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storage:svc_bestpractice [2022/08/09 01:15] manu [Linux optimization] |
storage:svc_bestpractice [2025/03/04 19:05] (current) manu [Linux optimization] |
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===== SVC Best practice with IBM storage ===== | ===== SVC Best practice with IBM storage ===== | ||
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+ | ===== SVC Enhanced Stretch Cluster ====== | ||
+ | |||
+ | For stretched systems that use the enhanced configuration functions, **storage systems that are configured to one of the main sites (1 or 2) need be zoned only to be visible by the nodes in that site**. Storage systems in site 3 or storage systems that have no site that is defined must be zoned to all nodes. | ||
+ | |||
+ | Note: ISLs must not be shared between private and public virtual fabrics. | ||
+ | |||
+ | Configure Enhanced Stretch Cluster | ||
+ | |||
+ | https://www.ibm.com/docs/en/spectrumvirtualsoftw/8.2.x?topic=details-configuring-enhanced-stretched-system | ||
+ | |||
+ | ===== Speed for mirroring ===== | ||
For information, for volume mirroring, the max speed is sync rate 100% corresponding to 64MB/s | For information, for volume mirroring, the max speed is sync rate 100% corresponding to 64MB/s | ||
+ | |||
+ | ==== SAN switches ==== | ||
+ | |||
+ | **buffer credit on SAN switches** | ||
+ | 40 for 16Gb or 32Gb | ||
+ | |||
+ | |||
+ | **workload segregation** | ||
+ | on storage dedicated ports for high speed traffic ex: 32Gb | ||
+ | and other ports for lower speed 8Gb / 16Gb using zoning | ||
+ | |||
==== FCM optimization ==== | ==== FCM optimization ==== | ||
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When using **compression on storage**, reduce block size on host to a value lower than **64k** | When using **compression on storage**, reduce block size on host to a value lower than **64k** | ||
+ | |||
+ | FIXME v8.4 and higher: Where possible limit the maximum transfer size sent to the IBM FlashSystem to | ||
+ | no more than **256 KiB**. This limitation is general best practice and not specific to only | ||
**Details**\\ | **Details**\\ | ||
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==== Linux optimization ==== | ==== Linux optimization ==== | ||
+ | |||
+ | FIXME v8.4 and higher: Where possible limit the maximum transfer size sent to the IBM FlashSystem to | ||
+ | no more than **256 KiB**. This limitation is general best practice and not specific to only | ||
Using compression on SVC volumes, the best is to set IO size to 64k | Using compression on SVC volumes, the best is to set IO size to 64k | ||
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</cli> | </cli> | ||
+ | Use the command : **udevadm info -a** | ||
===== Perf issue on SAN / Storage ===== | ===== Perf issue on SAN / Storage ===== | ||
[[storage:brocade_pb#buffer_credit_problem|Brocade buffer credit]] | [[storage:brocade_pb#buffer_credit_problem|Brocade buffer credit]] | ||
+ | ===== CPU usage with DR pool ===== | ||
+ | |||
+ | When you use DR pool volume deletion will use high CPU (lower than 20% in current usage) you can easily reach 60% of CPU during deletion process. | ||
+ | |||
+ | To check deletion, there is only one way, but no progress status ! | ||
+ | <cli prompt='>'> | ||
+ | IBM_FlashSystem:V5100-02:superuser>lsvdiskcopy | grep del | ||
+ | 125 l0000-DB01 0 deleting yes no 0 Pool0 200.00GB striped no on balanced yes 0 Pool0 no yes | ||
+ | 148 l0000-tap04 0 deleting yes no 0 Pool0 200.00GB striped no on balanced yes 0 Pool0 no yes | ||
+ | 149 l0000-tap03 0 deleting yes no 0 Pool0 200.00GB striped no on balanced yes 0 Pool0 no yes | ||
+ | 150 l0000-tap01 0 deleting yes no 0 Pool0 200.00GB striped no on balanced yes 0 Pool0 no yes | ||
+ | 151 l0000-tap02 0 deleting yes no 0 Pool0 200.00GB striped no on balanced yes 0 Pool0 no yes | ||
+ | </cli> | ||
+ | |||
+ | Usually if the CPU is not above 90% it is not considered as high and it is not affecting the performance. |