I am planning to have a raid 5 array (software based) with LVM riding atop.
I have a few questions regarding the setup.
1- From Suse 10.0 Reference Manual: The physical extent size defines the size of a physical block in the volume group. All the disk space in a volume group is handled in chunks of this size. This value is normally set to 4 MB and allows for a maximum size of 256 GB for physical and logical volumes. The physical extent size should only be increased, for example, to 8, 16, or 32 MB, if you need logical volumes larger than 256 GB.
Is this a linear function, meaning??
PE Max Size
2- Raid setup: In the following config extract, do the hard drives have to be formatted first, or could I do like in extract 2:
I assume extract 1 has the drives partitionned with type fd ( raid autodetect)...which one is the right one!!!
raiddev /dev/md0 raid-level 5 nr-raid-disks 6 nr-spare-disks 0 persistent-superblock 1 parity-algorithm left-symmetric chunk-size 32 device /dev/sdb1 raid-disk 0 device /dev/sdc1 raid-disk 1 device /dev/sdd1 raid-disk 2 device /dev/sde1 raid-disk 3 device /dev/sdf1 raid-disk 4 device /dev/sdg1 raid-disk 5Extract 2: (using raw disk)
raiddev /dev/md0 raid-level 5 nr-raid-disks 6 nr-spare-disks 0 persistent-superblock 1 parity-algorithm left-symmetric chunk-size 32 device /dev/sdb raid-disk 0 device /dev/sdc raid-disk 1 device /dev/sdd raid-disk 2 device /dev/sde raid-disk 3 device /dev/sdf raid-disk 4 device /dev/sdg raid-disk 5 Then mkraid /dev/md0 3- Once the raid is setup, pvcreate /dev/md0 vgcreate -s16 data /dev/md0 lvcreate ( a bunch of lv's are created here) I plan to partition the lv's with reiserfs Some lv's will have lots of small files, where another will have tons of 700MB files.... does the PE size affect this ? If you have any suggestion to make this setup optimal, it would be greatly appreciated. The HD's will be SATA and PATA ( mixed, but on different busses) Thanks to everyone who will help. Patrick Picard Picard Consulting