hello sir .... i want to say thanks to you .... i watched your videos on the last week of my scheduled exam date .... really helpfull ....i cleared the exam 😃
Very awesome series, this is really helpful. One question, giving the questions you have shown at the beginning, in the exam, should we create the physical volumes and VG before creating and extending LVs?
One Important Note. You can add a partition as Physical Volume as well. For example you have 3 disks /dev/sda /dev/sdb and /dev/sdc. All are for example 20GB in size. Disk /dev/sda has already 2 partitions /dev/sda1 and /dev/sda2 (Linux and Swap) running and occupied 15GB. Now you want to add the remaining space of /dev/sda 5GB to Physical Volume. In that case, create a partition on /dev/sda as /dev/sda3 (type should be Linux 83 or Linux LVM 8e no matters). Now create Physcial Volume of /dev/sda3, /dev/sdb and /dev/sdc or total 45GB (5 GB from /dev/sda using the partition you create and 20 GB from both /dev/sdb and /dev/sdc. pvcreate /dev/sda3 /dev/sdb /dev/sdc This scenario needed to be explained because sometimes in exam, they only provide a single Physical disk connected to the server and you will have to attempt Linux Partition, Linux Swap Partition and LVM questions on a single connected extra hard drive. In that case you will have to create Physical volume on partition rather than the Physical disk.
Thanks for the update..one more doubt please..when I tried to create lv for 1gb from 2gb volume space iam getting 2gb lv created saying it as "rounding up size to full extent" why I can't make this even if I run exact command
Ideally this should not happen..you should be able to create the LV of 1GB. The only chance is that the you have changed the logical extent size to 2Gb. kindly check
hello sir! now in my practice i want to create the physical extent of 8MB but since i had created a volume group from my physical volume, the volume group has a free space of 500.00m and i assumed, i may be wrong, that i dont need to create another volume group again as i have clipped all my disks into that physical volume which gave me the vg1....i have tried to create the 8mb from volume group vg1 where i have the free space but it doesnt seem to work..i there anything i am doing wrong? thank you
If you created a volume group with the default PE size (physical extent size of 4Mb) then you need to create a new volume group with the -s flag and manually specify the PE size (physical extent size to be 8Mb). You can check with vgdisplay. Then create the logical volume using lvcreate specify the -l (lower case l flag) so that you're telling LVM to use the physical extents and then specify 10 and it will work. It will create an 80 Mb LVM volume, because 10 physical extents sized at 8Mb each (8x10=80 Mb). If you create the Logical Volume with a Volume Group with the default PE size (4Mb). Then you will end up creating a 40 Mb LVM Volume, because 10 physical extents sized at 4Mb each (4x10=40 Mb). I hope this helps.
The path of your logical volume will be something like /dev/VG/LV wherr VG is the volume group that you created and LV is the logical volume that you want to extend
@@dextutor in Exam scenario how are disks assigned for these disk management tasks , any tips will be helpful will it be same as /dev/sdb format or it it will be assigned in different way ?
it doesn't matter what there name is..you just need to understand how to use the name..just use lsblk command and you will see the list of all disks. Then whatever name is assigned simply use it according tot he question
I have an RHCSA Prep Book, it is asking me to create 500Mib LVM, when I try to create one that is 500Mib, Centos is rounding it up to 504Mib. Am I going to get this question wrong on the exam?
@@dextutor Yes, the book asks me to create a 500Mib logical volume from a volume group of 8Mib extents. 500/8= 62.5, so Im still struggling to grasp if this is like a trick question or if I can just add a logical volume of 62.5 extents?
Thats the issue.. 8MB.. The logical volume will always be in multiples of Physical extent, so in this case multiples of 8. So to create a 500MB volume you can first change the extent size to 4MB or 10MB and then create the volume of 500MB
hello sir .... i want to say thanks to you .... i watched your videos on the last week of my scheduled exam date .... really helpfull ....i cleared the exam 😃
Thats great.. All the best for future
Here's a video to your success ruclips.net/video/athzPUkpLJg/видео.html
That was the clearest explanation i could find. thank you so much for this amazing lesson =)
Presentation : perfect.
Thanks
this is the best video about lvm I have found so far
Thanks..keep sharing
Thank you sir crystal clear explanation 🤝🤝🤝🤝
Keep watching
very good so natural you have a way to explaing things very calm and nice I like it
Thank you! 😃
Thankyou very much sir, its very clear now. what you have done is always appreciable
Thank You for your tutorials... I have cleared my RHCSA Exam.. It was really very helpful.
Thank you so much.. 😊😊
Congratulations
Hey, how was the exam? How long did you prepare for? Any tips?
Here's a video to your success ruclips.net/video/athzPUkpLJg/видео.html
Thank you so much for these videos, they are really helpful. You are a beast.
Amazing teaching sir...Thank you
Very awesome series, this is really helpful. One question, giving the questions you have shown at the beginning, in the exam, should we create the physical volumes and VG before creating and extending LVs?
Depends on the question. What is already given and what is being asked.
One Important Note.
You can add a partition as Physical Volume as well. For example you have 3 disks /dev/sda /dev/sdb and /dev/sdc. All are for example 20GB in size. Disk /dev/sda has already 2 partitions /dev/sda1 and /dev/sda2 (Linux and Swap) running and occupied 15GB. Now you want to add the remaining space of /dev/sda 5GB to Physical Volume. In that case, create a partition on /dev/sda as /dev/sda3 (type should be Linux 83 or Linux LVM 8e no matters).
Now create Physcial Volume of /dev/sda3, /dev/sdb and /dev/sdc or total 45GB (5 GB from /dev/sda using the partition you create and 20 GB from both /dev/sdb and /dev/sdc.
pvcreate /dev/sda3 /dev/sdb /dev/sdc
This scenario needed to be explained because sometimes in exam, they only provide a single Physical disk connected to the server and you will have to attempt Linux Partition, Linux Swap Partition and LVM questions on a single connected extra hard drive. In that case you will have to create Physical volume on partition rather than the Physical disk.
Thank you for the video, it's very easy to follow and understand. Does anyone know if these questions are still valid for the RHCSA exam in 2023?
Yes.. All valid
Hello brother your video are good please make full rhcsa exam video
Keep checking the channel. More videos are added
Hi without removing lv and vg can you modify 4mib blocks to 8mib blocks?
No because changing the extent size is possible only when we create volume group
Thanks for the update..one more doubt please..when I tried to create lv for 1gb from 2gb volume space iam getting 2gb lv created saying it as "rounding up size to full extent" why I can't make this even if I run exact command
Ideally this should not happen..you should be able to create the LV of 1GB. The only chance is that the you have changed the logical extent size to 2Gb. kindly check
is it required to mount it by the UUID for swap?
Yes.. Mounting must be done for all disk/partition management questions
@@dextutor swap can only be mounted using the UUID, correct? Thanks for the videos and quick reply.
You can use the partition path also
Do I have to format the Lvm with mkfs.xfs if I’m imputing the format in fstab and running mount -a ?
Yes
Sir exam m mention hota h kya ki kis disk pe se lvm bnana h kisse swap or kisse vdo?
Nope.. Wo apko decide karna hoga as per available disk size and question
hello sir! now in my practice i want to create the physical extent of 8MB but since i had created a volume group from my physical volume, the volume group has a free space of 500.00m and i assumed, i may be wrong, that i dont need to create another volume group again as i have clipped all my disks into that physical volume which gave me the vg1....i have tried to create the 8mb from volume group vg1 where i have the free space but it doesnt seem to work..i there anything i am doing wrong? thank you
If you created a volume group with the default PE size (physical extent size of 4Mb) then you need to create a new volume group with the -s flag and manually specify the PE size (physical extent size to be 8Mb). You can check with vgdisplay. Then create the logical volume using lvcreate specify the -l (lower case l flag) so that you're telling LVM to use the physical extents and then specify 10 and it will work. It will create an 80 Mb LVM volume, because 10 physical extents sized at 8Mb each (8x10=80 Mb).
If you create the Logical Volume with a Volume Group with the default PE size (4Mb).
Then you will end up creating a 40 Mb LVM Volume, because 10 physical extents sized at 4Mb each (4x10=40 Mb).
I hope this helps.
While extending the lvm i get message please specify a logical volume path ,Please assist where i am going wrong
The path of your logical volume will be something like /dev/VG/LV wherr VG is the volume group that you created and LV is the logical volume that you want to extend
@@dextutor in Exam scenario how are disks assigned for these disk management tasks , any tips will be helpful will it be same as /dev/sdb format or it it will be assigned in different way ?
it doesn't matter what there name is..you just need to understand how to use the name..just use lsblk command and you will see the list of all disks. Then whatever name is assigned simply use it according tot he question
I have an RHCSA Prep Book, it is asking me to create 500Mib LVM, when I try to create one that is 500Mib, Centos is rounding it up to 504Mib. Am I going to get this question wrong on the exam?
I suppose yes, it would be wrong. Check if you are doing everything correct. See if it is due to physical extent size.
@@dextutor Great thanks! Your videos have been a lot of help!
@@dextutor Yes, the book asks me to create a 500Mib logical volume from a volume group of 8Mib extents. 500/8= 62.5, so Im still struggling to grasp if this is like a trick question or if I can just add a logical volume of 62.5 extents?
Thats the issue.. 8MB.. The logical volume will always be in multiples of Physical extent, so in this case multiples of 8. So to create a 500MB volume you can first change the extent size to 4MB or 10MB and then create the volume of 500MB
@@dextutor Oh that is smart! Thanks.
Pls increase your font size
Good lord, there's a reason I hate the LVM topic