Unsolved
This post is more than 5 years old
37 Posts
0
647
May 25th, 2010 13:00
System Limits for Linux
I would like to know if anyone knows the maximum number of LUNs that can be under control by Powerpath v.5.3.0 on Linux (SLES 9, SP3). I know there is a maximum of unique LUNs and a maximum number of paths (#LUNs * # of storage array ports) that are supported. Do you know what those limits are? The reason why I am asking is that the documentation shows different values in different places. One document states 128, whereas an other document shows how to increase it to 3000 without stating what the maximum value is. I also opened a SR with EMC and they said 128.
This is what I have so far:
System Limitations
Layer |
Limit |
Value |
Note |
Storage |
Max # of LUNs per FA |
65536 |
|
Max # of targets |
32 Clariion SP Ports 32 Symm FAs |
||
OS with Emulex |
# of HBAs |
16 |
Same vendor and PCI type |
Max # of LUNS seen by SLES 10 |
65536 (Emulex) 1024 (EMC) 8192 (EMC SP3 or higher) |
||
Highest Address |
16384 (EMC) |
||
Powerpath |
Max. # of LUNs per server |
128 |
Seems to work today with 146 Modify (max_fds parameter in the /etc/multipath.conf) |
Max # of Paths to a LUN |
32 |
||
Nollaig1
1 Rookie
•
137 Posts
0
August 3rd, 2010 00:00
Hello Uwe,
The Operating System usually dictates how many LUNs are supported. From the Connectivity guide, the theoretical maximuns are listed in table format on page 21. But these are theoretical Max limits, and the OS may in reality limit this further for example in the same guide it notes:
Red Hat currently supports a maximum of 1024 devices on any RHEL 4 system.
The EMC support limit is based on the Red Hat limitation and internal qualification.
The table of theoretical Max limits and the actual limits are listed in the "EMC Host Connectivity Guide for Linux" available for download on powerlink.
I hope this helps,
Regards,
Nollaig