AWS Storage Gateway User Guide
Your Cached Gateway is Unreachable
And You Want to Recover Your Data
For cached volumes, if the AWS Storage Gateway console indicates that your volume has a status of
IRRECOVERABLE, you can no longer use this volume. If there is data on the volume, you can create a
snapshot of the volume and then recover your data from the snapshot or you can clone the volume
from the last recovery point. You can delete the volume after you have recovered your data. For more
information, see
Your Cached Gateway is Unreachable And You Want to Recover Your Data (p. 332)
For stored volumes, you can create a new volume from the disk that was used to create the irrecoverable
volume. For more information, see
. For information about volume status, see
Understanding Volume Statuses and Transitions (p. 171)
.
Your Cached Gateway is Unreachable And You Want
to Recover Your Data
When your gateway becomes unreachable (such as when you shut it down), you have the option of either
creating a snapshot from a volume recovery point and using that snapshot, or cloning a new volume
from the last recovery point for an existing volume. Cloning from a volume recovery point is faster and
more cost effective than creating a snapshot. For more information about cloning a volume, see
.
AWS Storage Gateway provides recovery points for each volume in a cached volume gateway
architecture. A
volume recovery point
is a point in time at which all data of the volume is consistent and
from which you can create a snapshot or clone a volume.
The Console Says That Your Volume Has PASS
THROUGH Status
In some cases, the AWS Storage Gateway console might indicate that your volume has a status of
PASSTHROUGH. A volume can have PASSTHROUGH status for several reasons. Some reasons require
action, and some do not.
An example of when you should take action if your volume has the PASS THROUGH status is when
your gateway has run out of upload buffer space. To verify if your upload buffer was exceeded in the
past, you can view the
UploadBufferPercentUsed
metric in the Amazon CloudWatch console; for
more information, see
Monitoring the Upload Buffer (p. 196)
. If your gateway has the PASS THROUGH
status because it has run out of upload buffer space, you should allocate more upload buffer space to
your gateway. Adding more buffer space will cause your volume to transition from PASS THROUGH to
BOOTSTRAPPING to AVAILABLE automatically. While the volume has the BOOTSTRAPPING status, the
gateway reads data off the volume's disk, uploads this data to Amazon S3, and catches up as needed.
When the gateway has caught up and saved the volume data to Amazon S3, the volume status becomes
AVAILABLE and snapshots can be started again. Note that when your volume has the PASS THROUGH
or BOOTSTRAPPING status, you can continue to read and write data from the volume disk. For more
information about adding more upload buffer space, see
Determining the Size of Upload Buffer to
To take action before the upload buffer is exceeded, you can set a threshold alarm on a gateway's upload
buffer. For more information, see
To set an upper threshold alarm for a gateway's upload buffer (p. 197)
.
In contrast, an example of not needing to take action when a volume has the PASS THROUGH status is
when the volume is waiting to be bootstrapped because another volume is currently being bootstrapped.
The gateway bootstraps volumes one at a time.
Infrequently, the PASS THROUGH status can indicate that a disk allocated for an upload buffer has failed.
In this is the case, you should remove the disk. For more information, see
. For
information about volume status, see
Understanding Volume Statuses and Transitions (p. 171)
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