Dell PowerStore 1200T EMC PowerStore Host Configuration Guide - Page 69

Creating a File System, Mounting iSCSI File Systems

Get Dell PowerStore 1200T PDF manuals and user guides View all Dell PowerStore 1200T manuals
Add to My Manuals
Save this manual to your list of manuals

Page 69 highlights

in memeory only, until you decide to write them. After that, of course, the previous content won't be recoverable. Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite) Command (m for help): p Disk /dev/mapper/3514f0c5b12a00004: 1649.3 GB, 1649267441664 bytes 255 heads, 63 sectors/track, 200512 cylinders, total 3221225472 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 16384 bytes / 65536 bytes Disk identifier: 0x12d4e90c Device Boot Start End Blocks Id System In this mode, rather than using "cylinders" for creating partitions, the fdisk command uses sectors, which are a direct mapping to the LBA space of the cluster. Thus, to verify that the partition is aligned, simply verify that the starting sector number is a multiple of 16 (16 sectors, at 512 bytes each, is 8 KB). The fdisk command defaults to a starting sector for the first partition of 2048, which is divisible by 16, and thus is correctly assigned. Creating a File System When creating a file system with PowerStore cluster storage, use its default block size, and disable UNMAP during creation. It is recommended to create the file system using its default block size (using a non-default block size may lead to unexpected behavior). See your operating system and file system documentation. NOTE: Creating a file system with UNMAP enabled on a host connected to PowerStore may result in an increased amount of write I/Os to the storage subsystem. It is highly recommended to disable UNMAP during file system creation. To disable UNMAP during file system creation: ● When creating a file system using the mke2fs command - Use the "-E nodiscard" parameter. ● When creating a file system using the mkfs.xfs command - Use the "-K" parameter. For a more efficient data utilization and better performance, use Ext4 file system with PowerStore cluster storage instead of Ext3. For details about converting to Ext4 file system (from either Ext3 or Ext2), See Upgrade to Ext4. NOTE: File system configuration and management are out of the scope of this document. Mounting iSCSI File Systems When configuring /etc/fstab to automatically mount iSCSI file systems, verify the following: ● Enable Netfs NOTE: The command may change depending on the Linux release that you are using. # systemctl enable remote-fs.target # systemctl start remote-fs.target ● If you are not using LVM, edit the /etc/fstab file to mount the file systems automatically when the system boots. ● On Red Hat Enterprise Linux, the _netdev option should be used to indicate that the file system must mount automatically. The example below demonstrates a configuration entry with the _netdev option: #device mount point FS Options Backup fsck /dev/mapper/diskname /mnt/vol1 ext4 _netdev 0 2 If the file system being mounted exists directly on the device (does not use LVM), it is recommended to use labels, as shown in the example above. For information, see RedHat Knowledge Article 3889 (How can I mount iSCSI devices...). If you still experience issues, see RedHat Knowledge Article 22993 (Why aren't remote filesystems...) for additional troubleshooting steps. ● On SUSE Linux 11 and later, the nofail option should be used to indicate that the file system must mount automatically. The example below demonstrates a configuration entry with the nofail option: /dev/mapper/diskname /mnt/vol1 ext4 rw,nofail 0 2 Host Configuration for Linux 69

  • 1
  • 2
  • 3
  • 4
  • 5
  • 6
  • 7
  • 8
  • 9
  • 10
  • 11
  • 12
  • 13
  • 14
  • 15
  • 16
  • 17
  • 18
  • 19
  • 20
  • 21
  • 22
  • 23
  • 24
  • 25
  • 26
  • 27
  • 28
  • 29
  • 30
  • 31
  • 32
  • 33
  • 34
  • 35
  • 36
  • 37
  • 38
  • 39
  • 40
  • 41
  • 42
  • 43
  • 44
  • 45
  • 46
  • 47
  • 48
  • 49
  • 50
  • 51
  • 52
  • 53
  • 54
  • 55
  • 56
  • 57
  • 58
  • 59
  • 60
  • 61
  • 62
  • 63
  • 64
  • 65
  • 66
  • 67
  • 68
  • 69
  • 70
  • 71
  • 72
  • 73
  • 74
  • 75
  • 76
  • 77
  • 78
  • 79
  • 80
  • 81
  • 82
  • 83
  • 84
  • 85
  • 86
  • 87
  • 88
  • 89
  • 90
  • 91
  • 92
  • 93
in memeory only, until you decide to write them. After that, of course, the previous
content won't be recoverable.
Warning: invalid flag 0x0000 of partition table 4 will be corrected by w(rite)
Command (m for help): p
Disk /dev/mapper/3514f0c5b12a00004: 1649.3 GB, 1649267441664 bytes
255 heads, 63 sectors/track, 200512 cylinders, total 3221225472 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes I/O size
(minimum/optimal): 16384 bytes / 65536 bytes Disk identifier: 0x12d4e90c
Device Boot
Start
End
Blocks
Id
System
In this mode, rather than using "cylinders" for creating partitions, the
fdisk
command uses sectors, which are a direct mapping
to the LBA space of the cluster. Thus, to verify that the partition is aligned, simply verify that the starting sector number is a
multiple of 16 (16 sectors, at 512 bytes each, is 8 KB). The
fdisk
command defaults to a starting sector for the first partition
of 2048, which is divisible by 16, and thus is correctly assigned.
Creating a File System
When creating a file system with PowerStore cluster storage, use its default block size, and disable UNMAP during creation.
It is recommended to create the file system using its default block size (using a non-default block size may lead to unexpected
behavior). See your operating system and file system documentation.
NOTE:
Creating a file system with UNMAP enabled on a host connected to PowerStore may result in an increased amount
of write I/Os to the storage subsystem. It is highly recommended to disable UNMAP during file system creation.
To disable UNMAP during file system creation:
●
When creating a file system using the
mke2fs
command - Use the
"-E nodiscard"
parameter.
●
When creating a file system using the
mkfs.xfs
command - Use the
"-K"
parameter.
For a more efficient data utilization and better performance, use Ext4 file system with PowerStore cluster storage instead of
Ext3. For details about converting to Ext4 file system (from either Ext3 or Ext2), See
Upgrade to Ext4
.
NOTE:
File system configuration and management are out of the scope of this document.
Mounting iSCSI File Systems
When configuring
/etc/fstab
to automatically mount iSCSI file systems, verify the following:
●
Enable Netfs
NOTE:
The command may change depending on the Linux release that you are using.
# systemctl enable
remote-fs.target
# systemctl start
remote-fs.target
●
If you are not using LVM, edit the
/etc/fstab
file to mount the file systems automatically when the system boots.
●
On Red Hat Enterprise Linux, the
_netdev
option should be used to indicate that the file system must mount automatically.
The example below demonstrates a configuration entry with the
_netdev
option:
#device
mount point
FS
Options Backup
fsck
/dev/mapper/diskname /mnt/vol1
ext4
_netdev
0
2
If the file system being mounted exists directly on the device (does not use LVM), it is recommended to use labels, as shown
in the example above. For information, see
RedHat Knowledge Article 3889 (How can I mount iSCSI devices...)
. If you still
experience issues, see
RedHat Knowledge Article 22993 (Why aren't remote filesystems...)
for additional troubleshooting
steps.
●
On SUSE Linux 11 and later, the
nofail
option should be used to indicate that the file system must mount automatically.
The example below demonstrates a configuration entry with the
nofail
option:
/dev/mapper/diskname /mnt/vol1 ext4 rw,nofail 0 2
Host Configuration for Linux
69