[linux-lvm] Re: IBM to release LVM Technology to the Linux
Dale Kemp
dale at inet.net.nz
Mon Jun 26 23:18:16 UTC 2000
"Wilson, Eric" wrote:
> I have to agree with Dale on this. So far the Linux LVM implementation seems
> less than "Enterprise server mission critical." I don't mean to seem harsh or
> negative, but my person life mission is to replace NT with Linux in every
> instance possible. To widen the usage of Linux, Linux MUST be seen as reliable,
> mission critical, but also easy to get it that way and keep it that way. (for
> the point and click boys)
>
> I will openly admit to being in love with the AIX LVM. the reasons are really
> quite simple: A database server running several Terabytes of data can easily be
> massaged without fear of screwup or failure. The LINUX LVM must adhere to these
> same all or nothing, rock solid philosophies to crush Microsoft.
>
> I realize I'm preaching to the choir, but Dale's primary premise holds true: To
> get Linux and it's LVM out of the Uni. or LAB and into the Enterprise
> datacenter; it must be foolproof.
Hi Eric,
I think you mean "Ben" not "Dale" in the above reply? You could just as easily
apply your "Enterprise server mission critical" badge to the whole on Linux, but
the facts are Linux is moving into these areas even with the "Uni. or LAB"
development process. I agree with everything else you say, stability is one of the
main things that Linux has over NT. I've used NT for a short period of time and
it wasn't a pleasant experience, it crashed four times just trying to install it.
And
people treat this as a "enterprise level" system !?!
Looking at the Linux VFS (Virtual FileSystem) seems to show up some problems,
for example I was more than surprised to find a big union with all the inode types
from every kind of filesystem in Linux. And yet there is still a call to register a
filesystem
with VFS. VFS is certainly not abstract. Any good OO programmer would have never
done it this way. Maybe we need SGIs Irix/vfs system more than we
need their XVM. See the white paper at SGI - "Porting the SGI XFS
File System to Linux", for more on this.
Linux VFS should know nothing about other filesystems until its told about them,
for example when you insert a filesystem module into the kernel.
[ Sorry this is a bit off topic for this list, but I feel its still important
to the overall linux filesystem itself. ]
>From File: fs.h
struct inode {
struct list_head i_hash;
struct list_head i_list;
struct list_head i_dentry;
unsigned long i_ino;
unsigned int i_count;
kdev_t i_dev;
umode_t i_mode;
nlink_t i_nlink;
uid_t i_uid;
gid_t i_gid;
kdev_t i_rdev;
loff_t i_size;
time_t i_atime;
time_t i_mtime;
time_t i_ctime;
unsigned long i_blksize;
unsigned long i_blocks;
unsigned long i_version;
struct semaphore i_sem;
struct semaphore i_zombie;
struct inode_operations *i_op;
struct file_operations *i_fop; /* former ->i_op->default_file_ops */
struct super_block *i_sb;
wait_queue_head_t i_wait;
struct file_lock *i_flock;
struct address_space *i_mapping;
struct address_space i_data;
struct address_space i_data;
struct dquot *i_dquot[MAXQUOTAS];
struct pipe_inode_info *i_pipe;
struct block_device *i_bdev;
unsigned long i_state;
unsigned int i_flags;
unsigned char i_sock;
atomic_t i_writecount;
unsigned int i_attr_flags;
__u32 i_generation;
union {
struct minix_inode_info minix_i;
struct ext2_inode_info ext2_i;
struct hpfs_inode_info hpfs_i;
struct ntfs_inode_info ntfs_i;
struct msdos_inode_info msdos_i;
struct umsdos_inode_info umsdos_i;
struct iso_inode_info isofs_i;
struct nfs_inode_info nfs_i;
struct sysv_inode_info sysv_i;
struct affs_inode_info affs_i;
struct ufs_inode_info ufs_i;
struct efs_inode_info efs_i;
struct romfs_inode_info romfs_i;
struct coda_inode_info coda_i;
struct smb_inode_info smbfs_i;
struct hfs_inode_info hfs_i;
struct adfs_inode_info adfs_i;
struct qnx4_inode_info qnx4_i;
struct bfs_inode_info bfs_i;
struct udf_inode_info udf_i;
struct ncp_inode_info ncpfs_i;
struct ncp_inode_info ncpfs_i;
struct proc_inode_info proc_i;
struct socket socket_i;
struct usbdev_inode_info usbdev_i;
void *generic_ip;
} u;
};
-- Dale.
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