If your workloads need high performance, low latency, temporary storage,then consider using local solid-state drive (Local SSD) disks when you createyour compute instance. Local SSD disks are always-encrypted temporarysolid-state storage for Compute Engine. To learn about the other disksavailable in Compute Engine, seeChoose a disk type.

Local SSD disks are ideal when you need storage for any ofthe following use cases:

• Caches or storage for transient data
• Scratch processing space for high performance computing or data analytics
• Temporary data storage like for thetempdb system database for MicrosoftSQL Server

Local SSD disks offer superior I/O operations per second (IOPS), and very lowlatency compared to the persistent storage provided byGoogle Cloud Hyperdisk andPersistent Disk. This low latency isbecause Local SSD disks are physically attached to the server that hosts yourinstance. For this same reason, Local SSD disks canprovide only temporary storage.

Warning: Local SSD storage isnot automatically replicated andall data on the Local SSD may be lost if the instance stops or is terminatedfor any reason. SeeLocal SSD data persistence for details.

Because Local SSD is suitable only for temporary storage, you must store datathat isn't temporary or ephemeral in nature on a Hyperdiskor Persistent Disk volume.

To use Local SSD disks with a compute instance,add Local SSD disks when you create the instance.You can't add Local SSD disks to an instance after you create it.

Limitations

Local SSD has the following limitations:

• You can't use Local SSD disks with virtual machine (VM) instances that useshared-core machinetypes.

• Not all machine series and machine types support Local SSD. For a full list ofmachine series that support Local SSD, seeMachine series support.

• You can't use customer-supplied encryption keys or customer-managed encryptionkeys with Local SSD disks. Compute Engine automatically encryptsyour data when it's written to Local SSD storage.

• You can't back up Local SSD disks with snapshots, clones, machine images, orimages. Store important data on Hyperdisk or Persistent Diskvolumes.

Types of Local SSD disks

Local SSD disks come in two types:

• Titanium SSD: Titanium SSD is a custom-designed Local SSD diskthat usesTitanium I/O offload processing and offersenhanced SSD security, performance, and management. Titanium offershigher storage IOPS, throughput, and lower latency than the previousgeneration of Local SSD. The following machine series offer Local SSD storageusing Titanium SSD:

  • General-purpose:C4,C4A, andC4D machine series
  • Storage-optimized:Z3 machine series
  • Compute-optimized:H4D(Preview)
  • Accelerator-optimizedG4 machine series

  Titanium SSD disks are directly attached to the compute instancesinside their host server.

• Local SSD: Local SSD is the original local SSD feature for Google Cloud.Each Local SSD disk attached to an instance provides 375 GiB of capacity.These disks provide higher performance than Hyperdisk orPersistent Disk. You can use either the NVMe or SCSI interface to mount LocalSSD disks.

  Local SSD disks are directly attached to the instances inside their hostserver.

Unless Titanium SSD is specifically mentioned, the term"Local SSD" applies to both Local SSD and Titanium SSD when describingfeatures of local SSD disks.

Performance

Local SSD performance depends on several factors, including the number ofattached Local SSD disks, the selected disk interface(NVMe orSCSI), and the instance'smachine type. The available performance increases as you attach more Local SSDdisks to your instance.

Local SSD performance by number of attached disks

The following tables list the maximum IOPS and throughput for NVMe- andSCSI-attached Local SSD disks. The metrics are listed by the total capacity ofLocal SSD disks attached to the instance.

Titanium SSD performance

The following table lists the performance limits for Titanium SSD disks onC4,C4A,C4D,G4,H4D (Preview), andZ3 instances.

Machine type	# of attached Titanium SSD disks	Total storage space (GiB)	IOPS		Throughput (MiB/s)
			Read	Write	Read	Write
C4 (with 375 GiB disks)
c4-standard-4-lssd c4-highmem-4-lssd	1	375	150,000	75,000	625	330
c4-standard-8-lssd c4-highmem-8-lssd	1	375	150,000	75,000	625	330
c4-standard-16-lssd c4-highmem-16-lssd	2	750	300,000	150,000	1,250	660
c4-standard-24-lssd c4-highmem-24-lssd	4	1,500	600,000	300,000	2,500	1,320
c4-standard-32-lssd c4-highmem-32-lssd	5	1,875	750,000	375,000	3,125	1,650
c4-standard-48-lssd c4-highmem-48-lssd	8	3,000	1,200,000	600,000	5,000	2,640
c4-standard-96-lssd c4-highmem-96-lssd	16	6,000	2,400,000	1,200,000	10,000	5,280
c4-standard-144-lssd c4-highmem-144-lssd	24	9,000	3,600,000	1,800,000	15,000	7,920
c4-standard-192-lssd c4-highmem-192-lssd	32	12,000	4,800,000	2,400,000	20,000	10,560
c4-standard-288-lssd c4-highmem-288-lssd	48	18,000	7,200,000	3,600,000	30,000	15,840
C4A (with 375 GiB disks)
c4a-standard-4-lssd c4a-highmem-4-lssd	1	375	150,000	75,000	650	330
c4a-standard-8-lssd c4a-highmem-8-lssd	2	750	300,000	150,000	1,300	660
c4a-standard-16-lssd c4a-highmem-16-lssd	4	1,500	600,000	300,000	2,600	1,320
c4a-standard-32-lssd c4a-highmem-32-lssd	6	2,250	900,000	450,000	3,900	1,980
c4a-standard-48-lssd c4a-highmem-48-lssd	10	3,750	1,500,000	750,000	6,500	3,300
c4a-standard-64-lssd c4a-highmem-64-lssd	14	5,250	2,100,000	1,050,000	9,100	4,620
c4a-standard-72-lssd c4a-highmem-72-lssd	16	6,000	2,400,000	1,200,000	10,400	5,280
C4D (with 375 GiB disks)
c4d-standard-8-lssd c4d-highmem-8-lssd c4d-standard-16-lssd c4d-highmem-16-lssd	1	375	150,000	75,000	625	330
c4d-standard-32-lssd c4d-highmem-32-lssd	2	750	300,000	150,000	1,250	660
c4d-standard-48-lssd c4d-highmem-48-lssd	4	1,500	600,000	300,000	2,500	1,320
c4d-standard-64-lssd c4d-highmem-64-lssd	6	2,250	900,000	450,000	3,750	1,980
c4d-standard-96-lssd c4d-highmem-96-lssd	8	3,000	1,200,000	600,000	5,000	2,640
c4d-standard-192-lssd c4d-highmem-192-lssd	16	6,000	2,400,000	1,200,000	10,000	5,280
c4d-standard-384-lssd c4d-highmem-384-lssd	32	12,000	4,800,000	2,400,000	20,000	10,560
G4 (with 375 GiB disks)
g4-standard-48	4	1,500	600,000	300,000	2,500	1,320
g4-standard-96	8	3,000	1,200,000	600,000	5,000	2,640
g4-standard-192	16	6,000	2,400,000	1,200,000	10,000	5,280
g4-standard-384	32	12,000	4,800,000	2,400,000	20,000	10,560
H4D (with 375 GiB disks)
h4d-highmem-192-lssd	10	3,750	1,500,000	750,000	6,250	3,300
Z3 (with 3 TiB disks)
z3-highmem-8-highlssd z3-highmem-14-standardlssd	1	3,000	750,000	500,000	3,000	2,500
z3-highmem-16-highlssd z3-highmem-22-standardlssd	2	6,000	1,500,000	1,000,000	6,000	5,000
z3-highmem-22-highlssd z3-highmem-44-standardlssd	3	9,000	2,250,000	1,500,000	9,000	7,500
z3-highmem-32-highlssd	4	12,000	3,000,000	2,000,000	12,000	10,000
z3-highmem-44-highlssd z3-highmem-88-standard	6	18,000	4,500,000	3,000,000	18,000	15,000
z3-highmem-88-highlssd z3-highmem-176-standardlssd	12	36,000	9,000,000	6,000,000	36,000	30,000
Z3 bare metal (with 6 TiB disks)
z3-highmem-192-highlssd-metal	12	72,000	9,000,000	6,000,000	36,000	30,000

NVMe Local SSD performance

The following table lists the performance limits for Local SSD disks that areattached to instances using NVMe.

# of attached Local SSD disks	Total storage space (GiB)	Capacity per disk (GiB)	IOPS		Throughput (MiB/s)
			Read	Write	Read	Write
1	375	375	170,000	90,000	660	350
2	750	375	340,000	180,000	1,320	700
3	1,125	375	510,000	270,000	1,980	1,050
4	1,500	375	680,000	360,000	2,650	1,400
5	1,875	375	680,000	360,000	2,650	1,400
6	2,250	375	680,000	360,000	2,650	1,400
7	2,625	375	680,000	360,000	2,650	1,400
8	3,000	375	680,000	360,000	2,650	1,400
16	6,000	375	1,600,000	800,000	6,240	3,120
24	9,000	375	2,400,000	1,200,000	9,360	4,680
32	12,000	375	3,200,000	1,600,000	12,480	6,240

SCSI Local SSD performance

The following table lists the performance limits for Local SSD disks that areattached to instances using SCSI.

# of combined Local SSD disks	Storage space (GiB)	IOPS		Throughput (MiB/s)
		Read	Write	Read	Write
1	375	100,000	70,000	390	270
2	750	200,000	140,000	780	550
3	1,125	300,000	210,000	1,170	820
4	1,500	400,000	280,000	1,560	1,090
5	1,875	400,000	280,000	1,560	1,090
6	2,250	400,000	280,000	1,560	1,090
7	2,625	400,000	280,000	1,560	1,090
8	3,000	400,000	280,000	1,560	1,090
16	6,000	900,000	800,000	6,240	3,120
24	9,000	900,000	800,000	9,360	4,680

Configure your instance to maximize performance

To reach the stated performance levels, you must configure your compute instanceas follows:

• Attach the Local SSD disks with the NVMe interface. Disks attachedwith the SCSI interface have lower performance.

• The following machine types also require a minimum number of vCPUs to reachthese maximums:

  • N2,N2D,orA2 machine typesrequire at least 24 vCPUs.
  • N1 machine typesrequire at least 32 vCPUs.

• If your instance uses a custom Linux image, the image must use version 4.14.68or later of the Linux kernel. If you use the public images provided byCompute Engine, you don't have to take any further action.

For additional instance and disk configuration settings that can improve LocalSSD performance, seeOptimizing Local SSD performance.

For more information about selecting a disk interface,seeChoose a disk interface.

Local SSD data persistence

Compute Engine preserves the data on Local SSD disks in certain scenarios,and in other cases, Compute Engine does not guarantee Local SSD datapersistence.

The following information describes these scenarios and applies to each LocalSSD disk attached to an instance.

Scenarios where Compute Engine persists Local SSD data

Data on Local SSD disks persists only through the following events:

• If you reboot the guest operating system.
• If you configure your instance forlive migrationand the instance goes through a host maintenance event.
• If youopt to preserve the Local SSD data when you stop orsuspend the instance. This feature is inPreview.

Scenarios where Compute Engine might not persist Local SSD data

Data on Local SSD disks might be lost if ahost error occurs on the instance andCompute Engine can't reconnect the instance to the Local SSD disk within aspecified time.

You can control how much time, if any, is spent attempting to recoverthe data with the Local SSD recovery timeout. If Compute Engine can'treconnect to the disk before the timeout expires, the instance is restarted.When the instance restarts, the Local SSD data is unrecoverable.Compute Engine attaches a blank Local SSD disk to the restartedinstance.

The Local SSD recovery timeout is part of an instance's host maintenance policy.For more information, seeLocal SSD recovery timeout.

Scenarios where Compute Engine does not persist Local SSD data

Data on Local SSD disks does not persist through the following events:

• If you shut down the guest operating system and force the instance tostop.
• If you create aSpot VM orpreemptible VM and the VM goesthrough the preemption process.
• If you configure the instance tostop on host maintenance eventsand the instance goes through a host maintenance event.
• If you misconfigure the Local SSD so that it becomes unreachable.
• If you disable project billing, causing the instance to stop.

If Compute Engine was unable to recover an instance's Local SSD data,Compute Engine restarts the instance with a mounted and attached Local SSDdisk for each previously attached Local SSD disk.

Machine series support

You can use Local SSD disks with the following machine series.

Note: While you can use Local SSD disks with C4, C4D or C3 machine types, youcan't attach Local SSD disks to instances that usebare metal machine typesfor C4, C4D or C3 machine types.

However, there are constraints around how many Local SSD disks you canattach based on each machine type. For more information, seeChoose a valid number of Local SSD disks.

Local SSD encryption

Compute Engine automatically encrypts your data when it is written toLocal SSD disks. You can't usecustomer-supplied encryption keyswith Local SSD disks.

Local SSD data backup

Since you can't back up Local SSD data with disk images, standard snapshots, ordisk clones, Google recommends that you always store valuable data on adurable storage option.

If you need to preserve the data on a Local SSD disk, attach a Persistent Disk orGoogle Cloud Hyperdisk to the instance. After you mount the Persistent Disk orHyperdisk copy the data from the Local SSD disk to the newlyattached disk.

Choose a disk interface

To achieve the highest Local SSD performance, you must attach your disks to theinstance with the NVMe interface. Performance is lower if you use the SCSIinterface.

The disk interface you choose also depends on the machine type and OS that yourinstance uses. Some of the available machine types in Compute Engine allowyou to choose between NVMe and SCSI interfaces, while others support eitheronly NVMe or only SCSI. Similarly, some of the public OS images provided byCompute Engine might support both NVMe and SCSI, or only one of the two.

Disk interface support by machine type and OS image

The following pages provide more information about available machine types andsupported public images, as well as performance details.

• Supported interfaces by machine types: SeeMachine series comparison.In theChoose VM properties to compare list, selectDisk interface type.

• OS image: For a list of which public OS images provided by Compute Enginesupport SCSI or NVMe, see theInterfaces tab for each tablein the operating system details documentation.

Considerations for NVMe for custom images

If your instance uses a custom Linux image,you must use version 4.14.68 or later of the Linux kernel for optimal NVMeperformance.

Considerations for SCSI for custom images

If you have an existing setup that requires using a SCSI interface, considerusing multi-queue SCSI to achieve better performance over the standard SCSIinterface.

If you are using a custom image that you imported, seeEnable multi-queue SCSI.

Choose a valid number of Local SSD disks

Most machine types available on Compute Engine support Local SSD disks.Some machine types always include a fixed number of Local SSD disks by default,while others allow you to add specific numbers of disks. You can only add LocalSSD disks when you create the instance. You can't add Local SSD disks to aninstance after you create it.

• For VM instances created using the A4X machine series or storage-optimizedZ3 machine series, each attached Titanium SSD disk has a partition sizeof 3,000 GiB.
• For Z3 bare metal instances, each attached Titanium SSD disk has apartition size of 6,000 GiB.
• For all other machine series, each Titanium SSD or Local SSD disk attachedto the instance has a partition size of 375 GiB.

Machine types that automatically attach Local SSD disks

The following table lists the machine types that come with Local SSD disks bydefault. The table also shows the number of these disks that are attached whenyou create the instance.

Machine type	Number of Local SSD disks automatically attached per instance
C4 using Titanium SSD
Only the-lssd variants of the C4 machine types support local Titanium SSD.
c4-standard-4-lssd c4-highmem-4-lssd	1
c4-standard-8-lssd c4-highmem-8-lssd	1
c4-standard-16-lssd c4-highmem-16-lssd	2
c4-standard-24-lssd c4-highmem-24-lssd	4
c4-standard-32-lssd c4-highmem-32-lssd	5
c4-standard-48-lssd c4-highmem-48-lssd	8
c4-standard-96-lssd c4-highmem-96-lssd	16
c4-standard-144-lssd c4-highmem-144-lssd	24
c4-standard-192-lssd c4-highmem-192-lssd	32
c4-standard-288-lssd c4-highmem-288-lssd	48
C4A using Titanium SSD
Only the-lssd variants of the C4A machine types support local Titanium SSD.
c4a-standard-4-lssd c4a-highmem-4-lssd	1
c4a-standard-8-lssd c4a-highmem-8-lssd	2
c4a-standard-16-lssd c4a-highmem-16-lssd	4
c4a-standard-32-lssd c4a-highmem-32-lssd	6
c4a-standard-48-lssd c4a-highmem-48-lssd	10
c4a-standard-64-lssd c4a-highmem-64-lssd	14
c4a-standard-72-lssd c4a-highmem-72-lssd	16
C4D machine types
Only the-lssd variants of the C4D machine types support Local SSD.
c4d-standard-8-lssd c4d-highmem-8-lssd	1
c4d-standard-16-lssd c4d-highmem-16-lssd	1
c4d-standard-32-lssd c4d-highmem-32-lssd	2
c4d-standard-48-lssd c4d-highmem-48-lssd	4
c4d-standard-64-lssd c4d-highmem-64-lssd	6
c4d-standard-96-lssd c4d-highmem-96-lssd	8
c4d-standard-192-lssd c4d-highmem-192-lssd	16
c4d-standard-384-lssd c4d-highmem-384-lssd	32
C3
Only the-lssd variants of the C3 machine types support Local SSD.
c3-standard-4-lssd	1
c3-standard-8-lssd	2
c3-standard-22-lssd	4
c3-standard-44-lssd	8
c3-standard-88-lssd	16
c3-standard-176-lssd	32
C3D
Only the-lssd variants of the C3D machine types support Local SSD.
c3d-standard-8-lssd c3d-highmem-8-lssd	1
c3d-standard-16-lssd c3d-highmem-16-lssd	1
c3d-standard-30-lssd c3d-highmem-30-lssd	2
c3d-standard-60-lssd c3d-highmem-60-lssd	4
c3d-standard-90-lssd c3d-highmem-90-lssd	8
c3d-standard-180-lssd c3d-highmem-180-lssd	16
c3d-standard-360-lssd c3d-highmem-360-lssd	32
H4D (Preview)
h4d-highmem-192-lssd	10
A4X
a4x-highgpu-4g	4
A4
a4-highgpu-8g	32
A3 Ultra
a3-ultragpu-8g	32
A3 Mega
a3-megagpu-8g	16
A3 High
a3-highgpu-1g	2
a3-highgpu-2g	4
a3-highgpu-4g	8
a3-highgpu-8g	16
A3 Edge
a3-edgegpu-8g	16
A2 Ultra
a2-ultragpu-1g	1
a2-ultragpu-2g	2
a2-ultragpu-4g	4
a2-ultragpu-8g	8
Z3 using Titanium SSD
Each disk is 3 TiB in size:
z3-highmem-8-highlssd z3-highmem-14-standardlssd-highlssd	1
z3-highmem-16-highlssd z3-highmem-22-standardlssd	2
z3-highmem-22-highlssd z3-highmem-44-standardlssd	3
z3-highmem-32-highlssd	4
z3-highmem-44-highlssd z3-highmem-88-standardlssd	6
z3-highmem-88-highlssd z3-highmem-176-standardlssd-standardlssd	12
Each disk is 6 TiB in size:
z3-highmem-192-highlssd-metal	12

Machine types that require you to choose a number of Local SSD disks

The machine types listed in the following table don't attach Local SSD disks toa newly created instance unless you specify how many disks to attach. Becauseyou can add Local SSD disks only during instance creation, use the informationin this section to determine how many Local SSD disks to attach when you createan instance.

Machine type	Number of Local SSD disks allowed per instance
N1
Machine types with T4 GPUs	1 to 8, 16
All other machine types	1 to 8, 16, or 24
N2
Machine types with 2 to 10 vCPUs, inclusive	1, 2, 4, 8, 16, or 24
Machine types with 12 to 20 vCPUs, inclusive	2, 4, 8, 16, or 24
Machine types with 22 to 40 vCPUs, inclusive	4, 8, 16, or 24
Machine types with 42 to 80 vCPUs, inclusive	8, 16, or 24
Machine types with 82 to 128 vCPUs, inclusive	16 or 24
N2D
Machine types with 2 to 16 vCPUs, inclusive	1, 2, 4, 8, 16, or 24
Machine types with 32 or 48 vCPUs	2, 4, 8, 16, or 24
Machine types with 64 or 80 vCPUs	4, 8, 16, or 24
Machine types with 96 to 224 vCPUs, inclusive	8, 16, or 24
C2
Machine types with 4 or 8 vCPUs	1, 2, 4, or 8
Machine types with 16 vCPUs	2, 4, or 8
Machine types with 30 vCPUs	4 or 8
Machine types with 60 vCPUs	8
C2D
Machine types with 2 to 16 vCPUs, inclusive	1, 2, 4, 8
Machine types with 32 vCPUs	2, 4, 8
Machine types with 56 vCPUs	4, 8
Machine types with 112 vCPUs	8
A2 Standard
a2-highgpu-1g	1, 2, 4, or 8
a2-highgpu-2g	2, 4, or 8
a2-highgpu-4g	4 or 8
a2-highgpu-8g ora2-megagpu-16g	8
G2
g2-standard-4	1
g2-standard-8	1
g2-standard-12	1
g2-standard-16	1
g2-standard-24	2
g2-standard-32	1
g2-standard-48	4
g2-standard-96	8
G4 using Titanium SSD
g4-standard-48	4
g4-standard-96	8
g4-standard-192	16
g4-standard-384	32
M1
m1-ultramem-40	1 to 5
m1-ultramem-80	1 to 8
m1-megamem-96	Not available
m1-ultramem-160	Not available
M3
m3-ultramem-32	4, 8
m3-megamem-64	4, 8
m3-ultramem-64	4, 8
m3-megamem-128	8
m3-ultramem-128	8

Reserve capacity for Local SSD disks

Reservations provide high assurance of capacity for zone-specific resources,including Local SSD disks. You can use reservations to ensure that you haveLocal SSD disks available when you need to use them for growth or disasterrecovery. For the different methods to reserve zone-specific resources inCompute Engine, seeChoose a reservation type.

For most machine series, reservations are also useful when you want toreceivecommitted use discounts (CUDs) for your Local SSD disks.

Pricing

For each Local SSD disk you create, you are billed for the total capacity ofthe disk for the lifetime of the instance that it is attached to.

For detailed information about Local SSD pricing and available discounts,seeLocal SSD pricing.

For Titanium SSD pricing, see the pricing for the machine series on theVM instance pricing page. Forexample, for the pricing for Titanium SSD attached to a Z3 instance,see theZ3 instance pricing.

Local SSD disks and Spot VM instances

If you start aSpot VM or preemptible VMwith a Local SSD disk, Compute Engine charges discountedspot pricesfor the Local SSD usage. Local SSD disks that are attached to Spot VMs orpreemptible VMs work like normal Local SSD disks, retain the samedata persistence characteristics,and remain attached for the life of the VM.

Compute Engine doesn't charge you for Local SSD disk usage on aSpot VM or preemptible VM if the VM is preempted within a minute after itstarts running.

Committed use discounts for Local SSD disks

Resource-based commitments provide deep discounts forCompute Engine resources in return for committing to using the resourcesin a specific region for at least one year. You typically purchase commitmentsfor resources (vCPUs, memory, GPUs, and Local SSD disks) of a specific machineseries. When you use your resources, you receive qualifying resource usage atdiscounted prices. To learn more about these discounts, seeResource-based committed use discounts.

To purchase a commitment with Local SSD disks for most machine series, youmust also reserve the disks and attach the reservations to your commitment. Ifyou're committing to purchasing any local Titanium SSD disks for use withthe following instances, then you don't need attached reservations for thosedisks:

• C4
• C4A
• C4D
• H4D
• Z3

For more information about attaching reservations tocommitments, seeAttach reservations to resource-based commitments.

Use Local SSD disks with an instance

To use a Local SSD disk with a compute instance, you must complete thefollowing steps:

• Add Local SSD disks when you create an instance.
• Format and mount Local SSD disksthat you added to your instance.

Device naming on Linux instances

The Linux device names for the disks attached to your instance depend on theinterface that you choose when creating the disks. When you use thelsblkoperating system command to view your disk devices, it displays the prefixnvme for disks attached with the NVMe interface, and the prefixsd fordisks attached with the SCSI interface.

The ordering of the disk numbers or NVMe controllers is not predictable orconsistent across instance restarts. On the first boot, a disk might benvme0n1 (orsda for SCSI). On the second boot, the device name for the samedisk might benvme2n1 ornvme0n3 (orsdc for SCSI).

When accessing attached disks, you should use the symbolic links created in/dev/disk/by-id/ instead. These names persist across reboots.For more information about symlinks, seeSymbolic links for disks attached to an instance.

For more information about device names, seeDevice naming on Linux instances.

Stop or suspend a Compute Engine instance with Local SSD disks

When youstop orsuspend an instance,Compute Engine discards the data of anyLocal SSD disks attached to the instance by default. When you resume theinstance, all Local SSD disks attached to the instance are blank.

Preserve Local SSD data when you stop or suspend an instance

Preview — Preserving Local SSD data

This feature is subject to the "Pre-GA Offerings Terms" in the General Service Terms section of theService Specific Terms. Pre-GA features are available "as is" and might have limited support. For more information, see thelaunch stage descriptions.

When you stop or suspend a compute instance, you can optionally preserve thedata on the Local SSD disks attached to the instance.

When the stop or suspend operation starts, Compute Engineperforms a managed migration of the Local SSD disk data to durable storage.When you resume or restart the instance, Compute Engine copies thepreserved data to Local SSD disks attached to the instance. After you resume orrestart the instance, you might have toremount the Local SSD disk into the file system.

Warning: In the unlikely event that a hardware failure occurs whileCompute Engine is copying the Local SSD data, Compute Engineattempts to preserve the Local SSD data. However, the data might be lost orcorrupted when you restart or resume the instance if the attempt wasunsuccessful.

You're billed for the storage space used to preserve the Local SSD data untilyou restart or resume the instance. The used storage space consumes yourproject'sPersistent disk standard GB quota.

Limitations

• Preserving Local SSD data is inPreviewonly and is not covered under the GA terms for Compute Engine.
• Preserving Local SSD data isn't available for machine types that useTitanium SSD.
• You can't preserve Local SSD data for disks that have custom device names.You can only preserve Local SSD data for a disk that has a defaultdevice name,for examplelocal-ssd-0.
• You can't preserve the Local SSD data if you stop or suspend an instancethat has more than 32 Local SSD disksattached.
• You can't preserve Local SSD data if you stop or suspend an instance fromthe Google Cloud console.
• Saving the Local SSD data begins only after the suspend or stop operationstarts.
• Restoring the Local SSD data is a background process that begins after theinstance starts. Reading data that isn't already restored triggers animmediate restoration of the requested data.
• If you're using Spot VMs or preemptible VMs and you opt to preserveLocal SSD data during a suspend or stop operation,then theLocal SSD data is lost if Compute Engine preempts theinstance during the stop or suspend operation.

To learn how to preserve Local SSD data when you stop or suspend an instance,seeStop an instance with Local SSD disksandSuspend an instance with Local SSD disks,respectively.

Delete Local SSD disks

To remove or delete Local SSD disks, you must delete the compute instance thatthe disks are attached to. You can't delete Local SSD disks unless you deletethe instance.

Before youdelete a Compute Engine instancethat has Local SSD disks attached, make sure that you migrate any critical dataon the Local SSD disks to a Persistent Disk, Hyperdisk, or toanother instance. Otherwise, the data on the Local SSD disks ispermanently lost.

What's next

Learn how toCreate a compute instance with Local SSD disks.