IMHO the problem is placement within regions based on application activity.
The basic concept you want to follow: if the access is sequential in application terms the best I/O performance is achieved when the physical I/O access is sequential.
When application I/O is random there are many different things to consider - one of them being - is the I/O still physical, or is it VMM cached, or application cached.
In short, with modern systems (assuming more than one or two disks, i.e., separate volume groups for each application's data) there is no one best place.
Assuming some physical relationship the only advice that remains is that AIX LVM mirrored logical volumes with lots of write activity may benefit from being placed on the outer edge because the VGSA - Volume Group Status Area - is on the outer edge and gets updated anytime a mirrored LP is modified.
command you should look at: lslv - options: none, and with -l
lspv -p
This looks "bad" or less than ideal - 0% and in two regions - however, in physical terms it is a sequential as it gets. A simple command will improve the 0% to >50% (see below).
Here, I can see the logical volume is organized sequentially - starting in the center region, and proceeding into the "inner middle" region as one long sequence.
Now to get better stats I can do the following:
(change the preferred region to center from middle)
I was in smit, checking on disc space, etc. and it appears that one of our physical volumes that is part of a large volume group, has no free physical partitions. The server is running AIX 5.1. What would be the advisable step to take in this instance? (9 Replies)
Hello,
I have logical volume group of 50GB, in which I have 2 logical volumes, LogVol01 and LogVol02, both are of 10GB.
If I extend LogVol01 further by 10GB, then it keeps the extended copy after logical volume 2. I want to know where it keeps this information
Regards
Himanshu (3 Replies)
Does anyone have any simple methods for moving a current logical volume from one volume group to another? I do not wish to move the data from one physical volume to another. Basically, I want to "relink" the logical volume to exist in a different volume group. Any ideas? (2 Replies)
Hi!
Can anyone help me on how I can do a basic check on the Unix filesystems / physical volumes and logical volumes?
What items should I check, like where do I look at in smit? Or are there commands that I should execute?
I need to do this as I was informed by IBM that there seems to be... (1 Reply)
Hi,
Someone please help me with how i can unmount and remove all the files systems from a cluster. This is being shared by two servers that are active_standby. (3 Replies)
Hello,
I am a french computer technician, and i speak English just a little.
On Aix 5.3, I encounter a name conflict logical volume on two volume group.
The first volume lvnode01 is OK in rootvg and mounted. It is also consistent in the ODM
root # lsvg -l rootvg |grep lvnode01 ... (10 Replies)
Hi,
I am new to unix. I am working on Red Hat Linux and side by side on AIX also. After reading the concepts of Storage, I am now really confused regarding the terminologies
1)Physical Volume
2)Volume Group
3)Logical Volume
4)Physical Partition
Please help me to understand these concepts. (6 Replies)
hi,
I want to create a volume group of 200 GB and then create different file systems on that.
please help me out. Its becomes confusing when the PP calculating PP.
I don't understand this concept. (2 Replies)
When installing Linux, I choose some default setting to use all the disk space.
My server has a single internal 250Gb SCSI disk. By default the install appears to have created 3 logical volumes
lv_root, lv_home and lv_swap.
fdisk -l shows the following
lab3.nms:/dev>fdisk -l
Disk... (2 Replies)
Hello Guys,
I want to create a file system dedicated for an application installation. But there is no space in volume group to create a new logical volume. There is enough space in other logical volume which is being mounted on /var.
I know we can use that logical volume and create a virtual... (2 Replies)