3PAR 8440 NL 6TB Raid 6 disk speed. Seems low to me.

[Mcicool]

Good time of day! I write here cz i have doubts related to my NL array (Raid6 of 8x6TB NL Drives) speed.

Here is CrystalDiskmark output (tested on esxi 7 windows VM). Write speed seems pretty low to me.

[Read]
SEQ 1MiB (Q= 8, T= 1): 810.058 MB/s [ 772.5 IOPS] < 10319.66 us>
SEQ 1MiB (Q= 1, T= 1): 603.622 MB/s [ 575.7 IOPS] < 1736.06 us>
RND 4KiB (Q= 32, T=16): 160.784 MB/s [ 39253.9 IOPS] < 12907.96 us>
RND 4KiB (Q= 1, T= 1): 14.226 MB/s [ 3473.1 IOPS] < 287.44 us>

[Write]
SEQ 1MiB (Q= 8, T= 1): 203.618 MB/s [ 194.2 IOPS] < 40792.80 us>
SEQ 1MiB (Q= 1, T= 1): 155.404 MB/s [ 148.2 IOPS] < 6727.50 us>
RND 4KiB (Q= 32, T=16): 6.111 MB/s [ 1491.9 IOPS] <326062.70 us>
RND 4KiB (Q= 1, T= 1): 3.595 MB/s [ 877.7 IOPS] < 1138.59 us>

Also would be nice to know if SSD (Raid6 of 8x 1.92Tb) output is relevant:

[Read]
SEQ 1MiB (Q= 8, T= 1): 824.539 MB/s [ 786.3 IOPS] < 10157.54 us>
SEQ 1MiB (Q= 1, T= 1): 604.030 MB/s [ 576.0 IOPS] < 1735.07 us>
RND 4KiB (Q= 32, T=16): 408.611 MB/s [ 99758.5 IOPS] < 4486.84 us>
RND 4KiB (Q= 1, T= 1): 34.788 MB/s [ 8493.2 IOPS] < 117.34 us>

[Write]
SEQ 1MiB (Q= 8, T= 1): 821.864 MB/s [ 783.8 IOPS] < 10172.68 us>
SEQ 1MiB (Q= 1, T= 1): 440.649 MB/s [ 420.2 IOPS] < 2375.87 us>
RND 4KiB (Q= 32, T=16): 334.186 MB/s [ 81588.4 IOPS] < 6257.91 us>
RND 4KiB (Q= 1, T= 1): 20.330 MB/s [ 4963.4 IOPS] < 200.97 us>

[sbhat09]

Hello @Mcicool,

This is the expected difference between NL and SSD. Especially write speed will be very low in NL disks compared to SSD.

You can find more insights about this in this document - https://www.seagate.com/files/www-content/solutions/mach-2-multi-actuator-hard-drive/files/tp714-dot-2-2006us-mach-2-technology-paper.pdf

Regards,
Srinivas Bhat

If you feel this was helpful please click the KUDOS! thumb below!

[Mcicool]

I understand that there is a difference... But i think its too low and i believe that there should be a way to boost it a bit. Lets say on my DL380 Raid6 of SAS disks is twice faster. Maybe some 3PAR tuning... or something

200 mb/s linear write speed is a speed of consumer HDD. Maybe cache issue?

[sbhat09]

Hello @Mcicool,

Is that a newly installed or newly capacity upgraded 3PAR? Are there any region movement tasks running (Like tunesys, compacting, AO region movement)? You can check that with the command 'showtask -active'. If there are no such tasks active, run the check once more. Repeat the check on the weekend or Monday again.

Regards,

Srinivas Bhat

[Mcicool]

Says "no tasks" active. Its freshly installed 3PAR.