All,<br>I recently raised a question about unbalanced OSTs and received the right answer - increase the size of the OSTs. So I set forth to do this on<br>our DDN controllers and rather than having 32 1TB LUNs i decided to go with 4 8TB LUNs instead. In doing this I learned our LUNs were created <br>
with the default 512 size and from reading the manual it appears it would improve performance for our work to go with 4096. Since most jobs run <br>on lustre would be creating larger files (sequential) we're not concerned about losing space from smaller files taking up a 4k block. Is there any other concern I should have <br>
with going with the larger block size?<br><br>Second question for the DDN expert- We have 4 OSS's connected to DUAL DDN 9550 controllers via fiber. With the older configuration we had<br>one 1TB LUN using one Tier so the lun output looked something like this:<br>
<br> Logical Unit Status <br><br> Capacity Block<br> LUN Label Owner Status (Mbytes) Size Tiers Tier list<br>-------------------------------------------------------------------------------<br>
0 lun 0 1 Ready 1120098 512 1 1 <br> 1 lun 1 1 Ready 1120098 512 1 2 <br> 2 lun 2 1 Ready 1120098 512 1 3 <br> 3 lun 3 1 Ready 1120098 512 1 4 <br>
4 lun 4 1 Ready 1120098 512 1 5 <br> 5 lun 5 1 Ready 1120098 512 1 6 <br> 6 lun 6 1 Ready 1120098 512 1 7 <br> 7 lun 7 1 Ready 1120098 512 1 8 <br>
8 lun 8 2 Ready 1120098 512 1 9 <br> 9 lun 9 2 Ready 1120098 512 1 10 <br><br><br>After making the change to only 4 LUNs two of my OSS's don't see any SCSI devices when i run fdisk. By deleting and recreating the luns did I somehow cause <br>
a zoning issue? Thanks in advance.<br><br>Syed<br>