|
|
Sponsored Content
Operating Systems
Solaris
Understanding ZFS Snapshots - why will it utilize space ?
Post 303013453 by Peasant on Wednesday 21st of February 2018 02:08:33 PM
02-21-2018
Moderator
In a nutshell yes.
It is confusing a bit from user perspective,zfs used/usedsnap etc.
I would recommend reading about snapshots and COW in general.
Any tech that uses those, basically works on same principle.
Range is from filesystems (zfs,brtfs etc.) to enterprise storage systems with proprietary HW/SW.
Everything works the same way more or less.
Lets say blocks need to be modified due to write request.
Instead of overwriting blocks, zfs will write a change a new blocks, while old blocks will still contain old data, and that data will remain on disk until needed and is considered free.
This is what enables snapshots,clones, rollback etc. which is fundamental design of zfs filesystem/volume manager.
If there is a snapshot (pointers to old blocks at the time snapshot is taken), those will not be considered free but will remain unchanged (read the blog i posted, it is extremely good).
This is what enables snapshots,clones, rollback etc.
ZFS is a great and fairly complex product code wise with a lot of time and effort put into it.
One can only put a hat down to those SUN engineers behind it.
Those guys were ahead of their time.
Also, i must apologize upfront for information given in this post due to minor alcohol intoxication
This happens you know, when you are in automation business.
As a folks say here
'An idle mind is a devils workshop'
Regards
Peasant.
It is confusing a bit from user perspective,zfs used/usedsnap etc.
I would recommend reading about snapshots and COW in general.
Any tech that uses those, basically works on same principle.
Range is from filesystems (zfs,brtfs etc.) to enterprise storage systems with proprietary HW/SW.
Everything works the same way more or less.
Lets say blocks need to be modified due to write request.
Instead of overwriting blocks, zfs will write a change a new blocks, while old blocks will still contain old data, and that data will remain on disk until needed and is considered free.
This is what enables snapshots,clones, rollback etc. which is fundamental design of zfs filesystem/volume manager.
If there is a snapshot (pointers to old blocks at the time snapshot is taken), those will not be considered free but will remain unchanged (read the blog i posted, it is extremely good).
This is what enables snapshots,clones, rollback etc.
ZFS is a great and fairly complex product code wise with a lot of time and effort put into it.
One can only put a hat down to those SUN engineers behind it.
Those guys were ahead of their time.
Also, i must apologize upfront for information given in this post due to minor alcohol intoxication
This happens you know, when you are in automation business.
As a folks say here
'An idle mind is a devils workshop'
Regards
Peasant.
This User Gave Thanks to Peasant For This Post:
|
|
3 More Discussions You Might Find Interesting
1. Solaris
I have 2 hard disks ,one hard disk(40gb) completely for windows Os,and the other(120gb) for solaris Os.
In the second hard disk.I have utilised around 10gb for the solaris installation and also partitioned with the available 10gb space for the solaris x86 OS.
Now i need to utilise the... (8 Replies)
Discussion started by: jayaprakash
8 Replies
2. Solaris
I have a question regarding installing recommended patch clusters via ZFS snapshots. Someone wrote a pretty good blog about it here:
Initial Program Load: Live Upgrade to install the recommended patch cluster on a ZFS snapshot
The person's article is similar to what I've done in the past. ... (0 Replies)
Discussion started by: christr
0 Replies
3. Solaris
Hi,
I work as an Oracle Technical consultant (mainly DBA related), and I have used ZFS snapshots on previous projects which has helped me a great deal. I often take snapshots before doing some dev work, and then I can roll it back if I want to start again, or if it goes pear shaped!!
I have... (4 Replies)
Discussion started by: AndyG
4 Replies
LEARN ABOUT DEBIAN
install-solaris
install-solaris(1M) install-solaris(1M) NAME
install-solaris - install the Solaris operating system SYNOPSIS
install-solaris install-solaris invokes the Solaris Install program. Depending on graphical capability and available memory at the time of invocation, install-solaris invokes either a text-based installer or a graphical installer. The following minimum requirements for physical memory dictate which features are available during installation: For SPARC machines: 128 MB Minimum physical memory for all installation types 128 MB Minimum physical memory required for windowing system 384 MB Minimum physical memory required for graphical-based installation For x86 machines: 256 MB Minimum physical memory for all installation types 256 MB Minimum physical memory required for windowing system 512 MB Minimum physical memory required for graphical-based installation In some cases, even if the minimum physical memory is present, available virtual memory after system startup can limit the number of fea- tures available. install-solaris exists only on the Solaris installation media (CD or DVD) and should be invoked only from there. Refer to the for more details. install-solaris allows installation of the operating system onto any standalone system. install-solaris loads the software available on the installation media. Refer to the for disk space requirements. Refer to the for more information on the various menus and selections. See attributes(5) for descriptions of the following attributes: +-----------------------------+-----------------------------+ | ATTRIBUTE TYPE | ATTRIBUTE VALUE | +-----------------------------+-----------------------------+ |Availability |SUNWcdrom (Solaris instal- | | |lation media) | +-----------------------------+-----------------------------+ |Interface Stability |Evolving | +-----------------------------+-----------------------------+ pkginfo(1), install(1M), pkgadd(1M), attributes(5) It is advisable to exit install-solaris by means of the exit options in the install-solaris menus. 23 Sep 2005 install-solaris(1M)