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Backup and
Archiving to Disk
Deduplication and ExaGrid Systems Frequently Asked Questions
Customers and prospects often have questions
about data deduplication, ExaGrid's products, technology and the company itself.
A list of the most frequently asked questions and their answers is available
below.
You can click on the specific categories or
scroll down the page to find the information.
 Compatibility
Ease
of Use
Performance
Onsite
and Offsite Systems and Tape Elimination
Data
Growth and System Expansion
Maintenance
& Support
Company
Background
Compatibility
What backup applications does the ExaGrid
appliance work with?
ExaGrid works with the following backup
applications and environments:
- BakBone NetVault - 8.5 (available July,
2010)
- CA ARCServe - 11.5, 12.0, 12.5
- CommVault Simpana - 7.0, 8.0
- EMC Networker - 7.3, 7.4, 7.5, 7.6
- HP Data Protector - 6.x (available July,
2010)
- Microsoft SQL Dump - 2000, 2005, 2008
dumps
- Oracle Recovery Manager (RMAN)
- Symantec Backup Exec - 11D, 11.5, 12.0,
12.5, 2010/OST
- Symantec NetBackup - 6.0, 6.5.x, 7.0/OST
- Unix/Linux File System Data Dumps
- Vizioncore vRanger Pro - 3.x, 4.x
- VMware Backup - VMDK via supported backup
applications
and VMDK direct backups
What data can be backed up into an ExaGrid
appliance?
The ExaGrid system can be used with any data
that comes through the above listed backup applications. It doesn't matter if
the data is files, e-mail data, databases, etc. It also doesn't matter whether
it's coming from a disk local to the target, a NAS system, a SAN or a remote
office via replication or WAN acceleration. All types of data can be
effectively data-reduced with byte-level data deduplication.
How many copies of my backup data can I keep
on your system?
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If your backup schedule is to do: |
You can keep: |
- Weekly full backups of all data
(files, database, e-mail), plus
- Daily incremental backups of files,
plus
- Daily full backups of databases and
e-mail
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Up to 16 weeks worth of your weekly fulls plus 2 weeks of your dailies |
- Daily full backups of all of your data
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Up to 75 copies of your daily fulls |
The above numbers are based on a typical mix
of data with an industry average change rate of 2% per week at the byte level.
In other words, in any given week, your data changes an average of 2% through
normal business activities (files edits, file adds, file deletes, e-mail
traffic, and database transactions).
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Ease of Use
What do I need to change to make my backup
application work with ExaGrid?
No changes are required. All backup
applications support writing to disk in a number of ways; to a disk volume, to
a tape library, to a NAS share (Ethernet Network Attached Storage Share), or
backup jobs that write snapshots to disk. ExaGrid presents NAS shares to the
backup server. Existing backup jobs are simply redirected to write to the NAS
shares on ExaGrid. Your current backup jobs and schedule stay intact.
Does ExaGrid require special software on my
backup server or do I need to buy any additional software from my backup
vendor?
As long as you are using one of the backup
application versions listed above, then you have everything you need. ExaGrid
does not require any additional software. Your backup application has
everything it needs to write to disk.
How hard is it to set up?
You plug in a standard Gigabit Ethernet
connection between the backup server and the ExaGrid sytems, set up some
shares on it, point your existing backup jobs to the NAS shares and go. Set up
can be completed in a morning and backups can be sent to the ExaGrid system
that night.
Do you support backup servers running on
Windows, Linux and UNIX?
Yes, ExaGrid supports two protocols; CIFS for
Windows and NFS for Linux and UNIX.
Do I continue to use my backup application
user interface?
Yes, you set up backup jobs, rotations,
restore data, etc., as you do today. ExaGrid sits behind the backup server as
a disk-based backup storage repository.
Performance
Will my backup window shrink?
Yes, most customers report that their backup
window will drop from 30% to 80%. It is not uncommon to see a 10-hour backup
window drop to 5 hours or less. ExaGrid writes at the speed of disk as ExaGrid
does all of its compression and byte level data deduplication after the backup
job is completed. ExaGrid does not do any inline compression or deduplication.
This allows the backups to go as fast as the disk can write.
What level of compression and data
deduplication do you achieve?
ExaGrid compresses the most recent backup
file and keeps it in its entirety. Average compression is about 2 to 1, so a
1TB backup file would be stored as 500GB. All previous backup files are then
kept as the byte level changes only, which averages to about 2% of the data,
equating to about 20GB for every 1TB of data. This means that if you kept 20
weeks of backup retention, for 1 TB of primary data, the latest backup would
be stored as 500GB and the previous backups would be stored as 19 x 20GB (380
GB byte changes) or a total of 500GB + 380GB = 880GB. If you did not use
compression and byte-level data deduplication you would need 20TB of storage
space. In this example ExaGrid would use 880GB versus 20TB. This instance is
23 to 1 data reduction. Overall we see anywhere from 10 to 50:1 reduction in
disk consumption.
What happens to my restore speed if you
store byte level changes?
90% of restores come from the last backup as
this is the most up-to-date data. In this case ExaGrid is extremely fast as it
stores the last backup in its entirety. For the remaining 10% of restores
ExaGrid updates the last backup with the byte level changes from the version
requested. This happens very quickly as ExaGrid ships with Intel Quad-Core
XEON processors.
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Onsite &
Offsite Systems / Tape Elimination
Can I use an ExaGrid system onsite to eliminate
tape and still use tape for offsite?
Yes, your existing backup application will
write to ExaGrid for your standard nightly backups on Monday, Tuesday,
Wednesday, Thursday, Friday, etc. You can set up a backup job, in your
existing backup application, to make a copy from ExaGrid (NAS) through the
backup server to tape. All backup applications can make a copy from NAS to
tape. The benefit of using this feature already in your backup application is
that restores can be completed directly from tape without ExaGrid in the
middle.
Can I use ExaGrid for both onsite and
offsite and shut tape off?
Yes, in fact over half of ExaGrid's customers
have systems installed at more than one location and move byte level changes
offsite for long-term offsite retention and/or disaster recovery. ExaGrid
supports two site or multi-site topologies. Because ExaGrid only moves the
byte-level changes from the local site to an offsite system only about 1/50th
of the data has to traverse the WAN.
How much WAN bandwidth would I need between
ExaGrid Systems?
Typically, about 2% of the bytes change from
full backup to full backup. ExaGrid compares the two backups and only moves
the changes at the byte level. For every 1TB of primary data the byte level
changes would be about 20GB. Standard bandwidth math dictates that for 20GB of
data about 3mbps is needed to move the changes to the offsite location in less
than a day (about 18 hours). If the change rate is higher then additional
bandwidth would be required. Compare and contrast this to moving a full backup
and a 1TB full would take about 38 days to move across to the second site
which is why you only want to move the byte-level changes from one site to the
other.
How do I get the first full backup to the
offsite if I have limited bandwidth?
You bring both systems together in the same
data center to start and do a full into the primary system and then replicate
the full to the second system on the local network. From there the second
system is shipped to the offsite location. From that point forward only
changes at the byte level are replicated to the second site.
If only the changes are moved to the second
site do I have a complete backup on the offsite system?
The offsite system has the latest copy of the
full backup because each time ExaGrid replicates changes to the offsite it
updates the latest full with the changes. This creates an up to date full
backup on both sides with identical byte level changes for the previous
copies. Both the primary and offsite are identical in every way.
Can I install the offsite system at another
location and do backups into that location?
Yes, backups can be sent to the ExaGrid at
the primary site and at the offsite location. The byte level changes will
replicate from the primary site to the offsite system and the byte level
changes at the offsite will replicate to the primary site. In short, the
systems will both act as primary backup storage for the site where they are
located but will cross-protect each other as offsite backups.
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Data
Growth & System Expansion
What if my data grows or I decide to extend my
retention?
ExaGrid is a highly scalable solution.
ExaGrid ships with GRID computing software. As your data grows, you just plug
in another ExaGrid server and it virtualizes into the existing system. To the
backup server it just appears as a bigger system. The processor, memory and
disk storage "virtualize" to make a larger system. ExaGrid has a back channel
Gigabit Ethernet connection between servers for management and for load
balancing as ExaGrid will automatically load and capacity balance across
servers.
What if new drives or new processors ship,
can the old work with the new?
Yes, this is the power of GRID computing. You
can buy an ExaGrid server today and if you buy another ExaGrid in two years
and the processors and drives have improved the two systems will still
virtualize into each other as GRID computing works with different processors,
processor speeds, and different disks and disk sizes. For the first time
backup systems do not have to become obsolete as you go forward.
As I add more ExaGrid servers do the backups
slow down?
No. Each ExaGrid server comes with additional
Gigabit Ethernet connectivity, as well as on-board processor, memory and disk.
Therefore, each server comes equipped to handle the amount of data it is sized
for. Also, shares can be simply migrated from one server to another such that
the jobs can be spread across multiple servers in the GRID. ExaGrid tracks and
knows where all the data is in the GRID, as the GRID is seen as one large
virtualized system.
What size servers does ExaGrid have and can
they be mixed and matched in the GRID?
ExaGrid sizes servers to the primary data
(full backup). There are 6 building block configurations: 1TB of primary data,
2TB, 3TB, 4TB, 5TB, and 10TB. These servers can be asymmetrically added to the
GRID which means you can buy any of these servers, at any time, and plug them
into the GRID. If you have 12TB of primary data (full backup) you can put one
10TB and one 2TB ExaGrid servers in the GRID or you can put three 4TB ExaGrid
servers into the GRID.
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Maintenance & Support
What happens if a disk drive fails?
The ExaGrid system is configured with RAID6
plus a hot spare. Each ExaGrid server can survive 2 simultaneous drive
failures. The ExaGrid system will use the spare drive to start rebuilding
immediately. As long as you are on yearly maintenance all you have do is
notify ExaGrid and a new drive is sent to you (next business day). There is no
charge. Simply take out the old drive and insert the new one. The drives are
hot swappable so the system always stays in production.
What happens if a power supply fails?
ExaGrid ships with a redundant 3 component
power supply system. If a power supply module fails simply call ExaGrid and
the module will be sent the next business day. There is no charge. Simply
slide out the bad module and slide in the new one. The modules are hot
swappable so the system always stays in production. You must be on yearly
maintenance for this service.
What happens if a server fails (motherboard
failure)?
If you are on yearly maintenance ExaGrid will
send out a new server the next business day. There is no charge. You can take
the power supply modules and the drives and slide them into the new server.
When you turn on the server everything will be there because all of the
software configuration, data, etc. is on the drives.
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Company
Background
What does the name ExaGrid mean?
ExaGrid was founded to build a scalable
disk-based backup solution. There are terabytes, petabytes and exabytes of
data. ExaGrid allows a customer to scale using a GRID-based architecture so
ExaGrid took the Exa from exabyte and Grid from GRID computing to form the
company name ExaGrid.
How long has ExaGrid been in business?
ExaGrid was founded in 2002. The company
serves a large list of customers in a multitude of major industry sectors
around the world.
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