HI,
Do it's possible to make Unlimited Shared Value for each VM?
I want to achieve in this way fast access to disks write/read
at this moment I have Shared Value set to 4000 and IOPs limit to Unlimited. Cannot set more that 4000 Shared Value (error popup from Client View say it must be between 200 a 4000.
Simple test write on Linux VM:
dd if=/dev/zero of=/mnt/trash/test-file bs=999k count=10k; rm /mnt/trash/test-file
10240+0 readed records
10240+0 writed records
10475274240 bytes (10 GB, 9,8 GiB) copied, 794,036 s, 13,2 MB/s
In that same machine with that same configuration (hw and soft) but without virtualize - system copied 1:1
dd if=/dev/zero of=/mnt/trash/test-file bs=999k count=10k; rm /mnt/trash/test-file
10240+0 readed records10240+0 writed records
10475274240 bytes (10 GB, 9,8 GiB) copied, 22,18s, 472 MB/s
It's a HUGE difference - how to change it?
I find the problem..
it turned out to be a hardware controller and Cache Ratio setting. In my case it was HP P410 Hw Controller
/opt/smartstorageadmin/ssacli/bin/ssacli ctrl all show config detail | head -40
Cache Board Present: True
Cache Status: OK
Cache Status Details: A cache error was detected. Run a diagnostic report for more information.
Cache Ratio: 100% Read / 0% Write
Drive Write Cache: Disabled
to fix it, the Cache Ratio must be forced by 50/50
/opt/smartstorageadmin/ssacli/bin/ssacli ctrl slot=2 modify cr=50/50 forced
and then suddenly the error disappears, and we can change it to the optimal setting for us.. for example 25 % Read / 75% Write
/opt/smartstorageadmin/ssacli/bin/ssacli ctrl slot=2 modify cr=25/75
/opt/smartstorageadmin/ssacli/bin/ssacli ctrl all show config detail | head -40
Smart Array P410 in Slot 2
Bus Interface: PCI
Slot: 2
[....]
Cache Board Present: True
Cache Status: OK
Cache Ratio: 25% Read / 75% Write
Drive Write Cache: Enabled
Total Cache Size: 256 MB
Total Cache Memory Available: 144 MB
dd if=/dev/zero of=/mnt/trash/test-file bs=999k count=10k; rm /mnt/trash/test-file
10240+0 readed records
10240+0 writed records
10475274240 bytes (10 GB, 9,8 GiB) copied, 27,8135 s, 377 MB/s
I find the problem..
it turned out to be a hardware controller and Cache Ratio setting. In my case it was HP P410 Hw Controller
/opt/smartstorageadmin/ssacli/bin/ssacli ctrl all show config detail | head -40
Cache Board Present: True
Cache Status: OK
Cache Status Details: A cache error was detected. Run a diagnostic report for more information.
Cache Ratio: 100% Read / 0% Write
Drive Write Cache: Disabled
to fix it, the Cache Ratio must be forced by 50/50
/opt/smartstorageadmin/ssacli/bin/ssacli ctrl slot=2 modify cr=50/50 forced
and then suddenly the error disappears, and we can change it to the optimal setting for us.. for example 25 % Read / 75% Write
/opt/smartstorageadmin/ssacli/bin/ssacli ctrl slot=2 modify cr=25/75
/opt/smartstorageadmin/ssacli/bin/ssacli ctrl all show config detail | head -40
Smart Array P410 in Slot 2
Bus Interface: PCI
Slot: 2
[....]
Cache Board Present: True
Cache Status: OK
Cache Ratio: 25% Read / 75% Write
Drive Write Cache: Enabled
Total Cache Size: 256 MB
Total Cache Memory Available: 144 MB
dd if=/dev/zero of=/mnt/trash/test-file bs=999k count=10k; rm /mnt/trash/test-file
10240+0 readed records
10240+0 writed records
10475274240 bytes (10 GB, 9,8 GiB) copied, 27,8135 s, 377 MB/s