RAID 1+0 & disk arrangement

[TanelKokk]

I have DL385 + SA 6404 + 6xSCSI disk.

I want to make RAID 1+0 volume. This means 3xRAID1 are striped together. My question is, how SA6404 arranges those mirrors? Does it matter, which scsi disks are attached to which scsi port/channel (6404 has 2 internal scsi port)?

Tanel

[TanelKokk]

IMHO one part of mirror should attached to scsi port 1 and the other part should attached to scsi port 2.

[Oleg Koroz]

You should not have any problem to create such configuration, however if you take a
look ... with SCSI backplane you can make 2 and 4 HDD per Port 1 and 2 or all 6 HDD used with one channel, otherwise with duplex you have to borrow 1 HDD from left side and add to right side trough configuration, and I/O for this guy have to go trough channel 1. That might get complicated within 6400 I/O if write load increase, unless you use at least 256MB BBWC.

[TanelKokk]

So what is the most efficient configuration for RAID1+0 volume over 6 SCSI disk:

array A
physicaldrive 1:0 (port 1:id 0 , Parallel SCSI, 146.8 GB, OK)
physicaldrive 1:1 (port 1:id 1 , Parallel SCSI, 146.8 GB, OK)
physicaldrive 2:2 (port 2:id 2 , Parallel SCSI, 146.8 GB, OK)
physicaldrive 2:3 (port 2:id 3 , Parallel SCSI, 146.8 GB, OK)
physicaldrive 2:4 (port 2:id 4 , Parallel SCSI, 146.8 GB, OK)
physicaldrive 2:5 (port 2:id 5 , Parallel SCSI, 146.8 GB, OK)

or:

array A
physicaldrive 1:0 (port 1:id 0 , Parallel SCSI, 146.8 GB, OK)
physicaldrive 1:1 (port 1:id 1 , Parallel SCSI, 146.8 GB, OK)
physicaldrive 1:2 (port 1:id 2 , Parallel SCSI, 146.8 GB, OK)
physicaldrive 1:3 (port 1:id 3 , Parallel SCSI, 146.8 GB, OK)
physicaldrive 1:4 (port 1:id 4 , Parallel SCSI, 146.8 GB, OK)
physicaldrive 1:5 (port 1:id 5 , Parallel SCSI, 146.8 GB, OK)

or something else?

Tanel

[Oleg Koroz]

I would take plan B
if you have enough time to play with it try both ...