Attachment uploads are currently disabled. This is a temporary situation and will resume as normal in the coming days.
Solved!
Go to SolutionS
Symmetrix_
1 Rookie
•
73 Posts
1
4314
June 14th, 2013 10:00
VMAX write cach limit
Is there is a limit of the write cache on the VMAXs ? if a VMAX is scalable up to 1TB usable cache size , then what is the limit for write cache ?
Using the output from the symcfg list -v command as Quincy indicated you will see something like this:
symcfg –sid XXX list -v
Cache Size (Mirrored) : 172032 (MB)
# of Available Cache Slots : 2478112
Max # of System Write Pending Slots : 1490739
Max # of DA Write Pending Slots : 745369
Max # of Device Write Pending Slots : 74536
Replication Cache Usage (Percent) : 1
I take the numbers above and translate everything to GB
So the total Mirrored Cache on the array:
172032 / 1024 = 168GBThe total Usable Cache would be:
2478112 * 64 / 1024 / 1024 = 151.3GBThe total system Write Cache would be:
1490739 * 64 / 1024 / 1024 = 90.9GBAnd the maximum usable Volume Write Cache would be:
74536 * 64 / 1024 / 1024 = 4.5GBYou can see from the numbers above that the Replication_Policy is set on this array so the write cache is 60% of the usable cache.
Quincy561
1281 Posts
1125
0
Posted June 14th, 2013 10:00
The writable cache is usually set to 80% or 75% of usable cache.
You can find the amount you have with the symcfg list -v command