Archive
HP Lefthand VSA minimum memory requirements
These week I’ve trying to stretch the virtualization resources of my homelab as much as possible. In my obsession to run as many VMs as possible I decided to lower the memory of some of them, including my storage appliances.
My VSAs are configured with various amounts of RAM ranging from 384MB to 1GB. I took the one I have in my laptop for demo purposes, powered it off, set the RAM to 256MB and fired it up again.
The VSA seemed to start without any problems and from the console everything looked fine.
I started the CMC and quickly noticed that something was wrong, the status of the storage server was “offline”.
I then looked into the alerts area and found one saying that there was not enough ram to start the configured features.
OK then, the VSA doesn’t work with 256MB of RAM; so which value is the minimum required in order to run the storage services?
After looking into several docs I found the answer in the P4000 Quick Start VSA user guide. The minimum amount of RAM required is 384MB for the laptop version and 1GB for the ESX version. Also in the VSA Install and Configure Guide, that comes with the VSA, the following values are provided for the ESX version and for the new Hyper-V version:
- <500GB to 4.5TB – 1GB of RAM
- 4.5TB to 9TB – 2GB of RAM
- 9TB to 10TB – 3GB of RAM
After that I configured again the VSA with 384MB and the problem was fixed and the alarm disappeared.
Juanma.
Enabling the vSphere Web Access
If you are in the virtualization business you’ll probably know that since the release of vSphere back in 2009 the web access the ESX servers has been disabled by default. I really never minded about this, I still have nightmares with the awful and useless web interface of the ESX3, and to be sincere who needs a web access when you have SSH access, PowerCLI and the almighty vSphere Client.
But recently I found myself only with a Linux machine and no remote access to the vCenter Server. With a so limited range of resources I decided to try the web access but I had to enable it.
The first step is to log into the host via SSH. Once you are inside the ESX and from a root shell execute the following command to start the service.
Now you can point your web browser to http://<esx_ip_address>/ui and login as root, you will note that the interface is pretty much the same as in VMware Server 2.0.
After that I wanted to make the change permanent and like in any normal RedHat Linux server I issued the classic chkconfig command.
[root@esx41-01 ~]# chkconfig vmware-webAccess on
I thought that everything was done, nothing so far from the reality, after a reboot of the server the Web Access was gone.
At that point I no longer needed to access the ESX through the web so I did not spent more time with this; but later with one of my ESX servers at home I finally found how to permanently enable the Web Access.
From the vSphere Client go to the configuration tab of the ESX host and edit the Security Profile from the Software area. The pop-up window will show a list of services, look for the web access and check it.
If you now change to a SSH session and ask for the status of the service, will see the service started and enabled.
Reboot the server, if you can of course ;-), and you’ll see that the changes are permanent.
Juanma.
LVM and file system basics in HP-UX & Linux
Now that my daily work is more focused on Linux I found myself performing the same basic administration tasks in Linux that I’m used to do in HP-UX. Because of that I thought that a post explaining how the same basic file system and volume management operations are done in both operative systems was necessary, hope you like it :-)
This is going to be a very basic post intended only as a reference for myself and any other Sysadmin coming from either Linux or HP-UX that wants to know how things are done in the other side. Of course this post is no substitute of the official documentation and the corresponding man pages.
I used Red Hat Enterprise Linux 5.5 as the Linux version and 11iv3 as the HP-UX version.
The follwing topics will covered:
- Volume group creation.
- Logical volume operations.
- File system operations.
Volume group creation
Physical volume and volume group creation are the most basic tasks in LVM, both in Linux and HP-UX, but although command syntax is quite similar in both operative systems the whole process differs in many ways.
- HP-UX:
The example used is valid to 11iv2 and 11iv3 HP-UX versions, with the exception of the persistent DSFs you will have to substitute them for the corresponding legacy devices used in 11iv2.
First create the physical volumes.
root@hp-ux:/# pvcreate -f /dev/rdisk/disk10 Physical volume "/dev/rdisk/disk10" has been successfully created. root@hp-ux:/# root@hp-ux:/# pvcreate -f /dev/rdisk/disk11 Physical volume "/dev/rdisk/disk11" has been successfully created. root@hp-ux:/#
In /dev create a directory named as the new volume group, change the ownership to root:root and the permissions ot 755.
root@hp-ux:/# mkdir -p /dev/vg_new root@hp-ux:/# chown root:root /dev/vg_new root@hp-ux:/# chmod 755 /dev/vg_new
Go into the VG subdirectory and create the group device special file. For the Linux guys, in HP-UX each volume group must have a group device special file under its subdirectory in /dev. This group DSF is created with the mknod command, like any other DSFs the group file must have a major and a minor number.
For LVM 1.0 volume groups the major number must be 64 and for the LVM 2.0 one must be 128. Regarding the minor number, the first two digits will uniquely identify the volume group and the remaining digits must be 0000. In the below example we’re creating a 1.0 volume group.
root@hp-ux:/dev/vg_new# mknod group c 64 0x010000
Change the ownership to root:sys and the permissions to 640.
root@hp-ux:/dev/vg_new# chown root:sys group root@hp-ux:/dev/vg_new# chmod 640 group
And create the volume group with the vgcreate command, the arguments passed are the two physical volumes previously created and the size in megabytes of the physical extent. The last one is optional and if is not provided the default of 4MB will be automatically set.
root@hp-ux:/# vgcreate -s 16 vg_new /dev/disk/disk10 /dev/disk/disk11 Volume group "/dev/vg_new" has been successfully created. Volume Group configuration for /dev/vg_new has been saved in /etc/lvmconf/vg_new.conf root@hp-ux:/# root@hp-ux:/# vgdisplay -v vg_new --- Volume groups --- VG Name /dev/vg_new VG Write Access read/write VG Status available Max LV 255 Cur LV 0 Open LV 0 Max PV 16 Cur PV 2 Act PV 2 Max PE per PV 6000 VGDA 2 PE Size (Mbytes) 16 Total PE 26 Alloc PE 0 Free PE 26 Total PVG 0 Total Spare PVs 0 Total Spare PVs in use 0 --- Physical volumes --- PV Name /dev/disk/disk10 PV Status available Total PE 13 Free PE 13 Autoswitch On PV Name /dev/disk/disk11 PV Status available Total PE 13 Free PE 13 Autoswitch On root@hp-ux:/#
- Linux:
Create the physical volumes. Here it is where the first difference appears. In HP-UX a physical volume is composed by a whole disk, with the exception of boot disks in Itanium systems, but in Linux a physical volume can be a whole disk or a partition.
For the whole disk the process is pretty much the same as in HP-UX.
[root@rhel /]# pvcreate -f /dev/sdb Physical volume "/dev/sdb" successfully created [root@rhel /]# pvdisplay /dev/sdb "/dev/sdb" is a new physical volume of "204.00 MB" --- NEW Physical volume --- PV Name /dev/sdb VG Name PV Size 204.00 MB Allocatable NO PE Size (KByte) 0 Total PE 0 Free PE 0 Allocated PE 0 PV UUID Ngyz7I-Z2hL-8R3b-hzA3-qIVc-tZuY-DbCBYn [root@rhel /]#
If you decide to use partitions for the PVs the first, and obvious, thing to do is partition the disk. To setup the disk we’ll use the fdisk tool, following is an example session:
[root@rhel /]# fdisk /dev/sdc Command (m for help): n Command action e extended p primary partition (1-4) p Partition number (1-4): 1 First cylinder (1-204, default 1): Using default value 1 Last cylinder or +size or +sizeM or +sizeK (1-204, default 204): Using default value 204 Command (m for help): t Selected partition 1 Hex code (type L to list codes): 8e Changed system type of partition 1 to 8e (Linux LVM) Command (m for help): p Disk /dev/sdc: 213 MB, 213909504 bytes 64 heads, 32 sectors/track, 204 cylinders Units = cylinders of 2048 * 512 = 1048576 bytes Device Boot Start End Blocks Id System /dev/sdc1 1 204 208880 8e Linux LVM Command (m for help): w The partition table has been altered! Calling ioctl() to re-read partition table. Syncing disks. [root@rhel /]#
To explain the session first a new partition is created with the command n and the size of the partition is set (in this particular case we are using the whole disk); then we must change the partition type, which by default is set to Linux, to Linux LVM and to do that we use the command t and issue 8e as the corresponding hexadecimal code, the available values for the partition types can be shown by typing L.
Command (m for help): t Selected partition 1 Hex code (type L to list codes): L 0 Empty 1e Hidden W95 FAT1 80 Old Minix bf Solaris 1 FAT12 24 NEC DOS 81 Minix / old Lin c1 DRDOS/sec (FAT- 2 XENIX root 39 Plan 9 82 Linux swap / So c4 DRDOS/sec (FAT- 3 XENIX usr 3c PartitionMagic 83 Linux c6 DRDOS/sec (FAT- 4 FAT16 <32M 40 Venix 80286 84 OS/2 hidden C: c7 Syrinx 5 Extended 41 PPC PReP Boot 85 Linux extended da Non-FS data 6 FAT16 42 SFS 86 NTFS volume set db CP/M / CTOS / . 7 HPFS/NTFS 4d QNX4.x 87 NTFS volume set de Dell Utility 8 AIX 4e QNX4.x 2nd part 88 Linux plaintext df BootIt 9 AIX bootable 4f QNX4.x 3rd part 8e Linux LVM e1 DOS access a OS/2 Boot Manag 50 OnTrack DM 93 Amoeba e3 DOS R/O b W95 FAT32 51 OnTrack DM6 Aux 94 Amoeba BBT e4 SpeedStor c W95 FAT32 (LBA) 52 CP/M 9f BSD/OS eb BeOS fs e W95 FAT16 (LBA) 53 OnTrack DM6 Aux a0 IBM Thinkpad hi ee EFI GPT f W95 Ext'd (LBA) 54 OnTrackDM6 a5 FreeBSD ef EFI (FAT-12/16/ 10 OPUS 55 EZ-Drive a6 OpenBSD f0 Linux/PA-RISC b 11 Hidden FAT12 56 Golden Bow a7 NeXTSTEP f1 SpeedStor 12 Compaq diagnost 5c Priam Edisk a8 Darwin UFS f4 SpeedStor 14 Hidden FAT16 <3 61 SpeedStor a9 NetBSD f2 DOS secondary 16 Hidden FAT16 63 GNU HURD or Sys ab Darwin boot fb VMware VMFS 17 Hidden HPFS/NTF 64 Novell Netware b7 BSDI fs fc VMware VMKCORE 18 AST SmartSleep 65 Novell Netware b8 BSDI swap fd Linux raid auto 1b Hidden W95 FAT3 70 DiskSecure Mult bb Boot Wizard hid fe LANstep 1c Hidden W95 FAT3 75 PC/IX be Solaris boot ff BBT Hex code (type L to list codes):
The changes are written with w.
Once the partitions are correctly created, setup the physical volumes.
[root@rhel /]# pvcreate -f /dev/sdc1 Physical volume "/dev/sdc1" successfully created [root@rhel /]# pvcreate -f /dev/sdd1 Physical volume "/dev/sdd1" successfully created [root@rhel /]# [root@rhel /]# pvs PV VG Fmt Attr PSize PFree /dev/sda2 sysvg lvm2 a- 19.88G 0 /dev/sdb lvm2 -- 204.00M 204.00M /dev/sdc1 lvm2 -- 203.98M 203.98M /dev/sdd1 lvm2 -- 203.98M 203.98M [root@rhel /]#
Now that the PVs are created we can proceed with the volume group creation.
[root@rhel /]# vgcreate vg_new /dev/sdc1 /dev/sdd1 Volume group "vg_new" successfully created [root@rhel /]# vgdisplay -v vg_new Using volume group(s) on command line Finding volume group "vg_new" /dev/hdc: open failed: No medium found --- Volume group --- VG Name vg_new System ID Format lvm2 Metadata Areas 2 Metadata Sequence No 1 VG Access read/write VG Status resizable MAX LV 0 Cur LV 0 Open LV 0 Max PV 0 Cur PV 2 Act PV 2 VG Size 400.00 MB PE Size 4.00 MB Total PE 100 Alloc PE / Size 0 / 0 Free PE / Size 100 / 400.00 MB VG UUID lvrrnt-sHbo-eC8j-kC53-Mm5Z-IDDR-RJJtDr --- Physical volumes --- PV Name /dev/sdc1 PV UUID kD0jhk-ws8A-ke3L-a7nd-QucS-SAbH-BrmH28 PV Status allocatable Total PE / Free PE 50 / 50 PV Name /dev/sdd1 PV UUID ZP2bLy-FxR3-gYn9-3Dy1-Llgk-6mFI-1iJvTm PV Status allocatable Total PE / Free PE 50 / 50 [root@rhel /]#
As you could see the process in Linux is slightly simple than in HP-UX.
Logical volume operations
In this part we will see how to create a logical volume, extend this LV and then remove it from the system.
- HP-UX:
The logical volume creation can be done with the lvcreate command. With the -L option we can specify the size in MB of the new lvol, if -l is used instead the size must be provided in logical extents.
root@hp-ux:/# lvcreate -n lvol_test -L 256 vg_new Logical volume "/dev/vg_new/lvol_test_S2" has been successfully created with character device "/dev/vg_new/rlvol_test_S2". Logical volume "/dev/vg_new/lvol_test_S2" has been successfully extended. Volume Group configuration for /dev/vg_new has been saved in /etc/lvmconf/vg_new.conf root@hp-ux:~# lvdisplay /dev/vg_new/lvol_test --- Logical volumes --- LV Name /dev/vg_new/lvol_test VG Name /dev/vg_new LV Permission read/write LV Status available/syncd Mirror copies 0 Consistency Recovery MWC Schedule parallel LV Size (Mbytes) 256 Current LE 16 Allocated PE 16 Stripes 0 Stripe Size (Kbytes) 0 Bad block on Allocation strict IO Timeout (Seconds) default root@hp-ux:/#
Extend a volume. Of course the first prerequisite to extend a volume is to have enough free physical extends in the volume group.
root@hp-ux:~# lvextend -L 384 /dev/vg_new/lvol_test Logical volume "/dev/vg_new/lvol_test" has been successfully extended. Volume Group configuration for /dev/vg_new has been saved in /etc/lvmconf/vg_new.conf root@hp-ux:~# root@hp-ux:~# lvdisplay /dev/vg_new/lvol_test --- Logical volumes --- LV Name /dev/vg_new/lvol_test VG Name /dev/vg_new LV Permission read/write LV Status available/syncd Mirror copies 0 Consistency Recovery MWC Schedule parallel LV Size (Mbytes) 384 Current LE 24 Allocated PE 24 Stripes 0 Stripe Size (Kbytes) 0 Bad block on Allocation strict IO Timeout (Seconds) default root@hp-ux:/#
The final step of this part is to remove the logical volume.
root@hp-ux:/# lvremove /dev/vg_new/lvol_test The logical volume "/dev/vg_new/lvol_test" is not empty; do you really want to delete the logical volume (y/n) : y Logical volume "/dev/vg_new/lvol_test" has been successfully removed. Volume Group configuration for /dev/vg_new has been saved in /etc/lvmconf/vg_new.conf root@hp-ux:/#
- Linux:
Create the logical volume with the lvcreate command, the most basic options (-L, -l, -n) are the same as in HP-UX.
[root@rhel /]# lvcreate -n lv_test -L 256 vg_new Logical volume "lv_test" created [root@rhel /]# lvdisplay /dev/vg_new/lv_test --- Logical volume --- LV Name /dev/vg_new/lv_test VG Name vg_new LV UUID m5G2vT-dsE1-CycS-BMYR-3MYZ-4y8O-Mx04B8 LV Write Access read/write LV Status available # open 0 LV Size 256.00 MB Current LE 16 Segments 2 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:6 [root@rhel /]#
Now extend the logical volume to 384 megabytes as we did in HP-UX.
[root@rhel /]# lvextend -L 384 /dev/vg_new/lv_test Extending logical volume lv_test to 384.00 MB Logical volume lv_test successfully resized [root@rhel /]# [root@rhel /]# lvdisplay /dev/vg_new/lv_test --- Logical volume --- LV Name /dev/vg_new/lv_test VG Name vg_new LV UUID m5G2vT-dsE1-CycS-BMYR-3MYZ-4y8O-Mx04B8 LV Write Access read/write LV Status available # open 0 LV Size 384.00 MB Current LE 24 Segments 2 Allocation inherit Read ahead sectors auto - currently set to 256 Block device 253:6 [root@rhel /]#
Remove a volume from the system, like creation and extension is a very straight forward process that can be done with one command.
[root@rhel /]# lvremove /dev/vg_new/lv_test Do you really want to remove active logical volume lv_test? [y/n]: y Logical volume "lv_test" successfully removed [root@rhel /]#
Unlike the volume group section, the basic logical operations are performed in almost the same way in both operative systems. Of course if you want to perform mirroring the differences are bigger, but I will leave that for a future post.
File system operations
The final section of the post is about the basic file system operation, we are going to create a file system on the logical volume of the previous section and later to extend it, including this time the volume group extension.
- HP-UX:
Creating the file system with the newfs command.
root@hp-ux:/# newfs -F vxfs -o largefiles /dev/vg_new/rlvol_test version 7 layout 393216 sectors, 393216 blocks of size 1024, log size 1024 blocks largefiles supported root@hp-ux:/#
Create the mount point and mount the filesystem
root@hp-ux:/# mkdir /data root@hp-ux:/# mount /dev/vg_new/lvol_test /data
Filesystem extension, in the current section we are going to suppose that the volume group has not enough physical extension to accommodate the new size of the /data file system.
After we create a new physical volume in the disk12 we are going to extend the vg_new VG.
root@hp-ux:/# vgextend vg_new /dev/disk/disk12 Volume group "vg_new" has been successfully extended. Volume Group configuration for /dev/vg_new has been saved in /etc/lvmconf/vg_new.conf root@hp-ux:/# root@hp-ux:/# vgdisplay -v vg_new --- Volume groups --- VG Name /dev/vg_new VG Write Access read/write VG Status available Max LV 255 Cur LV 0 Open LV 0 Max PV 16 Cur PV 2 Act PV 2 Max PE per PV 6000 VGDA 2 PE Size (Mbytes) 16 Total PE 39 Alloc PE 24 Free PE 15 Total PVG 0 Total Spare PVs 0 Total Spare PVs in use 0 --- Logical volumes --- LV Name /dev/vg_mir/lv_sql LV Status available/syncd LV Size (Mbytes) 384 Current LE 24 Allocated PE 24 Used PV 2 --- Physical volumes --- PV Name /dev/disk/disk10 PV Status available Total PE 13 Free PE 13 Autoswitch On PV Name /dev/disk/disk11 PV Status available Total PE 13 Free PE 13 Autoswitch On PV Name /dev/disk/disk12 PV Status available Total PE 13 Free PE 13 Autoswitch On root@hp-ux:/#
The next part is to extend the logical volume just as we did in the logical volume operations section.
root@hp-ux:/# lvextend -L 512 /dev/vg_new/lvol_test Logical volume "/dev/vg_new/lvol_test" has been successfully extended. Volume Group configuration for /dev/vg_new has been saved in /etc/lvmconf/vg_new.conf root@hp-ux:~#
And finally the most creepy part of the part of the process, extending the file system. To be capable of extending a mounted filesystem in HP-UX the OnlineJFS bundle must be installed.
Use the command fsadm and with the -b option issue the new size in KB as the argument, in the example we want to extend to 512MB, in KB is 524288.
root@hp-ux:/# fsadm -F vxfs -b 524288 /data
vxfs fsadm: V-3-23585: /dev/vg00/rlvol5 is currently 7731200 sectors - size will be increased
root#hp-ux:/#
root@hp-ux:/# bdf /data
Filesystem kbytes used avail %used Mounted on
/dev/vg_new/lvol_test
524288 5243 524288 1% /data
root@hp-ux:/#
- Linux:
Here in the filesystem part is where the commands are completely different to HP-UX. In Linux the most common file system types are ext2 and ext3, although others like ext4 or reiserfs are supported.
To create an ext3 file system issue the command mkfs.ext3 using the logical volume to create the file system on as the argument.
[root@rhel ~]# mkfs.ext3 /dev/vg_new/lv_test
mke2fs 1.39 (29-May-2006)
Filesystem label=
OS type: Linux
Block size=1024 (log=0)
Fragment size=1024 (log=0)
98304 inodes, 393216 blocks
19660 blocks (5.00%) reserved for the super user
First data block=1
Maximum filesystem blocks=67633152
48 block groups
8192 blocks per group, 8192 fragments per group
2048 inodes per group
Superblock backups stored on blocks:
8193, 24577, 40961, 57345, 73729, 204801, 221185
Writing inode tables: done
Creating journal (8192 blocks): done
Writing superblocks and filesystem accounting information: done
This filesystem will be automatically checked every 35 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
[root@rhel ~]#
As in HP-UX create the mount point and mount the file system.
[root@rhel ~]# mkdir /data
[root@rhel ~]# mount /dev/vg_new/lv_test /data
[root@rhel ~]# df -h /data
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/vg_new-lv_test
372M 11M 343M 3% /data
[root@rhel ~]#
The final part of the section is the file system extension, as we did in the HP-UX part the first task is to extend the volume group.
[root@rhel ~]# vgextend vg_new /dev/sde1
Volume group "vg_new" successfully extended
[root@rhel ~]# vgdisplay -v vg_new
Using volume group(s) on command line
Finding volume group "vg_new"
--- Volume group ---
VG Name vg_new
System ID
Format lvm2
Metadata Areas 3
Metadata Sequence No 9
VG Access read/write
VG Status resizable
MAX LV 0
Cur LV 1
Open LV 1
Max PV 0
Cur PV 3
Act PV 3
VG Size 576.00 MB
PE Size 16.00 MB
Total PE 36
Alloc PE / Size 24 / 384.00 MB
Free PE / Size 12 / 192.00 MB
VG UUID u32c0h-BPGN-HixT-IzsX-cNnC-EspO-xfweaI
--- Logical volume ---
LV Name /dev/vg_new/lv_test
VG Name vg_new
LV UUID ZtArMo-Pyyl-BDHX-9CZQ-uEAK-VDqG-t60xy4
LV Write Access read/write
LV Status available
# open 1
LV Size 384.00 MB
Current LE 24
Segments 2
Allocation inherit
Read ahead sectors auto
- currently set to 256
Block device 253:6
--- Physical volumes ---
PV Name /dev/sdc1
PV UUID kD0jhk-ws8A-ke3L-a7nd-QucS-SAbH-BrmH28
PV Status allocatable
Total PE / Free PE 12 / 0
PV Name /dev/sdd1
PV UUID ZP2bLy-FxR3-gYn9-3Dy1-Llgk-6mFI-1iJvTm
PV Status allocatable
Total PE / Free PE 12 / 0
PV Name /dev/sde1
PV UUID wbiNu5-csig-uwY7-y14y-3C8Q-oeN0-hAT49g
PV Status allocatable
Total PE / Free PE 12 / 12
[root@rhel ~]#
Extend the logical volume with lvextend.
[root@rhel ~]# lvextend -L 512 /dev/vg_new/lv_test Extending logical volume lv_test to 512.00 MB Logical volume lv_test successfully resized [root@rhel ~]# lvs LV VG Attr LSize Origin Snap% Move Log Copy% Convert lv_home sysvg -wi-ao 256.00M lv_root sysvg -wi-ao 5.84G lv_swap sysvg -wi-ao 1.00G lv_tmp sysvg -wi-ao 1.00G lv_usr sysvg -wi-ao 9.75G lv_var sysvg -wi-ao 2.03G lv_test vg_new -wi-ao 512.00M [root@rhel ~]#
Finally resize the file system, to do that use the resize2fs tool. Unlike in HP-UX with fsadm, that needs the new size as an argument in order to extend the file system, if you simply issue the logical volume as the argument the resize2fs utility will extend the file system to the maximum size available in the LV.
[root@rhel ~]# resize2fs /dev/vg_new/lv_test resize2fs 1.39 (29-May-2006) Filesystem at /dev/vg_new/lv_test is mounted on /data; on-line resizing required Performing an on-line resize of /dev/vg_new/lv_test to 524288 (1k) blocks. The filesystem on /dev/vg_new/lv_test is now 524288 blocks long. [root@rhel ~]#
And at this point we are done. Any comments are welcome as always :-)
Juanma.
