consistency point.
However, don't ask me to interpret all the stuff in wafl_susp -w and don't blame me if you type to wrong thing in rc_toggle_basic mode and accidentally wipe out your filesystem. Don't fool around in this mode; it can render your filer inoperable. Get in, type wafl_susp -w, and get out (type rc_toggle_basic again).
Bruce