storage profile is a cusom one which allows writing to tier 2 and then tiers down to tier 3, as its for backups so over the weekend backups will run and needs tier 2 write speed but I then want it to go down to tier 3 quickly and stay there unless needed. Disbaled replays to see if hat would save space.
But it seems to be staying in tier 2?
What is the difference between volume space active and disk space active?
1. Compellent relies on replays to drive the tiering process. No replays, no tiering. Create a replay profile, even is the replay expires in 24 hours and you keep only one replay. You need it.
2.
Volume Space Active: What does the server see for storage or how big is the volume you created.
Disk Space Active: How much storage it takes to host the volume. For example, you can see at RAID10. 1.97TB is half of 3.93TB. At RAID 6 you see the disk cost for storage goes down dramatically.
Also, since no replays have occurred, all of your space is active. With a daily replay in place, your active space will be limited to the volume of writes that have occurred since the last replay. This can help you understand how your systems utilized storage and what your change rate it for data.
Yes, the 2.69 TB is the total current consumed by the volume out of the 2.8 TB you've configured for it. The total disk space of 4.83 TB is because since most of the data is R10, the total capacity is about 2X of the consumed space.
I would also recommend as the earlier person mentioned that you take at least 1 replay a day probably just before your Data Progression starts (defaults at 7 PM unless you've changed it), this way it'll assist helping the data to Tier between storage types. Depending on what code you are on, it'll do the R10 to R5 conversion for the data more quickly than the Data Progression cycle.
It may seem counter-intuitive but you will actually get space back to the system when it does the R10 to R5 conversion. Also you likely have space in that volume consuming Tier 3 R6-10 space either because at one point you told the Storage Profile to write directly there OR you actually ran out of space in Tier 2 and was forced to write the data in Tier 3. Setting up a Replay schedule for this volume will help to prevent Tier 2 from running out of space and aid in Tiering both by RAID types to give your system space back AND the Tier 2 to Tier 3 data progression.
Without replays the Compellent had no metadata on block activity or aging information. It takes a full 12 data progression cycles (12 days) to move data down to tier 3.
Blocks that are overridden will drop straight to tier 3.
So with data progression how it works is that it look at the data that is being access the most and will put that data on Tier 1 storage & will move all data that is not being access as often down to tier 2 & 3 storage. Now when you run a replay it takes a snapshot of the pages and marks them so that it can track which pages are changing. After about 10-15 days of taking replays & data progression running you will see that that your data will start to move to tier 2&3 storage. Now you might be thinking is there a way to change the timer for the data progression cycle to move the data faster and there is not.
Please let us know if you have any other questions.
piedthepiper
1 Rookie
•
85 Posts
0
July 22nd, 2015 07:00
Relay profile is set to none
storage profile is a cusom one which allows writing to tier 2 and then tiers down to tier 3, as its for backups so over the weekend backups will run and needs tier 2 write speed but I then want it to go down to tier 3 quickly and stay there unless needed. Disbaled replays to see if hat would save space.
But it seems to be staying in tier 2?
What is the difference between volume space active and disk space active?
OfficeGlen
6 Posts
1
July 22nd, 2015 08:00
1. Compellent relies on replays to drive the tiering process. No replays, no tiering. Create a replay profile, even is the replay expires in 24 hours and you keep only one replay. You need it.
2.
Volume Space Active: What does the server see for storage or how big is the volume you created.
Disk Space Active: How much storage it takes to host the volume. For example, you can see at RAID10. 1.97TB is half of 3.93TB. At RAID 6 you see the disk cost for storage goes down dramatically.
Also, since no replays have occurred, all of your space is active. With a daily replay in place, your active space will be limited to the volume of writes that have occurred since the last replay. This can help you understand how your systems utilized storage and what your change rate it for data.
Enjoy,
Glen
piedthepiper
1 Rookie
•
85 Posts
0
July 22nd, 2015 08:00
So with the above, I have disabled replays on this volume, why does it say replay size of over 2TB then? #confused
Volume space active, is what the esxihost sees
Disk Space acive = what compellen is using to host the volume.
So even though its a backup RDM I should create a relay to get data shifting down to tier 3?
piedthepiper
1 Rookie
•
85 Posts
0
July 22nd, 2015 09:00
2.69TB is the total volume size, so this is what the host/Vm (RDM) will see
4.83TB is the total disk space consumed by compellent for this volume?
BVienneau
115 Posts
1
July 22nd, 2015 10:00
Yes, the 2.69 TB is the total current consumed by the volume out of the 2.8 TB you've configured for it. The total disk space of 4.83 TB is because since most of the data is R10, the total capacity is about 2X of the consumed space.
I would also recommend as the earlier person mentioned that you take at least 1 replay a day probably just before your Data Progression starts (defaults at 7 PM unless you've changed it), this way it'll assist helping the data to Tier between storage types. Depending on what code you are on, it'll do the R10 to R5 conversion for the data more quickly than the Data Progression cycle.
It may seem counter-intuitive but you will actually get space back to the system when it does the R10 to R5 conversion. Also you likely have space in that volume consuming Tier 3 R6-10 space either because at one point you told the Storage Profile to write directly there OR you actually ran out of space in Tier 2 and was forced to write the data in Tier 3. Setting up a Replay schedule for this volume will help to prevent Tier 2 from running out of space and aid in Tiering both by RAID types to give your system space back AND the Tier 2 to Tier 3 data progression.
piedthepiper
1 Rookie
•
85 Posts
0
July 22nd, 2015 14:00
ah ok so take a replay at least once a day to make sure it tiers.
Why does it show a replay size of 2.69TB when replays are disabled? I am sure its something obvious, it just doesnt quite make sense
BVienneau
115 Posts
0
July 22nd, 2015 14:00
GUI just doesn't account for that people may not do Replays on a volume. We'll call it a GUI bug. :-)
piedthepiper
1 Rookie
•
85 Posts
0
July 23rd, 2015 03:00
ok so what I have done is I have moved it into the high rate of change replay profile, as hats where it was before and thats where everything is!
piedthepiper
1 Rookie
•
85 Posts
0
July 24th, 2015 02:00
I have created a replay at m last night and data is still in Tier 2? Just trying to get my head round it
OfficeGlen
6 Posts
0
July 24th, 2015 07:00
Without replays the Compellent had no metadata on block activity or aging information. It takes a full 12 data progression cycles (12 days) to move data down to tier 3.
Blocks that are overridden will drop straight to tier 3.
Here is a presentation deck that might help you. marketing.dell.com/.../03INFORM_1Day_in_the_Life_of_Compellent_Page.pdf
Good luck.
piedthepiper
1 Rookie
•
85 Posts
0
July 24th, 2015 08:00
Ah ok this makes much more sense to me! Thank you
piedthepiper
1 Rookie
•
85 Posts
0
July 24th, 2015 08:00
ahh 12 days to move down! I had no idea
Thank you for the slide deck!
DELL-Sam L
Moderator
•
7.9K Posts
•
21 Points
0
July 24th, 2015 08:00
Hello piedthepiper,
So with data progression how it works is that it look at the data that is being access the most and will put that data on Tier 1 storage & will move all data that is not being access as often down to tier 2 & 3 storage. Now when you run a replay it takes a snapshot of the pages and marks them so that it can track which pages are changing. After about 10-15 days of taking replays & data progression running you will see that that your data will start to move to tier 2&3 storage. Now you might be thinking is there a way to change the timer for the data progression cycle to move the data faster and there is not.
Please let us know if you have any other questions.