You can go into the CLI and run the command to ensure that the cache is enabled. What I would recommend to do first is try syncing the clocks in the GUI. Then after that if you look at pages 189-192 it lists a number of commands. The main ones you would want to do is the:
In other words you get multiple Cache not enabled errors in the log? They never stop? In my experience you never get anything stating it is back on, it just stops generating the message and expected performance comes back.
Lots of things can cause the cache to be what is supposed to be temporarily diabled on the MD iSCSI sans.
The best way to verify that the cache is enabled would be to pull a support bundle and look in the storage array profile. If you search for "write cache" it should take you to the section about the cache and show if it is enabled or disabled. Hope this helps.
It can be disabled by a Battery Learn Cycle and they will not report that it is off in storage profile. Controller ownership conflicts between associated disk copy pairs / snapshots can disable it too without reporting it in storage profile.
Maybe it's better in the new MD's, my experience is mainly with MD3000i's and MD3220i's.
The no more errors is the key.... Don't panic if it's being a little slow and you see the messages again. A battery learn cycle will shut it off temporarily. You cna schedule those sort of, to make them happen during any regular low demand period except they can take a long time. (too long)
DELL-Kenny K
685 Posts
1
January 20th, 2012 12:00
You can go into the CLI and run the command to ensure that the cache is enabled. What I would recommend to do first is try syncing the clocks in the GUI. Then after that if you look at pages 189-192 it lists a number of commands. The main ones you would want to do is the:
mirrorCacheEnabled=TRUE
writeCacheEnabled=TRUE
Here is the link in case you have any questions.
support.dell.com/.../CLIMR.pdf
Let us know how it goes.
JOHNADCO
2 Intern
•
847 Posts
0
January 20th, 2012 11:00
In other words you get multiple Cache not enabled errors in the log? They never stop? In my experience you never get anything stating it is back on, it just stops generating the message and expected performance comes back.
Lots of things can cause the cache to be what is supposed to be temporarily diabled on the MD iSCSI sans.
spgsit
2 Intern
•
185 Posts
0
January 20th, 2012 12:00
Thanks for the pointers, really!, will report as soon as had the chance to do it over the weekend
Seb
spgsit
2 Intern
•
185 Posts
0
January 20th, 2012 13:00
smcli has really confusing syntax (the set command must be executed from script)
But I set them as advised, log shows nothing different, that is normal?
Seb
DELL-Kenny K
685 Posts
0
January 20th, 2012 13:00
The best way to verify that the cache is enabled would be to pull a support bundle and look in the storage array profile. If you search for "write cache" it should take you to the section about the cache and show if it is enabled or disabled. Hope this helps.
JOHNADCO
2 Intern
•
847 Posts
0
January 20th, 2012 14:00
It can be disabled by a Battery Learn Cycle and they will not report that it is off in storage profile. Controller ownership conflicts between associated disk copy pairs / snapshots can disable it too without reporting it in storage profile.
Maybe it's better in the new MD's, my experience is mainly with MD3000i's and MD3220i's.
spgsit
2 Intern
•
185 Posts
0
January 21st, 2012 07:00
Thanks guys, it shows for every VD Write cache: Enabled
which I hope is the correct state (and no more errors in log)
Seb
JOHNADCO
2 Intern
•
847 Posts
0
January 23rd, 2012 07:00
The no more errors is the key.... Don't panic if it's being a little slow and you see the messages again. A battery learn cycle will shut it off temporarily. You cna schedule those sort of, to make them happen during any regular low demand period except they can take a long time. (too long)