diff --git a/mon/make-osd-hybrid.js b/mon/make-osd-hybrid.js
deleted file mode 100755
index f760804c..00000000
--- a/mon/make-osd-hybrid.js
+++ /dev/null
@@ -1,415 +0,0 @@
-#!/usr/bin/nodejs
-// DEPRECATED, DO NOT USE - use vitastor-disk prepare instead
-// systemd unit generator for hybrid (HDD+SSD) vitastor OSDs
-// Copyright (c) Vitaliy Filippov, 2019+
-// License: VNPL-1.1
-
-// USAGE: nodejs make-osd-hybrid.js [--disable_ssd_cache 0] [--disable_hdd_cache 0] /dev/sda /dev/sdb /dev/sdc /dev/sdd ...
-// I.e. - just pass all HDDs and SSDs mixed, the script will decide where
-// to put journals on its own
-
-const fs = require('fs');
-const fsp = fs.promises;
-const child_process = require('child_process');
-
-const options = {
-    debug: 1,
-    journal_size: 1024*1024*1024,
-    min_meta_size: 1024*1024*1024,
-    object_size: 1024*1024,
-    bitmap_granularity: 4096,
-    device_block_size: 4096,
-    disable_ssd_cache: 1,
-    disable_hdd_cache: 1,
-};
-
-run().catch(console.fatal);
-
-async function run()
-{
-    const device_list = parse_options();
-    await system_or_die("mkdir -p /var/log/vitastor; chown vitastor /var/log/vitastor");
-    // Collect devices
-    const all_devices = await collect_devices(device_list);
-    const ssds = all_devices.filter(d => d.ssd);
-    const hdds = all_devices.filter(d => !d.ssd);
-    // Collect existing OSD units
-    const osd_units = await collect_osd_units();
-    // Count assigned HDD journals and unallocated space for each SSD
-    await check_journal_count(ssds, osd_units);
-    // Create new OSDs
-    await create_new_hybrid_osds(hdds, ssds, osd_units);
-    process.exit(0);
-}
-
-function parse_options()
-{
-    const devices = [];
-    const opt = {};
-    for (let i = 2; i < process.argv.length; i++)
-    {
-        const arg = process.argv[i];
-        if (arg == '--help' || arg == '-h')
-        {
-            opt.help = true;
-            break;
-        }
-        else if (arg.substr(0, 2) == '--')
-            opt[arg.substr(2)] = process.argv[++i];
-        else
-            devices.push(arg);
-    }
-    if (opt.help || !devices.length)
-    {
-        console.log(
-            'Prepare hybrid (HDD+SSD) Vitastor OSDs\n'+
-            '(c) Vitaliy Filippov, 2019+, license: VNPL-1.1\n\n'+
-            'USAGE: nodejs make-osd-hybrid.js [OPTIONS] /dev/sda /dev/sdb /dev/sdc ...\n'+
-            'Just pass all your SSDs and HDDs in any order, the script will distribute OSDs for you.\n\n'+
-            'OPTIONS (with defaults):\n'+
-            Object.keys(options).map(k => `  --${k} ${options[k]}`).join('\n')
-        );
-        process.exit(0);
-    }
-    for (const k in opt)
-        options[k] = opt[k];
-    return devices;
-}
-
-// Collect devices
-async function collect_devices(devices_to_check)
-{
-    const devices = [];
-    for (const dev of devices_to_check)
-    {
-        if (dev.substr(0, 5) != '/dev/')
-        {
-            console.log(`${dev} does not start with /dev/, skipping`);
-            continue;
-        }
-        if (!await file_exists('/sys/block/'+dev.substr(5)))
-        {
-            console.log(`${dev} is a partition, skipping`);
-            continue;
-        }
-        // Check if the device is an SSD
-        const rot = '/sys/block/'+dev.substr(5)+'/queue/rotational';
-        if (!await file_exists(rot))
-        {
-            console.log(`${dev} does not have ${rot} to check whether it's an SSD, skipping`);
-            continue;
-        }
-        const ssd = !parseInt(await fsp.readFile(rot, { encoding: 'utf-8' }));
-        // Check if the device has partition table
-        let [ has_partition_table, parts ] = await system(`sfdisk --dump ${dev} --json`);
-        if (has_partition_table != 0)
-        {
-            // Check if the device has any data
-            const [ has_data, out ] = await system(`blkid -p ${dev}`);
-            if (has_data == 0)
-            {
-                console.log(`${dev} contains data, skipping:\n  ${out.trim().replace(/\n/g, '\n  ')}`);
-                continue;
-            }
-        }
-        parts = parts ? JSON.parse(parts).partitiontable : null;
-        if (parts && parts.label != 'gpt')
-        {
-            console.log(`${dev} contains "${parts.label}" partition table, only GPT is supported, skipping`);
-            continue;
-        }
-        devices.push({
-            path: dev,
-            ssd,
-            parts,
-        });
-    }
-    return devices;
-}
-
-// Collect existing OSD units
-async function collect_osd_units()
-{
-    const units = [];
-    for (const unit of (await system("ls /etc/systemd/system/vitastor-osd*.service"))[1].trim().split('\n'))
-    {
-        if (!unit)
-        {
-            continue;
-        }
-        let cmd = /^ExecStart\s*=\s*(([^\n]*\\\n)*[^\n]*)/.exec(await fsp.readFile(unit, { encoding: 'utf-8' }));
-        if (!cmd)
-        {
-            console.log('ExecStart= not found in '+unit+', skipping')
-            continue;
-        }
-        let kv = {}, key;
-        cmd = cmd[1].replace(/^bash\s+-c\s+'/, '')
-            .replace(/>>\s*\S+2>\s*&1\s*'$/, '')
-            .replace(/\s*\\\n\s*/g, ' ')
-            .replace(/([^\s']+)|'([^']+)'/g, (m, m1, m2) =>
-            {
-                m1 = m1||m2;
-                if (key == null)
-                {
-                    if (m1.substr(0, 2) != '--')
-                    {
-                        console.log('Strange command line in '+unit+', stopping');
-                        process.exit(1);
-                    }
-                    key = m1.substr(2);
-                }
-                else
-                {
-                    kv[key] = m1;
-                    key = null;
-                }
-            });
-        units.push(kv);
-    }
-    return units;
-}
-
-// Count assigned HDD journals and unallocated space for each SSD
-async function check_journal_count(ssds, osd_units)
-{
-    const units_by_journal = osd_units.reduce((a, c) =>
-    {
-        if (c.journal_device)
-            a[c.journal_device] = c;
-        return a;
-    }, {});
-    for (const dev of ssds)
-    {
-        dev.journals = 0;
-        if (dev.parts)
-        {
-            for (const part of dev.parts.partitions)
-            {
-                if (part.uuid && units_by_journal['/dev/disk/by-partuuid/'+part.uuid.toLowerCase()])
-                {
-                    dev.journals++;
-                }
-            }
-            dev.free = free_from_parttable(dev.parts);
-        }
-        else
-        {
-            dev.free = parseInt(await system_or_die("blockdev --getsize64 "+dev.path));
-        }
-    }
-}
-
-async function create_new_hybrid_osds(hdds, ssds, osd_units)
-{
-    const units_by_disk = osd_units.reduce((a, c) => { a[c.data_device] = c; return a; }, {});
-    for (const dev of hdds)
-    {
-        if (!dev.parts)
-        {
-            // HDD is not partitioned yet, create a single partition
-            // + is the "default value" for sfdisk
-            await system_or_die('sfdisk '+dev.path, 'label: gpt\n\n+ +\n');
-            dev.parts = JSON.parse(await system_or_die('sfdisk --dump '+dev.path+' --json')).partitiontable;
-        }
-        if (dev.parts.partitions.length != 1)
-        {
-            console.log(dev.path+' has more than 1 partition, skipping');
-        }
-        else if ((dev.parts.partitions[0].start + dev.parts.partitions[0].size) != (1 + dev.parts.lastlba))
-        {
-            console.log(dev.path+'1 is not a whole-disk partition, skipping');
-        }
-        else if (!dev.parts.partitions[0].uuid)
-        {
-            console.log(dev.parts.partitions[0].node+' does not have UUID. Please repartition '+dev.path+' with GPT');
-        }
-        else if (!units_by_disk['/dev/disk/by-partuuid/'+dev.parts.partitions[0].uuid.toLowerCase()])
-        {
-            await create_hybrid_osd(dev, ssds);
-        }
-    }
-}
-
-async function create_hybrid_osd(dev, ssds)
-{
-    // Create a new OSD
-    // Calculate metadata size
-    const data_device = '/dev/disk/by-partuuid/'+dev.parts.partitions[0].uuid.toLowerCase();
-    const data_size = dev.parts.partitions[0].size * dev.parts.sectorsize;
-    const meta_entry_size = 24 + 2*options.object_size/options.bitmap_granularity/8;
-    const entries_per_block = Math.floor(options.device_block_size / meta_entry_size);
-    const object_count = Math.floor(data_size / options.object_size);
-    let meta_size = Math.ceil(1 + object_count / entries_per_block) * options.device_block_size;
-    // Leave some extra space for future metadata formats and round metadata area size to multiples of 1 MB
-    meta_size = 2*meta_size;
-    meta_size = Math.ceil(meta_size/1024/1024) * 1024*1024;
-    if (meta_size < options.min_meta_size)
-        meta_size = options.min_meta_size;
-    let journal_size = Math.ceil(options.journal_size/1024/1024) * 1024*1024;
-    // Pick an SSD for journal, balancing the number of journals across SSDs
-    let selected_ssd;
-    for (const ssd of ssds)
-        if (ssd.free >= (meta_size+journal_size) && (!selected_ssd || selected_ssd.journals > ssd.journals))
-            selected_ssd = ssd;
-    if (!selected_ssd)
-    {
-        console.error('Could not find free space for SSD journal and metadata for '+dev.path);
-        process.exit(1);
-    }
-    // Allocate an OSD number
-    const osd_num = (await system_or_die("vitastor-cli alloc-osd")).trim();
-    if (!osd_num)
-    {
-        console.error('Failed to run vitastor-cli alloc-osd');
-        process.exit(1);
-    }
-    console.log('Creating OSD '+osd_num+' on '+dev.path+' (HDD) with journal and metadata on '+selected_ssd.path+' (SSD)');
-    // Add two partitions: journal and metadata
-    const new_parts = await add_partitions(selected_ssd, [ journal_size, meta_size ]);
-    selected_ssd.journals++;
-    const journal_device = '/dev/disk/by-partuuid/'+new_parts[0].uuid.toLowerCase();
-    const meta_device = '/dev/disk/by-partuuid/'+new_parts[1].uuid.toLowerCase();
-    // Wait until the device symlinks appear
-    while (!await file_exists(journal_device))
-    {
-        await new Promise(ok => setTimeout(ok, 100));
-    }
-    while (!await file_exists(meta_device))
-    {
-        await new Promise(ok => setTimeout(ok, 100));
-    }
-    // Zero out metadata and journal
-    await system_or_die("dd if=/dev/zero of="+journal_device+" bs=1M count="+(journal_size/1024/1024)+" oflag=direct");
-    await system_or_die("dd if=/dev/zero of="+meta_device+" bs=1M count="+(meta_size/1024/1024)+" oflag=direct");
-    // Create unit file for the OSD
-    const has_scsi_cache_type = options.disable_ssd_cache &&
-        (await system("ls /sys/block/"+selected_ssd.path.substr(5)+"/device/scsi_disk/*/cache_type"))[0] == 0;
-    const write_through = options.disable_ssd_cache && (
-        has_scsi_cache_type || selected_ssd.path.substr(5, 4) == 'nvme'
-        && (await system_or_die("/sys/block/"+selected_ssd.path.substr(5)+"/queue/write_cache")).trim() == "write through");
-    await fsp.writeFile('/etc/systemd/system/vitastor-osd'+osd_num+'.service',
-`[Unit]
-Description=Vitastor object storage daemon osd.${osd_num}
-After=network-online.target local-fs.target time-sync.target
-Wants=network-online.target local-fs.target time-sync.target
-PartOf=vitastor.target
-
-[Service]
-LimitNOFILE=1048576
-LimitNPROC=1048576
-LimitMEMLOCK=infinity
-ExecStart=bash -c '/usr/bin/vitastor-osd \\
-    --osd_num ${osd_num} ${write_through
-        ? "--disable_meta_fsync 1 --disable_journal_fsync 1 --immediate_commit "+(options.disable_hdd_cache ? "all" : "small")
-        : ""} \\
-    --throttle_small_writes 1 \\
-    --disk_alignment ${options.device_block_size} \\
-    --journal_block_size ${options.device_block_size} \\
-    --meta_block_size ${options.device_block_size} \\
-    --journal_no_same_sector_overwrites true \\
-    --journal_sector_buffer_count 1024 \\
-    --block_size ${options.object_size} \\
-    --data_device ${data_device} \\
-    --journal_device ${journal_device} \\
-    --meta_device ${meta_device} >>/var/log/vitastor/osd${osd_num}.log 2>&1'
-WorkingDirectory=/
-ExecStartPre=+chown vitastor:vitastor ${data_device}
-ExecStartPre=+chown vitastor:vitastor ${journal_device}
-ExecStartPre=+chown vitastor:vitastor ${meta_device}${
-    has_scsi_cache_type
-    ? "\nExecStartPre=+bash -c 'D=$$$(readlink "+journal_device+"); echo write through > $$$(dirname /sys/block/*/$$\${D##*/})/device/scsi_disk/*/cache_type'"
-    : ""}${
-    options.disable_hdd_cache
-    ? "\nExecStartPre=+bash -c 'D=$$$(readlink "+data_device+"); echo write through > $$$(dirname /sys/block/*/$$\${D##*/})/device/scsi_disk/*/cache_type'"
-    : ""}
-User=vitastor
-PrivateTmp=false
-TasksMax=infinity
-Restart=always
-StartLimitInterval=0
-RestartSec=10
-
-[Install]
-WantedBy=vitastor.target
-`);
-    await system_or_die("systemctl enable vitastor-osd"+osd_num);
-}
-
-async function add_partitions(dev, sizes)
-{
-    let script = 'label: gpt\n\n';
-    if (dev.parts)
-    {
-        // Old partitions
-        for (const part of dev.parts.partitions)
-        {
-            script += part.node+': '+Object.keys(part).map(k => k == 'node' ? '' : k+'='+part[k]).filter(k => k).join(', ')+'\n';
-        }
-    }
-    // New partitions
-    for (const size of sizes)
-    {
-        script += '+ '+Math.ceil(size/1024)+'KiB\n';
-    }
-    await system_or_die('sfdisk '+dev.path, script);
-    // Get new partition table and find the new partition
-    const newpt = JSON.parse(await system_or_die('sfdisk --dump '+dev.path+' --json')).partitiontable;
-    const old_nodes = dev.parts ? dev.parts.partitions.reduce((a, c) => { a[c.uuid] = true; return a; }, {}) : {};
-    const new_nodes = newpt.partitions.filter(part => !old_nodes[part.uuid]);
-    if (new_nodes.length != sizes.length)
-    {
-        console.error('Failed to partition '+dev.path+': new partitions not found in table');
-        process.exit(1);
-    }
-    dev.parts = newpt;
-    dev.free = free_from_parttable(newpt);
-    return new_nodes;
-}
-
-function free_from_parttable(pt)
-{
-    let free = pt.lastlba + 1 - pt.firstlba;
-    for (const part of pt.partitions)
-    {
-        free -= part.size;
-    }
-    free *= pt.sectorsize;
-    return free;
-}
-
-async function system_or_die(cmd, input = '')
-{
-    let [ exitcode, stdout, stderr ] = await system(cmd, input);
-    if (exitcode != 0)
-    {
-        console.error(cmd+' failed: '+stderr);
-        process.exit(1);
-    }
-    return stdout;
-}
-
-async function system(cmd, input = '')
-{
-    if (options.debug)
-    {
-        process.stderr.write('+ '+cmd+(input ? " <<EOF\n"+input.replace(/\s*$/, '\n')+"EOF" : '')+'\n');
-    }
-    const cp = child_process.spawn(cmd, { shell: true });
-    let stdout = '', stderr = '', finish_cb;
-    cp.stdout.on('data', buf => stdout += buf.toString());
-    cp.stderr.on('data', buf => stderr += buf.toString());
-    cp.on('exit', () => finish_cb && finish_cb());
-    cp.stdin.write(input);
-    cp.stdin.end();
-    if (cp.exitCode == null)
-    {
-        await new Promise(ok => finish_cb = ok);
-    }
-    return [ cp.exitCode, stdout, stderr ];
-}
-
-async function file_exists(filename)
-{
-    return new Promise((ok, no) => fs.access(filename, fs.constants.R_OK, err => ok(!err)));
-}
diff --git a/mon/make-osd.sh b/mon/make-osd.sh
deleted file mode 100755
index 72be88f8..00000000
--- a/mon/make-osd.sh
+++ /dev/null
@@ -1,66 +0,0 @@
-#!/bin/bash
-# DEPRECATED, DO NOT USE - use vitastor-disk prepare instead
-# Very simple systemd unit generator for vitastor-osd services
-# Copyright (c) Vitaliy Filippov, 2019+
-# License: MIT
-
-# USAGE:
-# 1) Put etcd_address and osd_network into /etc/vitastor/vitastor.conf. Example:
-#    {
-#        "etcd_address":["http://10.200.1.10:2379/v3","http://10.200.1.11:2379/v3","http://10.200.1.12:2379/v3"],
-#        "osd_network":"10.200.1.0/24"
-#    }
-# 2) Run ./make-osd.sh /dev/disk/by-partuuid/xxx [ /dev/disk/by-partuuid/yyy]...
-
-set -e -x
-
-# Create OSDs on all passed devices
-for DEV in $*; do
-
-OSD_NUM=$(vitastor-cli alloc-osd)
-
-echo Creating OSD $OSD_NUM on $DEV
-
-OPT=$(vitastor-disk simple-offsets --format options $DEV | tr '\n' ' ')
-META=$(vitastor-disk simple-offsets --format json $DEV | jq .data_offset)
-dd if=/dev/zero of=$DEV bs=1048576 count=$(((META+1048575)/1048576)) oflag=direct
-
-mkdir -p /var/log/vitastor
-id vitastor &>/dev/null || useradd vitastor
-chown vitastor /var/log/vitastor
-
-cat >/etc/systemd/system/vitastor-osd$OSD_NUM.service <<EOF
-[Unit]
-Description=Vitastor object storage daemon osd.$OSD_NUM
-After=network-online.target local-fs.target time-sync.target
-Wants=network-online.target local-fs.target time-sync.target
-PartOf=vitastor.target
-
-[Service]
-LimitNOFILE=1048576
-LimitNPROC=1048576
-LimitMEMLOCK=infinity
-ExecStart=bash -c '/usr/bin/vitastor-osd \\
-    --osd_num $OSD_NUM \\
-    --disable_data_fsync 1 \\
-    --immediate_commit all \\
-    --disk_alignment 4096 --journal_block_size 4096 --meta_block_size 4096 \\
-    --journal_no_same_sector_overwrites true \\
-    --journal_sector_buffer_count 1024 \\
-    $OPT >>/var/log/vitastor/osd$OSD_NUM.log 2>&1'
-WorkingDirectory=/
-ExecStartPre=+chown vitastor:vitastor $DEV
-User=vitastor
-PrivateTmp=false
-TasksMax=infinity
-Restart=always
-StartLimitInterval=0
-RestartSec=10
-
-[Install]
-WantedBy=vitastor.target
-EOF
-
-systemctl enable vitastor-osd$OSD_NUM
-
-done
diff --git a/mon/merge.js b/tests/merge.js
similarity index 100%
rename from mon/merge.js
rename to tests/merge.js
diff --git a/tests/test_snapshot.sh b/tests/test_snapshot.sh
index 661fe895..cda2e4e6 100755
--- a/tests/test_snapshot.sh
+++ b/tests/test_snapshot.sh
@@ -36,7 +36,7 @@ qemu-img convert -S 4096 -p \
     -f raw "vitastor:etcd_host=127.0.0.1\:$ETCD_PORT/v3:image=testimg" \
     -O raw ./testdata/layer1.bin
 
-node mon/merge.js ./testdata/layer0.bin ./testdata/layer1.bin ./testdata/check.bin
+node tests/merge.js ./testdata/layer0.bin ./testdata/layer1.bin ./testdata/check.bin
 
 cmp ./testdata/merged.bin ./testdata/check.bin