LVM1 과 LVM2의 차이점(버젼별 SIZE LIMIT)

[이누기]

출처: http://www.redhat.com/magazine/009jul05/features/lvm2/#diffs

Differences between LVM1 and LVM2

The new release of LVM, LVM 2, is available only on Red Hat Enterprise Linux 4 and later kernels. It is upwardly compatible with LVM 1 and retains the same command line interface structure. However it uses a new, more scalable and resilient metadata structure that allows for transactional metadata updates (that allow quick recovery after server failures), very large numbers of devices, and clustering. For Enterprise Linux servers deployed in mission-critical environments that require high availability, LVM2 is the right choice for Linux volume management. Table 1. A comparison of LVM 1 and LVM 2 summarizes the differences between LVM1 and LVM2 in features, kernel support, and other areas.

Features	LVM1	LVM2
RHEL AS 2.1 support	No	No
RHEL 3 support	Yes	No
RHEL 4 support	No	Yes
Transactional metadata for fast recovery	No	Yes
Shared volume mounts with GFS	No	Yes
Cluster Suite failover supported	Yes	Yes
Striped volume expansion	No	Yes
Max number PVs, LVs	256 PVs, 256 LVs	2**32 PVs, 2**32 LVs
Max device size	2 Terabytes	8 Exabytes (64-bit CPUs)
Volume mirroring support	No	Yes, in Fall 2005

Table 1. A comparison of LVM 1 and LVM 2

Summary

The Linux Logical Volume Manager provides increased manageability, uptime, and performance for Red Hat Enterprise Linux servers. You can learn more about LVM by visiting to following websites

LVM1과 LVM2의 LV의 크기 제한은?

4.1.13. What is the maximum size of a single LV?

The answer to this question depends upon the CPU architecture of your computer and the kernel you are a running:

• For 2.4 based kernels, the maximum LV size is 2TB. For some older kernels, however, the limit was 1TB due to signedness problems in the block layer. Red Hat Enterprise Linux 3 Update 5 has fixes to allow the full 2TB LVs. Consult your distribution for more information in this regard.

• For 32-bit CPUs on 2.6 kernels, the maximum LV size is 16TB.

• For 64-bit CPUs on 2.6 kernels, the maximum LV size is 8EB. (Yes, that is a very large number.)

[이누기]

RHEL3에서 사용하는 LVM1에서는 LOGICAL VOLUME 의 사이즈가 2 Tera로 제한되는 한계가 있다.
# vgextend sniper /dev/hda7
vgextend -- INFO: maximum logical volume size is 2 Terabyte