As we know, in ZFS, it is recommended to keep the disk usage below 80% to ensure the performance.
However, the following is my scenario:
I have a ZFS storage, which share by multiple servers, and overall Usage is lower than 80%.
Server A has multiple Lun (spool) from this storage, For example:
Currently, LUNPOOL/B of server A is more than 80%, it reach 88%.
Since the overall storage there still lower than 80 %, will the performance for this LUNPOOL/B be affected?
What we recommend is that overall pool capacity should remain below 80% for best performance.
Actually for all Solaris 11 releases and starting at the Solaris 10 1/13 release, pool capacity can reach 90% before
performance is impacted.
I'm not quiet sure I'm following this configuration so please it to me:
1. Server A runs Solaris 10 and has a LUNPOOL exported from a ZFSSA?
2. LUNPOOL/A, B, C, are all file systems? If so, do they quotas set? Otherwise, all file systems consume all pool space so I don't see how LUNPOOL/B of server A could reach 88% unless it has a quota.
3. I wonder if A, B, and C are not file systems but volumes?
Consider that the 80 or 90% is a pool capacity recommendation, not an individual storage recommendation, but maybe I misunderstand.
In the zfs storage:
LUNPOOL present it to server A
SERVERB present it to server B
Usage on this zfs storage is 72.3% of 15T
root@ServerA # zpool list
NAME SIZE ALLOC FREE CAP HEALTH ALTROOT
A 99.5G 26.3G 73.2G 26% ONLINE -
B 992G 59.9G 932G 6% ONLINE -
C 1.94T 1.75T 191G 90% ONLINE -
D 199G 4.29G 195G 2% ONLINE -
rpool 278G 80.7G 197G 29% ONLINE -
as you can see the zpool "C" in the zpool list output reported by Solaris 10 has reach 90%
So do you think it has a performance issues?
Thanks for the zpool status output, which cleared up all my questions.
I see that pool C is at 90% and you are asking about performance. I think you are going to have to tell us if the performance has suffered since reaching 90%.
Our current guideline for Solaris 10 1/13 releases, is keeping pool capacity at 90%. If the workload is mostly static, read-only, then you can increase this pool capacity limit to 95%. Whether a pool has a performance issue at 90% is also related to the workload.If you don't have a pool performance problem at 90% because the pool performs well or as expected, then you're fine for now. If the pool performance is sluggish as it reached 90%, then see if you can archive some data to reduce space below 90%. If the pool performance recovers, then you know that this particular pool's workload performs best below 90%.